Tag: evolution

And then the plant said…

Do plants deliberately deceive insects?

Keith S. Taber

Do plants deceive insects by deliberately pretending to be rotting meat? (Spoiler alert. No, they do not.)
[Image credits: Rafflesia – Maizal, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons; Amorphophallus titanum – ailing moose, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons; fly and beetle – by Clker-Free-Vector-Images from Pixabay]

Mysterious plants

Earlier this week I heard an episode of BBC Radio 4's 'Start the Week' programme entitled 'Mysterious Plants' 1 (which can be heard here). It is always good to hear science-related episodes of series such as this. The mysterious plants included Amorphophallus titanum 2 believed to have the largest un-branched inflorescence of any plant in the world; and the parasitic genus Rafflesia, one species of which is thought to have the largest individual flowers in the world. 3

I could not help notice, however, that according to the guests, some plants are sentient beings, able to reflect on their circumstances, and to deliberately act in the world. Botanist Dr Chris Thorogood (of University of Oxford's Oxford Botanic Garden and Arboretum) described the parasitic plant Rafflesia as being 'pretty sneaky'. This is anthropomorphic, because – if taken literally – it implies deliberate behaviour.

No insects were deceived in the making of this programme

He was outdone, in this sense though, by evolutionary chemical ecologist Dr Kelsey Byers (of The John Innes Centre, Norwich) who told listeners,

"So these flies and beetles like to lay their eggs on rotting meat', and the flower goes 'oh, what if I also looked and smelled like rotting meat', or like the Amorphophallus titanum you might see at Kew Gardens for example, 'what if I also emitted heat, just like a pile of rotting meat?' …

So, what it's attracting are flies and beetles that essentially are going 'Ooh, that smells like food, that looks like food, I'm going to lay my eggs here, it's going to be great, my babies will have a great chance to survive'.

But there's, there's no food, it is deceiving them, it's basically saying 'I'm, mimicking the food, come and stay'."

Dr Kelsey Byer speaking on Radio 4

Now, I assume that Dr Byers does not intend this as a literal account of the biology discussed. In strict scientific terms, it is rather misleading

  • "flies and beetles like to lay their eggs on rotting meat"

I get a little uneasy when non human entities are described as liking things, as this does not reflect the subjective human experience of liking, say chocolate or Pink Floyd. But this unease probably links to the common alternative conception that students acquire in chemistry that atoms 'like' or 'want' full shells of electrons. Dr Byers could quite reasonably suggest that "flies and beetles tend to lay their eggs on rotting meat"; that their behaviour reflects a preference; and that is what 'likes' means. Fair enough.

  • "the flower goes 'oh, what if I also looked and smelled like rotting meat' … 'what if I also emitted heat, just like a pile of rotting meat?'…"

Now, flowers do not express themselves in language, and in any case (I'm fairly certain) do not have thoughts to potentially be expressed in language. Plato (2008) has his spokesperson Timaeus suggest that plants were "the kind of living being that…knows nothing of belief, reasoning, and intelligence". 4 So, no, plants do not do this – at least not literally.

  • "flies and beetles essentially are going 'Ooh, that smells like food, that looks like food, I'm going to lay my eggs here, it's going to be great, my babies will have a great chance to survive'…"

So insects are animals, and I can be less sure they do not have any kind of thought processes. (But it seems likely conscious thought requires a much more complex nervous system than that of any insect.) The 'essentially' means that Dr Byers is not suggesting they are directly expressing these ideas, but only indirectly (perhaps, those behavioural preferences again?) But I am pretty sure that even if insects could be said to 'think' at some level, they do not have formal concepts of food. I do not doubt that the fly experiences something when it eats that is different to when it is not eating, but I really doubt it is meaningful to suggest a fly has any concept of eating or can be said to 'know' when it is eating.

Surely, a fly feeding is pure instinct. It responds to cues (smell much more than sight I should think given the fly's compound eye {perhaps excellent for spotting movement, but – identifying potential meals?}, and the likely distance away that food might be found) to approach some material (without thinking, 'oh good, that smells like food!') and then further cues (greater intensity of the smell, perhaps; texture underfoot?) trigger eating, or egg laying. To be honest, I think even as a human I have sometimes behaved this way myself when distracted by a problem occupying all my conscious attention! (To clarify, that's when eating, not laying eggs.)

I do not think flies or beetles have any concept of 'babies'. I am pretty sure they do not know that egg laying is a reproductive function (even if they can be said to have any awareness that they are laying eggs), and will lead to offspring. I'm also pretty sure they are not aware of the issue of infant mortality, and that that they have a greater chance to be a grandparent if they choose the right place to lay their eggs.

  • The plant is deceiving the insects, it's basically saying 'I'm, mimicking the food, come and stay'.

Again, the plant is not saying anything. If does not have a notion of mimicry, and is not aware it is mimic. It does not have any notions. It is not deliberately deceiving the flies or beetles. It does not know there are flies or beetles in the world. It does not do anything deliberately.

I am not even sure it is right to say the plant deceives. You can only deceive an entity capable of being deceived. Insects are not deceived, just following instincts. The plant does not do anything to deliberately attract or entice the insects – their attraction to the plant is just a consequence of a match of the animal's instincts (not under the control of the insect), and the plant's evolved anatomy, physiology and biochemistry.

Now, as I suggested above, I am pretty sure Dr Byers knows all this (much better than me!) Perhaps this is just a habitual way of talking she has adopted to discuss her work, or perhaps she was deliberately using figurative language on this occasion to help communicate the science to a diverse radio audience. To 'make the unfamiliar familiar' the abstract concepts of science need to be related to more familiar everyday experiences. The narrative here helps to humanise science.

Read about 'making the unfamiliar familiar' in teaching

Dr Byers is not alone in this way of presenting science – it is very common when scientists talk to general audiences (e.g., so, no, vegetarians bees did not realise they were missing out on a potential food source and so decide to start eating meat).

Anthropomorphism and teleology

This type of figurative language is anthropomorphic. That is, it treats non-humans (flowers, whole plants, insects, clouds, atoms…) as if they were human – with human cognition (concepts, deliberate conscious thinking) and motivations and emotions. Humans are part of the natural world, and the extent to which anthropomorphism distorts scientific accounts surely varies. An atom cannot be jealous. Nor a bacterium. But I would think a chimp can be.5 What about a fish?

This is a serious issue for science educators because learners often use anthropomorphic language in science lessons, and it is less clear they are doing so figuratively. They may mean this literally – and even if not, may come to habitually use this kind of language and so feel that in doing so they really they can explain phenomena 'scientifically'. But from a technical scientific perspective these are only pseudo-explanations (Taber & Watts, 2000).

Read about the types of pseudo-explanations learners commonly offer

So, sodium reacts with chlorine because the atoms want to fill their shells (Taber & Watts, 1996). So wrong, on so many levels, but so many students think that is the scientific account! Bacteria want to infect us, and seek to become resistant to antibiotics. And so many more examples.

Read about anthropomorphism in students' thinking

Read examples of anthropomorphic explanations in science

The canonical biological explanation is that living things are the way they are because they have evolved to be so, through natural selection. It is natural selection that has led to insects laying eggs in conditions where they are likely to hatch – such as in rotting meat. It is natural selection that has led to some plants attracting insect pollinators by becoming similar to rotting meat – similar, that is, in how those plants are perceived within the insect's unwelt.

But lay people often tend to prefer teleological explanations because they appeal more to our own instincts. It seems that things are the way they are for a purpose: as if a plant was guided towards a new structure because there is an end point, identified from the outset, of becoming attractive to insects that will fertilise the flowers.

As humans behave deliberately and work towards goals, it is easy to transfer this familiar scheme to non-human species. Because human artefacts (the Eiffel Tower, the Pyramids, the iPhone, the international space station) have been designed and built with purposes in mind, it is easy to also see the intricate and effective structures and mechanisms of the living world as also designed with purpose in mind.

Read about teleology

Of course, some of these biological structures can seem so unlikely to have evolved through 'chance' or 'trial and error' that many people find the canonical scientific account non-feasible. (And, it is very hard for people to conceptualise the sheer number of generations over which species have evolved.) Of course, although chance is involved, at each step there is feedback into the system: there is preferential selection of some outcomes. What 'works' is selected not so much because it works, but by virtual of it working.

Evolution is contingent – natural selection can only select the features that are 'in play' at a particular time. But which features remain in play is not just down to chance. 6 So, to adopt an analogy, natural selection is not simply a matter of chance, like a number coming up on a roulette wheel. It is more like a game of poker where the cards dealt may be at random, but one can then select which cards to keep, to build up a winning hand. 7

Darwin's book on 'various contrivances'

Darwin was very aware of this general problem, and the specific example of how it came to be that some plants need to be fertilised in very particular ways, by particular insects – and would seem to have structures so specific and well matched to their pollinators that it seems incredible they could have evolved rather than had been deliberately designed.

Darwin knew that many people found his account of evolution unconvincing in the face of the subtlety and intricacies of natural forms. He chose to study the orchids in some detail because they showed great diversity in flower structures and often seemed especially well 'designed' (with 'various contrivances') for their particular animal fertilisers. Darwin argued that all these odd structures could be understood to have slowly evolved from a common ancestor plant by myriad small modification of ancestral structures that collectively led to the wide diversification of forms (Darwin, 1862)

A difficult balance for science communicators

So, science communicators – whether teachers or journalists or scientists themselves – have a challenge here. The kind of language that is most likely to engage an audience and make science seem accessible can actually come to stand in the way of genuine understanding of the scientific principles.

I do not think that means figurative language should be completely avoided in discussing science, but it is very important to remember that an account which is intended to obviously be metaphorical may be understood literally because anthropomorphism and teleology seem to make perfectly good sense to most people.

These kinds of pseudo-explanations may not score any credit in science exams, but this way of thinking is perhaps as instinctively appealing to many humans as, say, laying eggs in rotting meat is to some insects.

Work cited:
  • Darwin, C. (1862) On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. London: John Murray
  • Plato (2008) Timaeus and Critias (Translator: Robin Waterfield).Oxford University Press, 2008.
  • Taber, K. S. and Watts, M. (1996) The secret life of the chemical bond: students' anthropomorphic and animistic references to bonding, International Journal of Science Education, 18 (5), pp.557-568. (Download this paper)
  • Taber, K. S., & Watts, M. (2000). Learners' explanations for chemical phenomena. Chemistry Education: Research and Practice in Europe, 1(3), 329-353. (Download this paper)

Notes:

1 The enticing episode description is:

"The plant Rafflesia has the world's largest flowers and gives off one of the worst scents; it's also something of a biological enigma, a leafless parasite that lives off forest vines. For the botanist Chris Thorogood, an expert in parasitic and carnivorous plants at the Oxford Botanic Garden and Arboretum, Rafflesia is also an obsession. In his book, Pathless Forest, he goes in search of this mysterious plant in some of the last wildernesses in South East Asia.

Dr Kelsey Byers is an evolutionary chemical ecologist who specialises in floral scent and its influence on the evolution of flowering plants. In her laboratory at the John Innes Centre in Norwich she studies how flowers use different smells to attract their pollinator of choice. From sweet aromas to the stink of rotting flesh, she explores how plants use con-artistry and sexual deception to thrive.

The ethnobotanist William Milliken from Kew Gardens has spent much of his career working with indigenous people in the Amazon to preserve traditional plant knowledge. Now he's focused on collecting folklore about the use of plants to treat ailments in animals in Britain. From wild garlic treating mastitis in cows, to cabbage for flatulence in dogs, he hopes to uncover a cornucopia of plant-based veterinary medicines."

https://www.bbc.co.uk/sounds/play/m001wxkb

2 Dr Thorogood helpfully explained that what Amorphophallus titanum actually means is 'giant distorted penis'.

Does a sunflower have large flowers?

3 Some plants have a great many flowers on the same 'head' or inflorescence. Consider the sunflower. From a distance it seems each of the flowers are large, but, on closer inspection, each inflorescence has a great many tiny individual flowers – each one able to produce pollen and be fertilised.

Photograph of bee on sunflower
A bee on a sunflower collecting nectar and pollen. Each of the tiny structures is an individual flower.

A photo-essay showing sunflowers at different stages of development including close-ups of the structures can be seen here.

4 Although, to be fair, he went on to suggest that a plant "is aware only of the pleasures and pains that accompany its appetites". I would suggest, not.

5 Am I over-cautious? We assume all normal humans beings can potentially feel anger, jealousy, love, fear, etc. But actually no one really knows if anyone else has the same subjective experiences when two people report they are envious, or in love. People could be experiencing something quite different and still using the same label. (This is the qualia issue – e.g., how do I know if the experience I have of red is what you experience? This is something quite different from agreeing on which objects are red.) After all, some people find odours and flavours attractive that others find unpleasant, and the same mode of tickling can lead to quite different responses from different patients.

I think a dog could be sad, and a rabbit can be scared. But I doubt [sic, I mean really doubt] an earthworm could be proud. Unless we can decide where to draw the lines, we really have to wonder if these terms meaningfully transfer across species.

6 At the level of an individual's survival and reproduction, there is a lot of chance involved. Being in the right, or wrong, place when a mate, or a predator, appears; or when a flood, or a forest fire, happens, may have little to do with the variations in features within a population. But a slight advantage in attracting the mate or escaping the peril means that over a large population, across many generations, some features will be preferentially passed on.

7 Strictly these processes are not random, but 'near enough' for human purposes. A roulette ball is large enough to be a classical object (that is we can ignore the indeterminacy that seems to be part of quantum mechanics) so given the spin of the wheel, and the initial trajectory and entry point of the ball (and such factors as the fiction produced due to the materials involved) it is in principle possible to consider this a deterministic process. That is, particular, precise, starting conditions will lead to distinct, in principle predictable, outcomes. In practice though, no human could control the wheel and ball precisely enough to manufacture a specific outcome. It may as well not be deterministic.

Much the same is true of a pack of cards. Given the original order of the deck and a finite number of specific moves to shuffle the deck, only one new order is possible. It is however again difficult to deliberately shuffle a deck and control the new order (though perhaps not quite impossible – which is why often the person shuffling the deck invites other players to choose cuts within the process).

Sometimes in research, the methodology adopted requires randomisation (for example of individual participants to different experimental conditions) and usually such process as rolling dice or drawing blind ballots are 'good enough' even if not strictly random, as no person could control the outcomes obtained.

Read about the criterion for randomisation in research

The baby monitor in your brain

Are our neural systems designed?

Keith S. Taber

Taking advantage of good design? (Image by Ben Kerckx from Pixabay )

"A lot of researchers talk about this [neural system] called the care-giving system which is designed to help us care for our crying babies".

Assoc. Prof. Sara Konrath

The reference to the 'design' of a human neural system caught my attention. The reference was made by Dr Sara Konrath, Associate Professor of Philanthropic Studies at the Lilly Family School of Philanthropy at Indiana University, who was interviewed for the BBC radio programme 'The Anatomy of Kindness'.

As a scientist, I found the reference to 'design' out of place, as it is a term that would often be avoided in a scientific account.

A BBC radio programme and podcast

Design in nature

Mention of 'design' in the context of natural phenomena is of note because of the history of the idea, and its role in key philosophical questions (such as the nature of the world, the purpose of our lives, the origins of good and evil, and other such trifling matters).

The notion of design was very important in natural theology, which looked at 'the book of nature' as God's works, and as offering insight into God as creator. A key argument was that the intricacy of nature, and the way life seemed to encompass such complex interlinked systems that perfectly fitted together into an overarching ecology, could only be explained in terms of a designer who was the careful architect of the whole creation.

Perhaps the most famous example of this argument was that of William Paley who wrote an entire book (1802) making the case with a vast range of examples. He started with the now famous analogy of someone who found a pocket watch on crossing a heath. Had he kicked a stone on his trip, he would have thought little of how the stone came to be there – but a watch was a complex mechanism requiring a large number of intricate parts that had to be just the right size, made of the right kind of materials, and put together in just the right way to function. No reasonable person could imagine the watch had just happened to come about by chance events, and so, by a similar argument, how could anything as subtle and complex as a human body have just emerged by accident and not have been designed by some great intelligence?

If you came across this object lying on the ground, what might you infer? (Image by anncapictures from Pixabay)

Paley's book does a wonderful job of arguing the case, and, even if some of the examples look naive from two centuries on, it was the work of someone who knew a great deal about anatomy, and the natural history of his time, and knew how to build up 'one long argument'. 1 It must have seemed very convincing to many readers at the time (especially as most would have read it from a position of already assuming there was an omniscient and all-powerful creator, and that the types of animals and plants on earth had not substantially changed their forms since their creation).

Indeed, a fair proportion of the world's population would still consider the argument sound and convincing today. That is despite Charles Darwin having suggested, about half a century later, in his own long argument 1 that there was another alternative (than an intelligent designer or simply chance formation of complex organisms and ecosystems). The title of one of Richard Dawkin's most famous books, The Blind Watchmaker (1988), championing the scientific position first developed by Darwin (and Alfred Russel Wallace) is a direct reference to Paley's watch on the heath.

The modern scientific view, supported by a vast amount of evidence from anatomy, genetics, paleontology, geology and other areas is that life evolved on earth over a vast amount of time from common ancestral unicellular organisms (which it is thought themselves evolved from less complex systems over a very long period).

Has science ruled out design?

This does not mean that science has completely ruled out the possibility that modern life-forms could have been designed. Science does rule out the possibility that modern organisms were created 'as is' (i.e., 'as are'), so if they were designed then the designer not only designed their forms, but also the highly complex processes by which they might evolve and the contingencies which made this possible. (That can be seen as an even greater miracle, and even stronger evidence of God's capabilities, of course.) What science does not do is to speculate on first causes which are not open to scientific investigation. 2

Many of the early modern scientists had strong religious convictions – including faith in an intelligent creator – and saw science as work that was totally in keeping with their faith, indeed often as a form of observance: a way of exploring and wondering at God's work. Science, philosophy and theology were often seen as strongly interlinked.

However, the usual expectation today is that science, being the study of nature, has no place for supernatural explanations. Scientists are expected to adopt 'methodological naturalism', which means looking for purely natural mechanisms and causes. 3

Read about science and religion

Arguments from design invoke teleology, the idea that nature has purpose. This makes for lazy science – as we do not need to seek natural mechanisms and explanations if we simply argue that

  • the water molecule was designed to be a shape to form hydrogen bonds, or that
  • copper is a good conductor because its molecular structure was designed for that purpose, or that
  • uranium is subject to radioactive decay because the nucleus of a uranium atom was designed to be unstable

Science has (and so a scientist, when doing her science, should have) nothing to say about the existence of a creator God, and has no view on whether aspects of the natural world might reflect such a creator's design; so arguments from design have no place in scientific accounts and explanations. This is why I honed in on the reference to design.

The evolution of empathy?

The reference was in relation to empathy. The presenter, Dr Claudia Hammond, asked rhetorically "empathy … how did it evolve?", and then introduced an interview clip: "Here's Sara Konrath, Associate Professor at the Lilly Family School of Philanthropy at Indiana University in the U.S." This was followed by Dr Konrath stating:

"A lot of researchers talk about this thing called the care-giving system which is designed to help us care for our crying babies. So, think about a crying baby for a minute that is not your own. You are on an airplane, think about that. [She laughs] And probably what you are hoping for is that baby will stop crying, [Hammond: 'absolutely'], I guess.

We need to have a biological system that will make us feel compassion for that little crying baby and figure out what's wrong so we can make the baby feel better. So, there's a whole neural system that's called the care-giving system, that activates oxytocin which is a hormone that helps us to basically reduce stress and feel close and connected, and as you can imagine that would help us want to change that little nappy or whatever the baby needs. * And that same brain system doesn't seem to distinguish too much, well, you know, we can use that, that same system to care for other people in our lives that we know or even strangers, and even people who are different than us."

Assoc. Prof. Sara Konrath

Now, as pointed out above, accepting evolution (as the vast majority of natural scientists do) does not logically exclude design – but to be consistent it requires the design not only of the intended structure, but also of the entire natural system which will give rise to it. And evolution, a natural process, is open to scientific investigation, whereas claims of design rely on extra-scientific considerations. Moreover, as evolution is an ongoing process, one might suggest that references to 'this stage in the design-realisation process' might be more appropriate.

One way of explaining the apparent inconsistency here ("how did it evolve?"…"designed to help us") is to simply assume that I am being much too literal, as surely Dr Konrath was speaking metaphorically. We can talk about 'the design' of the kidney, or a flower, or of a cow's digestive system, meaning the structure, the layout, the assemblage – without meaning to suggest 'the design' had been designed. Although Dr Konrath referred to the neural system being designed, it is quite possible she was speaking metaphorically.

But can we beleive what we (think we) hear?

A listener can reasonably assume, from the editing of the programme, that Dr Konrath was asked, and was answering, the question 'how did empathy evolve?' Yet this is only implied ("…how did it evolve? Here's Sara Konrath…") – the clip of Dr Konrath does not include any interview questions.

A journalist has to edit a programme together, to offer a narrative a listener can easily follow, so it is likely an interview would be edited down to select the most useful material. Indeed, when transcribing, I suspected that there was an edit at the point I have marked * above. I could not hear any evidence of an edit, BUT to my ears the speech was not natural in moving between "…whatever the baby needs" and "And that same brain system…". Perhaps I am wrong. But, perhaps there was a pause, or a 'false start', edited out to tidy the clip; or perhaps some material deemed less pertinent or too technical for present purposes was removed. Or, possibly, the order of the material has been changed if the speaker had responded to a number of questions, and it was felt a re-ordering of segments of different responses offered a better narrative.

All of that would be totally acceptable, as long as it was done without any intention to distort what the speaker had said. Indeed, in analysing and presenting research material from interviews or written texts, one approach is known as editing. 4 I have used this myself, to select text from different points in an interview to build up a narrative that can summarise an informant's ideas succinctly (e.g., Taber, 2008 5). This needs to be done carefully, but as long as an effort is made to be true to the person's own ideas (as the researcher understands them from the data) and this methodological technique is explicitly reported to readers, it is a valid approach and can be very effective.

Read about approaches to qualitative data analysis

A convincing argument?

Perhaps, if Dr Konrath was indeed asked 'how did empathy evolve?' this was a rather unfair question. Unlike some anatomical structures, empathy does not leave direct evidence in the fossil record. This might explain a not entirely convincing response.

The gist of the clip, as I assume a listener was meant to understand it, was along the lines.

How did empathy evolve?

  • babies cannot look after themselves and need support
  • they cry to get attention when they need help
  • a system evolved to ensure that others around the baby would pay attention to its cries, and feel compassionate, and so help it
  • the system either has the side effect of, or has evolved over time, allowing us to be empathetic more generally so we support people who need help

Perhaps that narrative is correct, and perhaps there is even scientific evidence for it. But, in terms of what I actually hear Dr Konrath say, I do not find a strong evolutionary account, but rather something along the lines:

  • We have a biological system known as the care-giving system, that activates a hormone that reduces stress and helps us feel close and connected to others
  • this allows us to feel compassion for people in need
  • encouraging us to care for other people, largely indiscriminately
  • even strangers, such as a crying baby

When I reframe ('edit') the interview that way, I do not see any strong case for why this system is designed specifically to help us care for our crying babies – but nor is there any obvious evolutionary argument. 6

If one approaches this description with a prior assumption that such things have evolved through natural selection then Dr Konrath's words can certainly be readily interpreted to be consistent with an evolutionary narrative. 6 However, someone who did not accept evolution and had a metaphysical commitment to seeing the natural world as evidence for a designer would surely be able to understand the interview just as well within that frame. I suspect both Paley and Darwin would have been able to work this material into their arguments.

Works cited:
  • Darwin, C. (1859/2006). The Origin of Species. In E. O. Wilson (Ed.), From so Simple a Beginning: The four great books of Charles Darwin. New York: W. W. Norton.
  • Dawkins, R. (1988). The Blind Watchmaker. Harmondsworth, Middlesex: Penguin Books.
  • Paley, W. (1802/2006). Natural Theology: Or Evidence of the Existence and Attributes of the Deity, Collected from the Appearances of Nature (M. D. Eddy & D. Knight Eds.). Oxford: Oxford University Press.
  • Taber, K. S. (2008). Exploring Conceptual Integration in Student Thinking: Evidence from a case study. International Journal of Science Education, 30 (14), 1915-1943. (DOI: 10.1080/09500690701589404.)
  • Taber, K. S. (2013). Conceptual frameworks, metaphysical commitments and worldviews: the challenge of reflecting the relationships between science and religion in science education. In N. Mansour & R. Wegerif (Eds.), Science Education for Diversity: Theory and practice (pp. 151-177). Dordrecht: Springer. [Download manuscript version]

Note:

1 The term 'one long argument' was used by Darwin to describe his thesis in the Origin of Species.

2 I write loosely here: science does not do anything; rather, it is scientists that act. Yet it would not be true to claim scientists do not speculate on first causes which are not open to scientific investigation. Many of them do. (Dawkins, for example, seems very certain there is no creator God.) However, that is because scientists are people and so have multiple identities. Just as nothing stops a scientist also being a mother or a daughter; nothing stops them being ice skaters, break dancers or poets. So, scientists do speculate outside of the natural realm – but then they are doing something other than science, as when they write limericks. (And perhaps something where their scientific credentials suggest no special expertise.)

3 Unfortunately, this can mislead learners into thinking science is atheistic and scientists necessarily atheists:

"The tradition in Western science (with its tendencies towards an analytical and reductionist approach) to precede as though the existence and potential role of God in nature is irrelevant to answering scientific questions, if not explicitly explained to
students, may well give the impression that because science (as a socio-cultural activity) does not need to adopt the hypothesis of the divine, scientists themselves (as individuals sharing membership of various social groups with their identities as scientists) eschew such an idea."

Taber, 2013: 153

4 This process would need to be made explicit in research, where it is normally just accepted as standard practice in journalism. These two activities can be seen as quite similar, especially when research is largely based on reports from various informants. A major difference however is that whereas researchers often have months to collect, analyse and report data, journalists are often expected to move on to the next story or episode within days, so may be working under considerable time pressures.

5 For example,

"Firstly the interview transcript was reworked into a narrative account of the interview based around Alice's verbatim responses, but following the chronology of the interview schedule in the order of the questions….The next stage of the analysis involved reorganising the case material into themes in terms of the main concepts used in Alice's explanations…This process produced a case account that was reduced (in this case to about 1,000 words), and which summarises the ways Alice used ideas in her interview."

Taber, 2008: 1926

6 One can imagine researchers asking themselves how this indiscriminate system for helping others in need arose, and someone suggesting that perhaps it was originally to make sure mothers attended to their own babies, but as a 'false negative' would be so costly (if you do not notice your baby is unfed, or has fallen in the lake, or is playing with the tiger cubs…) the system was over-sensitive and tolerated 'false positives' (leading to people attending to unrelated babes in need), and even got triggered by injured or starving adults – which it transpired increased fitness for the community, so was selected for…

It can be much easier to invent feasible-sounding evolutionary 'just-so stories' than rigorously testing them!

Of opportunistic viruses and meat-eating bees

The birds viruses and the bees do it: Let's do it, let's…evolve

Keith S. Taber

bees that once were vegetarian actually decided to change their ways…

this group of bees realised that there's always animals that are dying and maybe there's enough competition on the flowers [so] they decided to switch

How the vulture bee got its taste for meat

I was struck by two different examples of anthropomorphism that I noticed in the same episode of the BBC's Science in Action radio programme/podcast.

Science in Action episode broadcast 5th December 2021

Anthropomorphism in science?

Anthropomorphism is the name given treating non-human entities as if they were human actors. An example of anthropomorphic language would be "the atom wants to donate an electron so that it can get a full outer shell" (see for example: 'A sodium atom wants to donate its electron to another atom'). In an example such as that, an event that would be explained in terms of concepts such as force and energy in a scientific account (the ionisation of an atom) is instead described as if the atom is a conscious agent that is aware of its status, has preferences, and acts to bring about desired ends.

Read about Anthropomorphism

Of course, an atom is not a complex enough entity to have mental experience that allows it to act deliberately in the world, so why might someone use such language?

  • Perhaps, if the speaker was a young learner, because they have not been taught the science.
  • Perhaps a non-scientist might use such language because they can only make sense of the abstract event in more familiar terms.

But what if the speaker was a scientist – a science teacher or a research scientist?

When fellow professionals (e.g., scientists) talk to each other they may often use a kind of shorthand that is not meant to be taken literally (e.g., 'the molecule wants to be in this configuration') simply because it can shorten and simplify more technical explanations that both parties understand. But when a teacher is talking to learners or a scientist is trying to explain their ideas to the general public, something else may be going on.

Read about Anthropomorphism in public science discourse

Anthropomorphism in science communication and education

In science teaching or science communication (scientists communicating science to the public) there is often a need to present abstract or complex ideas in ways that are accessible to the audience. At one level, teaching is about shifting what is to be taught from being unfamiliar to learners to being familiar, and one way to 'make the unfamiliar familiar' is to show it is in some sense like something already familiar.

Therefore there is much use of simile and analogy, and of telling stories that locate the focal material to be learned within a familiar narrative. Anthropomorphism is often used in this way. Inanimate objects may be said to want or need or try (etc.) as the human audience can relate to what it is to want or need or try.

Such techniques can be very useful to introduce novel ideas or phenomena in ways that are accessible and/or memorable ('weak anthropomorphism'). However, sometimes the person receiving these accounts may not appreciate their figurative nature as pedagogic / communicative aids, and may mistake what is meant to be no more than a starting point, a way into a new topic or idea, as being the scientific account itself. That is, these familiarisation techniques can work so well that the listener (or reader) may feel satisfied with them as explanatory accounts ('strong anthropomorphism').

Evolution – it's just natural (selection)

A particular issue arises with evolution, when often science only has hypothetical or incomplete accounts of how and why specific features or traits have been selected for in evolution. It is common for evolution to be misunderstood teleologically – that is, as if evolution was purposeful and nature has specific end-points in mind.

Read about teleology

The scientific account of evolution is natural selection, where none of genes, individual specimens, populations or species are considered to be deliberately driving evolution in particular directions (present company excepted perhaps – as humans are aware of evolutionary processes, and may be making some decisions with a view to the long-term future). 1

Yet describing evolutionary change in accord with the scientific account tends to need complex and convoluted language (Taber, 2017). Teleological and anthropomorphic shorthand is easier to comprehend – even if it puts a burden on the communicatee to translate the narrative into a more technical account.

What the virus tries to do

The first example from the recent Science in Action episode related to the COVID pandemic, and the omicron variant of the SARS-CoV-2 virus. This was the lead story on the broadcast/podcast, in particular how the travel ban imposed on Southern Africa (a case of putting the lid on the Petri dish after the variant had bolted?) was disrupting supplies of materials needed to address the pandemic in the countries concerned.

This was followed by a related item:

"Omicron contains many more mutations than previous variants. However scientists have produced models in the past which can help us understand what these mutations do. Rockefeller University virologist Theodora Hatziioannou produced one very similar to Omicron and she tells us why the similarities are cause for concern."

https://www.bbc.co.uk/programmes/w3ct1l4p

During this item, Dr Theodora Hatziioannou noted:

"When you give the virus the opportunity to infect so many people, then of course it is going to try not only every possible mutation, but every possible combination of mutations, until it finds one that really helps it overcome our defences."

Dr Theodora Hatziioannou interviewed on Science in Action

Dr Theodora Hatziioannou
Research Associate Professor
Laboratory of Retrovirology
The Rockefeller University

I am pretty sure that Dr Hatziioannou does not actually think that 'the virus' (which of course is composed of myriad discrete virus particles) is trying out different mutations intending to stop once it finds one which will overcome human defences. I would also be fairly confident that in making this claim she was not intending her listeners to understand that the virus had a deliberate strategy and was systematically working its way through a plan of action. A scientifically literature person should readily interpret the comments in a natural selection framework (e.g., 'random' variation, fitness, differential reproduction). In a sense, Dr Hatziioannou's comments may be seen as an anthropomorphic analogy – presenting the 'behaviour' of the virus (collectively) by analogy with human behavior.

Yet, as a science educator, such comments attract my attention as I am well aware that school age learners and some adult non-scientists may well understand evolution to work this way. Alternative conceptions of natural selection are very common. Even when students have been taught about natural selection they may misunderstand the process as Lamarckian (the inheritance of acquired characteristics – see for example 'The brain thinks: grow more fur'). So, I wonder how different members of the public hearing this interview will understand Dr Hatziioannou's analogy.

Even before COVID-19 came along, there was a tendency for scientists to describe viruses in such terms as as 'smart', 'clever' and 'sneaky' (e.g., 'So who's not a clever little virus then?'). The COVID pandemic seems to have unleashed a (metaphorical) pandemic of public comments about what the virus wants, and what it tries to achieve, and so forth. When a research scientist talks this way, I am fairly sure it is intended as figurative language. I am much less sure when, for example, I hear a politician telling the public that the virus likes cold weather ('What COVID really likes').

Vulture bees have the guts for it

The other item that struck me concerned vulture bees.

"Laura Figueroa from University of Massachusetts in Amhert [sic] in the US, has been investigating bees' digestive systems. Though these are not conventional honey bees, they are Costa Rican vulture bees. They feed on rotting meat, but still produce honey."

https://www.bbc.co.uk/programmes/w3ct1l4p
Bees do not actually make reasoned choices about their diets
(Original image by Oldiefan from Pixabay)

The background is that although bees are considered (so I learned) to have evolved from wasps, and to all have become vegetarians, there are a few groups of bees that have reverted to the more primitive habits of eating meat. To be fair to them, these bees are not cutting down the forests to set up pasture and manage livestock, but rather take advantage of the availability of dead animals in their environment as a source of protein.

These vulture bees (or carrion bees) are able to do this because their gut microbiomes consist of a mix of microbes that can support them in digesting meat, allowing them to be omnivores. This raises the usual kind of 'chicken and egg' question 1 thrown up by evolutionary developments: how did vegetarian bees manage to shift their diet: the more recently acquired microbes would not have been useful or well-resourced whilst the bees were still limiting themselves to a plant-based diet, but the vegetarian bees would not have been able to digest carrion before their microbiomes changed.

As part of the interview, Dr Figueroa explaied:

"These are more specialised bees that once they were vegetarian for a really long time and they actually decided to change their ways, there's all of this meat in the forest, why not take advantage? I find that super-fascinating as well, because how do these shifts happen?

Because the bees, really when we are thinking about them, they've got access to this incredible resource of all of the flowering plants that are all over the world, so then why switch? Why make this change?

Over evolutionary time there are these mutations, and, you know, maybe they'd have got an inkling for meat, it's hard to know how exactly that happened, but really because it is a constant resource in the forest, there's always, you know, this might sound a little morbid but there's always animals that are dying and there's always this turn over of nutrients that can happen, and so potentially this specialised group of bees realised that, and maybe there's enough competition on the flowers that they decided to switch. Or, they didn't decide, but it happened over evolutionary time.

Dr Laura Figueroa interviewed on Science in Action

Dr Figueroa does not know exactly how this happened – more research is needed. I am sure Dr Figueroa does not think the bees decided to change their ways in the way that a person might decide to change their ways – perhaps deciding to get more exercise and go to bed earlier for the sake of their health. I am also sure Dr Figueroa does not think the bees realised that there was so much competition feeding on the flowers that it might be in their interests to consider a change of diet, in the way that a person might decide to change strategy based on an evaluation of the competition. These are anthropomorphic figures of speech.

Dr Laura Figueroa, NSF Postdoctoral Research Fellow in Biology
Department of Entomology, Cornell University / University of Massachusetts in Amherst

As she said "they didn't decide, but it happened over evolutionary time". Yet it seems so natural to use that kind of language, that is to frame the account in a narrative that makes sense in terms of how people experience their lives.

Again, the scientifically literate should appreciate the figurative use of language for what it is, and it is difficult to offer an accessible account without presenting evolutionary change as purposive and the result of deliberation and strategy. Yet, I cannot help wondering if this kind of language may reinforce some listeners' alternative conceptions about how natural selection works.

Work cited:
Notes

1 The 'selfish' gene made famous by Dawkins (1976/1989) is not really selfish in the sense a person might be – rather this was an analogy which helped shift attention from changes at the individual or species level when trying to understand how evolution occurs, to changes in the level of distinct genes. If a mutation in a specific gene leads to a change in the carrying organism that (in turn) leads to that specimen having greater fitness then the gene itself has an increased chance of being replicated. So, from the perspective of focusing on the genes, the change at the species level can be seen as a side effect of the 'evolution' of the gene. The gene may be said to be (metaphorically) selfish because it does not change for the benefit of the organism, but to increase its own chances of being replicated. Of course, that is also an anthropomorphic narrative – actually the gene does not deliberately mutate, has no purpose, has no notion of replication, indeed, does not even 'know' it is a gene, and so forth.

2 Such either/or questions can be understood as posing false dichotomies (here, either the bees completely changed their diets before their microbiomes or their microbiomes changed dramatically before their diets shifted) when what often seems most likely is that change has been slow and gradual.

Opposites avoid attracting

Do species become more different from one another to avoid breeding?

Keith S. Taber

A tamarin monkey
A different tamarin

They say "opposites attract". True perhaps for magnetic poles and electrical charges, but the aphorism is usually applied to romantic couples. It seems like one of those sayings that survives due to the 'confirmation bias' in human cognition. That is, as long as from time to time seemingly unlikely couplings occur, the explanation that 'opposites attract' seems to have some merit, even in it only applies to a minority of cases.

Trying to avoid a fight

What got me thinking about this was an interview (on BBC's Inside Science radio programme/podcast) with Dr Jacob Dunn, Associate Professor in Evolutionary Biology at Anglia Ruskin University, who studies primate vocal communication. He was discussing his research into the calls of tamarin monkeys in the Amazon rainforest, and in particular the calls of two different species where their ranges overlap.

Apparently, in the area of overlap the red-handed tamarins seemed to have adapted one of their calls so it sounds very similar to that of the pied tamarins. (N.b. The images above represent two contrasting species, just as an illustration.) The suggested explanation was that this modification made it more likely that the monkeys of different types would recognise each other's calls – in particular that "…they are trying to be understood, so they don't end up in a fight…".

Anthropomorphism?

I wondered if these monkeys were really "trying" to achieve this, or whether this might be an anthropomorphism. That is, were the red-handed tamarins deliberately changing their call in this way in order to ensure they could be understood – or was this actually natural selection in operation – where, because there was an advantage to cross-species communication (and there will be a spread of call characteristics in any population), over time calls that could be understood by monkeys of both species would be selected for in a shared niche.

Then again, primates are fairly intelligent creatures, so perhaps Dr Dunn (who, unlike me is an evolutionary biologist) means this literally, and this is something deliberate. Certainly, if the individual monkeys are shifting their calls over time in response to environmental cues, rather than the shift just occurring across generations, then that would seem to suggest this is learning rather than evolution. (Of course, it could be implicit learning based on feedback from the responses to their behavior, and still may not be the monkeys consciously adopting a strategy to be better understood.)

Becoming more distinct

Dr Dunn's explanation of the wider issue of how similar animals will compete for scarce resources intrigued me:

"When you have species that are closely related to one another and live in sort of overlapping areas there's quite a lot of pressure because they're likely to be competing for key resources. So, sometimes we see that these species actually diverge in their traits, they become more different from one another. Examples of that are sort of coloration and the way that animals look. Quite often they become more distinct than you would expect them to, to avoid breeding [sic] with one another."

My initial reaction to this was to wonder why the two species of monkeys needed to avoid breeding with each other. 'Breeding' normally refers to producing offspring, reproduction, but usually breeding is not possible across species (except sometimes to produce infertile hybrids).

Presumably, all tamarins descended from a common ancestor species. Speciation may have occurred when different populations become physically separated and so were no longer able to inter-breed (although still initially sexually compatible) simply because members of the two groups never encountered each other. Over time (i.e., many generations) the two populations might then diverge in various traits because of different selection pressures in the two different locations, or simply by chance effects* which would lead to the two gene pools drifting in different ways.

(* Read about 'Intergenerational couplings in the family: A thought experiment about ancestry')

Two groups that had formed separate species such that members of the two different species are no longer able to mate to produce fertile offspring, might subsequently come to encounter each other again (e.g., members of one species migrating into to the territory of the other) but inter-breeding would no longer be possible. A further mechanism to avoid breeding (by further "diverge[nce] in their traits") would not seem to make any difference.

If they actually cannot breed, there is no need to avoid breeding.

A breeding euphemism?

However, perhaps 'breeding' was being used by Dr Dunn as a euphemism (this was after all a family-friendly radio programme broadcast in the afternoon), as a polite way of saying this might avoid the moneys copulating with genetically incompatible partners – tamarins of another species. As tamarins presumably do not themselves have a formal biological species concept, they will not avoid coupling with an animal from a different species on the grounds that they cannot breed and so it would be ineffective. They indulge in sexual activity in response to instinctive drives, rather than in response to deliberate family planning decisions. That is, we might safely assume these couplings are about sexual attraction rather than a desire to have children.

I think that was what Jürgen Habermas may have meant when he wrote that:

"…the reproduction of every individual organism seems to warrant the assumption of purposiveness without purposeful activity…"

In terms of fitness, an animal is clearly more likely to have offspring if it is attracted to a sexually comparable partner than a non-compatible one. Breeding is clearly important for the survival of the species, and uses precious resources. Matings that could not lead to pregnancy (or, perhaps worse from a resource perspective, might lead to infertile hybrids that need to be nurtured but then fail to produce 'grandchildren'), would reduce breeding success overall in the populations. Assuming that a tamarin is more likely to be attracted to a member of a different species when it does not look so different from its own kind, it is those monkeys in the two groups that look most alike who are likely to be inadvertently sharing intimate moments with biologically incompatible partners.

A teleological explanation

Dr Dunn's suggestion that "quite often [the two species] become more distinct than you would expect them to, to avoid breeding with one another" sounds like teleology. That is, it seems to imply that there is a purpose (to avoid inter-breeding) and the "species actually diverge in their traits" in order to bring about this goal. This would be a teleological explanation.

(Read about 'Teleology')

I suspect the actual explanation is not that the two species "come more distinct…to avoid breeding with one another" but rather than they come more distinct because they cannot breed with each other, and so there is a selection advantage favouring the most distinct members of the two different species (if they are indeed less likely than their less distinguishable conspecifics to couple with allospecific mates).

I also suspect that Dr Dunn does not actually subscribe to the teleological argument, but is using a common way of talking that biologists often adopt as a kind of abbreviated argument: biologists know that when they refer to evolution having a purpose (e.g., to avoid cross-breeding), that is only a figure of speech.

Comprehension versus accuracy?

However, I am not sure that is always so obvious to non-specialists listening to them. Learners often find natural selection a challenging topic, and many would be quite happy with accepting that adaptations may have a purpose (rather than just a consequence). This reflects a common challenge of communicating science – either in formal teaching or supporting public understanding.

The teacher or science communicator simplifies accounts and uses everyday ways of expressing ideas that an audience without specialist knowledge can readily engage with to help 'make the unfamiliar familiar'. However, the simplifications and approximations and short-cuts we use to make sure what is said can be understood (i.e., made sense of) by non-specialists also risks us being misunderstood.

Intergenerational couplings in the family

A thought experiment about ancestry

Keith S. Taber

(An 'out-take' from 'The Nature of the Chemical Concept', Taber, 2019*)

It would seem (rightly) indecent for your great great grandfather to have procreated with your sister – but if you could go back far enough in your family tree you would surely find even more extreme examples of intergenerational couplings!

Skulls images by Parker_West from Pixabay

Some approaches to conceptualising speciation may by definition impose sharp distinctions: in one version of cladistics it is assumed that at any speciation event the ancestor species ceases to be extant, and the new species comes into existence at one moment in time – if members of (what was) the ancestral species happily carry on living their lives despite this conventional extinction, as a new species branches off from the ancestral line, they are judged now to be members of another new species. That is, in this system a species is never considered to give rise to a new species and also continue, but rather transitions into two new species, even if one contains individuals indistinguishable from those in the ancestral line (LaPorte 2004). However, I am going to take the position here that if experts in the field cannot distinguish specimens as being from different species then it is reasonable to consider those specimens as conspecific.

To take an example close to home, consider the species Homo sapiens. Every human alive today had parents who were, like themselves, specimens of the species Homo sapiens. These parents also had parents who were specimens of the species Homo sapiens. So did their parents – and (to avoid this text becoming extremely tedious) so on, through a large number of generations. However, modern humans are understood to have evolved from earlier hominids (who in turn evolved from non-human primates, who evolved from non-primate mammals, who evolved from non-mammalian chordates, and so forth.)

A thought experiment about ancestry

So, consider a thought experiment where scientists had physical evidence of the full ancestry of someone, some specimen of Homo sapiens, alive today – bones, DNA, whatever. It is only a thought experiment, so it only has to be possible in principle, not feasible in practice. And forensic science today achieves things that might have seemed fantastic just a few decades ago – so who can say what might become feasible in time?

Experts in anatomy or genetics would agree that the generation of the parents of our human friend were Homo sapiens, as were the previous generation, and the generation before that, and… However, at some point many, many generations back, the experts would agree that the scientific evidence showed these more distant ancestors were not Homo sapiens, but something else – perhaps Homo heidelbergensis.

We would be going back something of the order of tens of thousands of generations. Perhaps (for the sake of this thought experiment – the actual numbers are not critical to the argument) all the experts agree that the ancestors in generation n-14000 (n minus fourteen thousand, where n is the current generation, our living person) were members of our species, Homo sapiens, and perhaps these experts also all agree that the ancestors in generation n-17000 were a different species, not Homo sapiens: but where does this transition occur?

It seems unlikely that the experts would be able to agree, based on clear distinctions in the material evidence (even if we assumed the evidence available, as this is a thought experiment), that ancestors in generation n-15777 (for example) were the earliest ancestors who were members of Homo sapiens and that the ancestors in generation n-15778 were members of a different species.

Gradual change

This is not simply unlikely because the experts would not agree as some would be more expert than others, and so be more likely to get things right: it is simply that the distinctions between species are not sudden and abrupt, but occur over time. Those transitions may often appear rapid when looking at the geological record, in terms of what is sometimes called 'deep time', but even allowing that evolution may not be as gradual and even as was once widely considered (Gould and Eldredge 1993/2000), the shift between distinct species is gradual in terms of our experience of the natural world. Our lives occupy a tiny period in the vastness of the history of the biota on Earth, so we experience the living things in our environment as if a single cross-section of a cone of biological development.

We are in effect living upon one cross-section, one microtome slice as it were, of deep-time – and so species appear as discrete kinds (Figure from Taber, 2013/2017.)
A compromised geometric progression?

Before moving on, it is worth highlighting the absurdity of extrapolating what seems commonplace on a 'local' (temporal) scale to a geological scale. Most people have 2 (21) parents, who were probably alive at the same time (i.e., their lives must have overlapped for them to be parents, unless there was some cryogenic storage of sperm or eggs – something that is now possible and means a very small proportion of people alive today have been conceived at a time when only one biological parent was alive), and 4 (22) grandparents whose lives nearly always overlapped in time, and 8 (23) great-grandparents whose lives probably overlapped in time… We might be tempted to generalise to having 2n ancestors if we go back n generations.

This pattern does not necessarily repeat indefinitely however. So, the British Head of State, at the time of writing, is Queen Elizabeth II. Two of her great-great grandparents were Queen Victoria and her escort Prince Albert. Elizabeth is married to Prince Philip. Two of his great-great grandparents were (also) Queen Victoria and Prince Albert. The Children of the current Queen (Charles, Anne, Andrew and Edward) therefore do not have a full, unique set of great-great-great grandparents, as Victoria and Albert each occupy positions on their family tree that could in principle have been filled by two different people (although that of course, would not have given rise to the existence of the particular individuals Charles, Anne, Andrew and Edward who are alive today).

It is a common view that the degree of inbreeding among the royal houses of Europe was responsible for the instances of certain medical conditions among the royals. Indeed, haemophilia was referred to as 'the royal disease'

Finding a mate

Although marriage and breeding within the extended family has been particularly noted among royalty, it was by no means their exclusive practice. In highly stratified societies where marrying above or below one's supposed rank was not acceptable, the range of potential mates in one's social circle might be very limited (as reflected in novels of the likes of Jane Austen).

Marrying relatives who were not immediate family was common and often productive. Charles Darwin married a cousin, Emma Wedgewood, which led to a very happy marriage, and some highly achieving offspring. Charles and Emma shared a grandfather – Josiah Wedgwood (the famous potter) – and grandmother. Social circle and extended family could overlap considerably.

A trivia quiz question might be:

How was John Allen Wedgwood able to legally marry two of his cousins on the same day? **

For much of human pre-history people lived in small groups where the range of potential mates would have been severely limited, leaving aside questions of social status. Indeed it is possible that the common taboo on sexual relations with very close relatives, i.e. incest, developed in a context where the number of feasible candidates for a mate was often very small.

A paradox? You have more human ancestors than the number of people who have ever lived

Returning, then, to our thought experiment. If each of their theoretical possible ancestors in generation n-15777 were discrete, individual, specimens (of whatever species) then our contemporary subject would have 215777 ancestors in that generation. That is a number vastly greater that the number of people living today (which is less than 233) or indeed who have ever existed – and is even vastly greater than estimates of the number of particles in the whole universe! (One estimate for the total number of quarks plus electrons is 'only' around 2268.) Some estimates for the size of the early Homo sapiens population are around 214 – rather less than 215777!

The vast discrepancy here then comes from assuming that the number of ancestors doubles in each generation. Most people have two parents, four grandparents, and eight great grandparents – but if one goes back a large number of generations there must have been considerable redundancy in the sense of individual ancestors taking up a number of positions on one's personal family tree. And we cannot even assume these multiple roles fall within the same generation.

The notion that anyone alive today would have all their ancestors from generation n-15777 alive at the same time is unreasonable.

If we assume that through most of human history the time lapse between generations was largely in a range 15-25 years (and clearly there will have been plenty of children born to parents younger than 15 and older than 25, so this is a conservative range) then it becomes obvious that at the time when one of our ancestors in generation n-15777 was alive, so were many of our ancestors in a wide range of other generations.

If the mean gap between generations was 20 years, then 15 777 generations ago was about 315 540 years ago. At the same time a line of descent with an average gap between generations of 15 years would be a little more than 21 036 generations ago, and a line of descent with an average gap between generations of 25 years would be 12 622 generations ago.

A schematic representation of the distribution of a person's ancestors living c.316 000 years ago in terms of how many generations separate them from that person. Many (most) ancestors will be represented many times (by different lines of descent) across a spread of points in the distribution.

It may seem strange to think that some of the ancestral pairings that led to us were between individuals that from our (temporally reversed) perspective were in generations that were hundreds or perhaps even thousands apart***: but of course the point is they were alive at the same time.

A highly simplified scheme showing descent along only two lines. Using the simplified example that people are born when their mother is 18 but their father is 24 (clearly there will normally be much variation in any 'branch' of any 'tree') it does not take many generations before ancestors alive (and of reproductive age) at the same time can be considered to be from different generations.*** Bearing in mind that we all have far fewer direct ancestors than potentially unique places on the 'tree', we could in principle trace many of our ancestors through multiple routes relating to different generations. In this simplified scheme the person's father's father's father is also their mother's mother's mother's father. So the same person could be your great-grandfather and also your great-great-grandfather. M = mother; FF = father's father; MMMF = mother's mother's mother's father, etc.
You are a member of the 15 778th generation of Homo sapiens, and you are a member of the 15 779th generation of Homo sapiens, and you are a member of the 15 777th generation of Homo sapiens, and…

By the same (or, if you prefer, the reverse) logic, even if we were (adopting a cladistic approach) able to pinpoint a precise moment in time when Homo sapiens appeared, generation 'Homo sapiens 1', then a person alive today would not by comparison be unequivocally in generation 'Homo sapiens 15778' (or whatever), at least, not unless we adopted a convention to count down through a particular line (e.g., always the mother). Rather, they would be in a hybrid generation with a wide range, say generation 'Homo sapiens 11 246-to-19 975', or whatever.

As a final observation, a common definition of species refers to breeding populations that can produce viable (fertile) offspring. If the distinction between Homo sapiens and, say Homo heidelbergensis, is a gradual shift and not a sharp cut off, then the question of interbreeding between co-existing species is somewhat avoided: but there is much evidence that our ancestors interbred with Neanderthals, even though they are traditionally considered to be a distinct species (Homo neanderthalensis).

Waking up a different species

So the biological species concept, whilst being extremely useful in science, would seem to either be somewhat arbitrary (if we adopt a cladistics perspective, and just define by fiat specific speciation events at which point old species become extinct and new ones are said to come into existence), or to have rather fuzzy edges.

The cladistic perspective keeps things rather nice and tidy but it would seem a bit like living in Europe during the restoration, when a person could go to bed an orthodox believer and wake up the next day a heretic because the sovereign had decided to switch the National faith from Catholicism to Protestantism (or vice versa). The person had not changed, but the definitions had. A helpful perspective, perhaps, is to treat the notion of biological species as a scientific hypothesis (Knapp 2017), in that when a scientist proposes a species this is a hypothesis about a certain regularity in the natural world: a hypothesis which is then the basis for further investigation.

** The answer does not relate to a tragic wedding-reception death followed by an indecently short whirlwind romance, but rather that the Rev. Wedgwood officiated at the wedding of his cousin Emma to his cousin Charles.

*** Of course, by definition the couple were in the same generation back along the line of descent they shared, but possibly in very different generations back along alternative lines of descent. So, the individual highlighted with the pink circle in the preceding figure has children with two different partners in the ancestral 'tree' (really, a network) as MMMMMMMM mating with MMMMMMMF, and as FFFFFM mating with FFFFFF. In both cases she is the same number of generations back as her partner in terms of their child on the particular ancestral line, BUT she is both a great-great-great-great grandmother and a great-great-great-great-great-great grandmother of the same individual. So in that sense, she belongs to two different generations. That is only considering 'fruitful' couplings that led to an offspring in the direct ancestory of some individual.  There will clearly be many couplings that did not lead to offspring among someone's ancestors (or indeed no offspring at all) where the couple concerned only appear in the ancestral 'tree' of some individual in different generations.

Sources cited:

* When writing 'The Nature of the Chemical Concept' I was discussing the idea of natural kinds in chemistry (for example, 'potassium' has a better claim to refer to a natural kind than 'acid'), and the limitations of the notion of a natural kind. An example that I assumed would be familiar to readers was that of species. Species used to be considered different natural kinds each with their own essence, that were, largely at least, found distinct in nature:

Species as Natural Kinds? A Warning from Biology

"People, not just scientists, tend to naturally (sic, automatically) notice kinds in nature: for example, kinds of mineral, kinds of meteorological conditions (e.g., types of clouds), and perhaps most obviously, kinds of living thing…. When children, we all readily notice and learn that the world contains different kind of living things. There are birds and horses and dogs and fish and so forth. We come to recognise levels of classification without difficulty: this animal is a dog, and also a Labrador; this creature is both a sparrow and a bird. Later, when we study science in school we find that such distinctions are made formally by scientists, although not always in ways that entirely fit with informal everyday use… so mushrooms should not be considered plants, for example.

More advanced study might lead us to realise that the recognition of species and other higher-level taxa is not so straightforward. When I was at school, it was considered that the dinosaurs, the 'terrible lizards', as a group became extinct around 66 million years ago at the time of the formation of the Cretaceous-Paleogene (aka KT, Cretaceous-Tertiary) boundary, but since then 'lizard' has become a questionable category of natural kind, whilst many biologists now claim that birds are technically extant (rather than extinct) dinosaurs.

Having learnt that the main orders of vertebrates were fish, amphibians, reptiles, birds, and mammals, it appears that not only might birds be considered reptiles, but that reptiles are by some biological criteria not actually an essential kind (that is a kind with a particular essence). Even fish are not exempt. Leaving aside the tendency of the term fish to sometimes be used in a vernacular sense of sea creature (to include whales and 'shell-fish' for example), it seems that by some criteria fish do not share a particular essence as a group, as some fish are more closely related to members of other groups than they are to some other fish…. Guinea pigs are no longer seen as members of the mammalian group of rodents. In addition, these are just some examples from the vertebrates, among the most familiar groups of animals to most people….

Modern scientific thinking, post-Darwin, suggests that there are no absolute distinctions between species. Darwin himself thought he had done biology a service in offering the perspective on the biota suggested by his theory of natural selection. Descent of different groups from common ancestors, should (Darwin thought) have brought an end the interminable wrangling about whether particular groups were 'really' different species or actually varieties of the same species. For Darwin, understanding the origin of species suggested there could be no absolute distinct essence of any particular biological grouping such that there would always be an absolute distinction between specimens of one species and another"

Taber, 2019: 121-123

In writing about how the shift between species was a gradual process I went into the ideas about how over a long period of time the number of generations separating two individuals becomes ambiguous and how most of our ancestors must appear multiple times on our 'tree' of descent (which also means that if you go back far enough, most of those alive then, who have offspring alive today, are probably shared ancestors of most of us). However, this was getting somewhat peripheral to my key point about species and natural kinds. So I excised that material, thinking I might find another use for it. That text is reproduced above.

Learning about natural selection and denying evolution

An ironic parallel

Keith S. Taber

Image by Free-Photos from Pixabay 

I was checking some proofs for something I had written today* [Taber, 2017], and was struck by an ironic parallel between one of the challenges for teaching about the scientific theory of evolution by natural selection and one of the arguments put forward by those who deny the theory. The issue concerns the value of having only part of an integrated system.

The challenge of evolutionary change

One of the arguments that has long been made about the feasibility of evolution is that if it occurs by many small random events, it could not lead to progressive increases in complexity – unless it was guided by some sense of design to drive the many small changes towards some substantive new feature of ability. So, for example, birds have adaptations such as feathers that allow them to fly, even though they are thought to have evolved from creatures that could not fly. The argument goes that for a land animal to evolve into a bird there need to be a great many coordinated changes. Feathers would not appear due to a single mutation, but rather must be the result of a long series of small changes. Moreover, simply growing features would not allow an animal to fly without other coordinated changes such as evolving very light bones and changes in anatomy to support the musculature needed to power the wings.  

The same argument can be made about something like the mammalian eye, which can hardly be one random mutation away from an eyeless creature. The eye requires retinal cells, linked to the optic nerve, a lens, the iris, and so on. The eye is an impressive piece of equipment which is as likely to be the result of a handful of random events, as would be – say, a pocket watch found walking on the heath (to use a famous example). A person finding a watch would not assume its mechanism was the result of a chance accumulation of parts that had somehow fallen together. Rather, the precise mechanism surely implies a designer who planned the constructions of the overall object. In 'Intelligent Design' similar arguments are made at the biochemical level, about the complex systems of proteins which only function after they have independently come into existence and become coordinated into a 'machine' such as a flagellum.  

The challenge of conceptual change

The parallel concerns the nature of conceptual changes between different conceptual frameworks. Paul Thagard (e.g., 1992) has looked at historical cases and argued that such shifts depend upon judgements of 'explanatory coherence'. For example, the phlogiston theory explained a good many phenomena in chemistry, but also had well-recognised problems.

The very different conceptual framework developed by Lavoisier [the Lavoisiers? **] (before he was introduced to Madame Guillotine) saw combustion as a chemical reaction with oxygen (rather than a release of phlogiston), and with the merits of hindsight clearly makes sense of chemistry much more systematically and thoroughly. It seems hard now to understand why all other contemporary chemists did not readily switch their conceptual frameworks immediately. Thagard's argument was that those who were very familiar with phlogiston theory and had spent many years working with it genuinely found it had more explanatory coherence than the new unfamiliar oxygen theory that they had had less opportunity to work with across a wide range of examples. So chemists who history suggests were reactionary in rejecting the progressive new theory were actually acting perfectly rationally in terms of their own understanding at the time. ***

Evolution is counter-intuitive

Evolution is not an obvious idea. Our experience of the world is of very distinct types of creatures that seldom offer intermediate uncertain individuals. (That may not be true for expert naturalists, but is the common experience.) Types give rise to more of their own: young children know that pups come from dogs and grow to be adult dogs that will have pups, and not kittens, of their own. The fossil record may offer clues, but the extant biological world that children grow up in only offers a single static frame from the on-going movie of evolving life-forms. [That is, everyday 'lifeworld' knowledge can act as substantial learning impediment – we think we already know how things are.]

Natural selection is an exceptionally powerful and insightful theory – but it is not easy to grasp. Those who have become so familiar with it may forget that – but even Darwin took many years to be convinced about his theory.

Understanding natural selection means coordinating a range of different ideas about inheritance, and fitness, and random mutations, and environmental change, and geographical separation of populations, and so forth. Put it all together and the conceptual system seems elegant – perhaps even simple, and perhaps with the advantage of hindsight even obvious. It is said that when Huxley read the Origin of Species his response was "How extremely stupid not to have thought of that!" That perhaps owes as much to the pedagogic and rhetorical qualities of Darwin's writing in his "one long argument". However, Huxley had not thought of it. Alfred Russel Wallace had independently arrived at much the same scheme and it may be no coincidence that Darwin and Wallace had both spent years immersing themselves in the natural history of several continents.   

Evolution is counter-intuitive, and only makes sense once we can construct a coherent theoretical structure that coordinates a range of different components. Natural selection is something like a shed that will act as a perfectly stable building once we have put it together, but which  it is very difficult to hold in place whilst still under construction. Good scaffolding may be needed. 

Incremental change

The response to those arguments about design in evolution is that the many generations between the land animal and the bird, or the blind animal and the mammal, get benefits from the individual mutations that will collectively, ultimately lead to the wing or mammalian eye. So a simple eye is better than no eye, and even a simple light sensitive spot may give its owner some advantage. Wings that are good enough to glide are useful even if their owners cannot actually fly. Nature is not too proud to make use of available materials that may have previously had different functions (whether at the level of proteins or anatomical structures). So perhaps features started out as useful insulation, before they were made use of for a new function. From the human scale it is hard not to see purpose – but the movie of life has an enormous number of frames and, like some art house movies, the observer might have to watch for some time to see any substantive changes. 

A pedagogical suggestion – incremental teaching?

So there is the irony. Scientists counter the arguments about design by showing how parts of (what will later be recognised as) an adaptation actually function as smaller or different advantageous adaptations in their own right. Learning about natural selection presents a situation where the theory is only likely to offer greater explanatory coherence than a student's intuitive ideas about the absolute nature of species after the edifice has been fully constructed and regularly applied to a range of examples.

Perhaps we might take the parallel further. It might be worth exploring if we can scaffold learning about natural selection by finding ways to show students that each component of the theory offers some individual conceptual advantages in thinking about aspects of the natural world. That might be an idea worth exploring. 

(Note. 'Representing evolution in science education: The challenge of teaching about natural selection' is published in B. Akpan (Ed.), Science Education: A Global Perspective. The International Edition is due to be published by Springer at the end of June 2016.)

Notes:

* First published 30th April 2016 at http://people.ds.cam.ac.uk/kst24/

** "as Madame Lavoisier, Marie-Anne Pierrette Paulze, was his coworker as well as his wife, and it is not clear how much credit she deserves for 'his' ideas" (Taber, 2019: 90). Due to the times in which they works it was for a long time generally assumed that Mme Lavoisier 'assisted' Antoine Lavoisier in his work, but that he was 'the' scientist. The extent of her role and contribution was very likely under-estimated and there has been some of a re-evaluation. It is known that Paulze contributed original diagrams of scientific apparatus, translated original scientific works, and after Antoine was executed by the French State she did much to ensure his work would be disseminated. It will likely never be know how much she contributed to the conceptualisation of Lavoisier's theories.

*** It has also been argued (in the work of Hasok Chang, for example) both that when the chemical revolution is considered, little weight is usually given to the less successful aspects of Lavoisier's theory, and that phlogiston theory had much greater merits and coherence than is usually now suggested.

Sources cited:
  • Taber, K. S. (2017). Representing evolution in science education: The challenge of teaching about natural selection. In B. Akpan (Ed.), Science Education: A Global Perspective (pp. 71-96). Switzerland: Springer International Publishing
  • Taber, K. S. (2019). The Nature of the Chemical Concept: Constructing chemical knowledge in teaching and learning. Cambridge: Royal Society of Chemistry.
  • Thagard, P. (1992). Conceptual Revolutions. Oxford: Princeton University Press.

Many generations later it's just naturally always having fur

Keith S. Taber

Image by MirelaSchenk from Pixabay 

Bert was a participant in the Understanding Science Project. In Y11 he reported that he had been studying about the environment in biology, and done some work on adaptation. he gave a number of examples of how animals were adapted to their environment. One of these examples was the polar bear.

…our homework we did about adapting, like how polar bears adapt to their environments, and camels….

And so a polar bear has adapted to the environment?

Yeah.

So how has a polar bear adapted to the environment?

Erm, things like it has white fur for camouflage so the prey don't see it coming up. Large feet to spread out its weight when it's going over like ice. Yeah, thick fur to keep the body heat insulated.

Bert gave a number of other examples, including dogs that were bred with particular characteristics, although he explained this in terms of inheritance of acquired characteristics: suggesting that dogs that have been taught over and over to retrieve have puppies that automatically have already got that sense. Bert realised that his example was due to the work of human breeders, and took the polar bear as an example of a creature that had adapted to its environment.

Yeah, so how does adaption take place then? …

I don't know. It may have something to do with negative feedback.…Like you have like, you always get like, you always get feedback, like in the body to release less insulin and stuff like that. So in time … organisms, learn to adapt to that. Because if it happens a lot that makes a feedback then it comes, yeah then they just learn to do that.

Okay. Give me an example of that. I'm trying to link it up in my head.

Okay, like the polar bear, like I don't know. It may have started off just like every other bear, but because it was put in that environment, like all the time the body was telling it to grow more fur and things like that, because it was so cold. So after a while it just adapted to, you know, always having fur instead of, you know, like dogs shed hair in the summer and stuff. But like if it was always then they'd just learn to keep shedding that hair.

So if it was an ordinary bear, not a polar bear, and you stuck it in the Arctic, it would get cold?

Yeah.

But you say the body tells it to grow more fur?

Erm, yeah.

How does that work?

I'm not sure, it just … I don't know. Like, erm, like the body senses that it's cold, it goes to the brain, and the brain thinks, well how is it going to go against that, you know, make the body warmer. And so it kind of, you know, it gives these things.

So Bert seemed to have notion of (it not the term) homoeostasis, that allowed control of such things as levels of insulin. He recognised thus was based on negative feedback – when some problematic condition was recognised (e.g. being too cold) this would trigger a response (e.g., more insulation) to bring about a countering change.

However, in Bert's model, the mechanism was not initially automatic. Bert thought that this process which initially was based on deliberation became automatic over many generations…

I see. So the bear has already got a mechanism which would enable it to have more fur, but it's turned on to some extent by being put into the cold?

Yeah.

And then over a period of time, what happens then?

Erm I guess it just it doesn't really need that impulse of being cold, it's just naturally there now, to tell it to do it more.

So how does that happen? Is this the same bear or is this many generations later?

I would probably think many generations later.

Right, so if it was just one particular bear, it wouldn't eventually just produce more hair automatically itself, but its offspring eventually might?

Yeah.

So how does that happen then?

I don't know. Probably from DNA or something. We haven't gone over that yet.

So for Bert, the individual bear could change its characteristics through activating a potential mechanism (in this case for keeping year-round thick fur) through a process of sensing and responding to environmental conditions. Over many generations this changed characteristic could become an automatic response by eventually being coded into the genetic material. As with his explanation of selective breeding, Bert invoked a model of evolution through the inheritance of acquired characteristics, rather than the operation of natural selection on the natural range of characteristics within a breeding population.

Like many students learning about evolution, Darwin's model of variation offering the basis for natural selection was not as intuitively appealing as a more Lamarckian idea that individuals managed to change their characteristics during their lives and pass on the changes to their offspring. This is an example of where student thinking reflects a historical scientific theory that has been discarded rather than the currently canonical scientific ideas taught in schools.

Is the theory of evolution e=mc²?

Keith S. Taber

Images from Pixabay

Adrian was a participant in the Understanding Science Project. When I spoke to him during the his first year (Y12) of his 'A level' course he told me he had been studying quantum theory, and I asked him about the name 'quantum theory'. He suggested that a theory is an idea that can be proven, but struggled to suggest any other scientific theories.

I suggested the theory of evolution:

What about the theory of evolution? Would you count that as a theory?

Yes, but I am not familiar with it. Was it e=mc²?

That's relativity.

Relativity.

I was thinking evolution?

I don't know that one.

Not sure about evolution at all?

No.

Of course there is more than one theory of evolution, but natural selection was a compulsory topic in the school curriculum, and widely referred to as 'the theory of evolution'. Adrian, however, seemed to have no recollection of hearing about evolution at all. It is inconceivable that he had not met the term in school or elsewhere, but it was not something he was bringing to mind in response to my questioning.

So who's not a clever little virus then?

The COVID-19 virus is not a clever or sneaky virus (but it is not dumb either) 1

Keith S. Taber

Image by Syaibatul Hamdi from Pixabay 

One of the things I have noticed in recent news reports about the current pandemic is the tendency to justify our susceptibility to the COVID-19 coronavirus by praising the virus. It is an intelligent and sneaky foe, and so we have to outwit it.

But no, it is not. It is a virus. It's a tiny collection of nucleic material packaged in a way that it can get into the cells which contain the chemical resources required for the virus to replicate. It is well suited to this, but there is nothing intelligent about the behaviour. (The virus does not enter the cell to reproduce any more than an ice cube melts to become water; or a hot cup of coffee radiates energy to cool down; or a toddler trips over to graze its knee rather than because gravity acts on it.) The virus is not clever nor sneaky. That would suggest it can adapt its behaviour, after reflecting upon feedback from its interactions with the environment. It cannot. Over generations viruses change – but with a lot of variations that fail to replicate (the thick ones in the family?)

Yet any quick internet search finds references to the claimed intellectual capacities of these deadly foes. Now of course an internet search can find references to virtually anything – but I am referring to sites we might expect to be authoritative, or at least well-informed. And this is not just a matter of a hasty response to the current public health emergency as it is not just COVID 19, but, it seems, viruses generally that are considered intellectually superior.

Those smart little viruses

The site Vaccines Today has a headline in a posting from 2014, that "Viruses are 'smart', so we must be smarter", basing its claims on a lecture by Colin Russell, Royal Society University Research Fellow at Cambridge University. It reports that "Dr Russell says understanding how 'clever' viruses are can help us to outsmart them". (At least there are 'scare quotes' in some of these examples.)

An article from 2002 in an on-line journal has the title "The contest between a clever virus and a facultatively clever host". Now I have moaned about the standard of many new internet journals, but this is the Journal of the Royal Society of Medicine, and the article is in volume 95, so I think it is safe to apply the descriptor 'well-established' to this journal.

A headline in Science news for Students (published by Society for Science & the Public) from 2016 reads "Sneaky! Virus sickens plants, but helps them multiply". I am sure it would not take long to find many other examples. An article in Science refers to a "nasty flu virus".

Sneaky viruses

COVID-19 is a sneaky virus according to a doctor writing in the Annals of Internal Medicine. Quite a few viruses seem to be sneaky – the the human papillomavirus is according to an article in the American Journal of Bioethics. The World Health Organisation considers that a virus that causes swine fever, H1N1, is sneaky according to an article in Systematic Reviews in Pharmacy, something also reported by the BMJ.

There are many references in the literature to clever viruses, such as Epstein‐Barr virus according to a piece in the American Journal of Transplantation. The Hepatitis C virus is clever according to an article in Clinical Therapeutics.

Science communication as making the unfamiliar, familiar

Science communication is a bit like teaching in that the purpose of communication is often to be informative (rather than say, social cohesion, like a lot of everyday conversation {and, by the way,it was another beautiful day here in Cambridgeshire today, blue sky – was it nice where you are?}) and indeed to make the unfamiliar, familiar. Sometimes we can make the unfamiliar familiar by showing people the unfamiliar and pointing it out. 'This is a conical flask'. Often, however, we cannot do that – it is hard to show someone hyperconjugation or hysteresis or a virus specimen. Then we resort to using what is familiar, and employing the usual teacher tricks of metaphor, analogy, simile, modelling, graphics, and so forth. What is familiar to us all is human behaviour, so personification is a common technique. What the virus is doing, we might suggest, is hijacking the cell's biochemical machinery, as if it is a carefully planned criminal operation.

Strong anthropomorphism and dead metaphors

This is fine as far as it goes – that is, if we use such techniques as initial pedagogic steps, as starting points to develop scientific understanding. But often the subsequent stage does not happen. Perhaps that is why there are so many dead metaphors in the language – words introduced as metaphors, which over time have simple come to be take on a new literal meaning. Science does its fair share of borrowing – as with charge (when filling a musket or canon). Dead metaphors are dead (that is metaphorical, of course, they were never actually alive) because we simply fail to notice them as metaphors any more.

There are probably just as many references to 'clever viruses' referring to computer viruses as to microbes – which is interesting as computer viruses were once only viruses metaphorically, but are now accepted as being another type of virus. They have become viruses by custom and practice, and social agreement.

Whoever decided to first refer to the covalent bond in terms of sharing presumably did not mean this in the usual social sense, but the term has stuck. The problem in education (and so, presumably, public communication of science) is that once people think they have an understanding, an explanation that works for them, they will no longer seek a more scientific explanation.

So if the teacher suggests an atom is looking for another electron (a weak form of anthropomorphism, clearly not meant to be taken too seriously – atoms are not entities able to look for anything) then there is a risk that students think they know what is going on, and so never seek any further explanation. Weak anthropomorphism becomes strong anthropomorphism: the atom (or virus) behaves like a person because it has needs and desires just like anyone else.

Image by Tumisu from Pixabay 

Why does it matter?

Perhaps in our current situation this is not that important – the public health emergency is a more urgent issue than the public understanding of the science. But it does matter in the long term. Viruses are not clever – they have evolved over billions of years, and a great many less successful iterations are no longer with us. The reason it matters is because evolution is often not well understood.

As an article in Evolution News and Science Today (a title that surely suggests a serious science periodical about evolution) tells us again that "Viruses are, to all appearances, very clever little machines" and asks "do they give evidence of intelligent design" (that is, rather than Darwinian natural selection, do they show evidence of having an intelligent designer?) After exploring some serious aspects of the science of viruses, the article concludes: "So it seems that viruses are intelligently designed" – that is, a position at odds with the scientific understanding that is virtually a consensus view based on current knowledge. Canonical science suggests that natural processes are able to explain evolution. But these viruses are so clever they must surely have been designed (Borg technology, perhaps?)

This is why I worry when I hear that viruses are these intelligent, deliberate agents that are our foes in some form of biological warfare. It is a dangerous way of thinking. So, I'm concerned when I read, for example, that the cytomegalovirus is not just a clever virus but a very clever virus. Indeed, according to an article in Cell Host & Microbe "CMV is a very clever virus that knows more about the host immune system and cell biology than we do". Hm.

(Read about 'anthropomorphism')

Footnote:

1. The subheading was amended on 4th October 2021, after it was quite rightly pointed out to me that the original version, "COVID-19 is not a clever or sneaky virus (but it is not dumb either)", incorrectly conflated the disease with the virus.

Puppies that automatically retrieve your stick

Dogs that have been taught over and over to retrieve have puppies that automatically have already got that sense 

Keith S. Taber

Bert was a participant in the Understanding Science Project. In Y11 he reported that he had been studying about the environment in biology, and done some work on adaptation. he gave a number of examples of how animals were adapted to their environment. When asked to explain how this occurred he initially used an example of selective breeding in dogs.

…our homework we did about adapting, like how polar bears adapt to their environments, and camels….

And so a polar bear has adapted to the environment?

Yeah.

So how has a polar bear adapted to the environment?

Erm things like it has white fur for camouflage so the prey don't see it coming up. Large feet to spread out its weight when it's going over like ice. Yeah, thick fur to keep the body heat insulated.

What about a camel then?

Well it has long eyelashes to keep the sand out of it. It has pretty much all its fat stored in its hump so that it can erm, so all the body, so that not much body heat is produced from everywhere else. It doesn't have hair on its belly to increase heat loss. And yeah, oh yeah, they're quite big so it has quite a lot of grip on the sand.

…

No, okay. So do you have any other examples of adaption?…

Oh well, well there's humans isn't there. Because like they started off like with an arched back and they went on all-fours and everything. And well their minds obviously have adapted and evolved, yeah. Erm (pause) and dogs, they have different … because people who are actually breeders, they, when they breed dogs they breed them to be like, like Retrievers. Because they've like been taught over and over to retrieve. And so when they have puppies then they automatically have already got that sense. That's not really adapting though is it?

So somebody has trained these dogs to go and, when they shoot birds or something, they're trained to go and get the birds they've shot and bring them back?

Yes.

Okay. And if you do that enough, baby puppies bred from those dogs will just know to do that?

Well they won't know to do that, but they'll already have that kind of sense. And like, well my dog that I have, it's a Chocolate Labrador, and I said look, she had webbed feet which is adapted for swimming, for retrieving, I don't know, retrieving birds from water or something.

Although Bert was aware of how traits could be passed on to offspring he was thinking in terms of the inheritance of acquired characteristics – a Lamarkian model of evolution – rather than the selection of qualities that vary across a population. For some pupils the notion of evolution makes sense, but in terms of changes that occur in an individual in response to environmental challenges being somehow passed on to their offspring. The inheritance of acquired characteristics is a scientific concept, that is a historical (scientific) concept, but not a canonical (current scientific) concept, so Bert's understanding of evolution would be considered an alternative conception.

(Bert then went on to consider an example of a naturally occurring adaptation, the polar bear's fur, however he again considered this in terms of an acquired characteristic being passed on to future generations.)

Atoms evolved so that they could hold on to each other

Bert Suggests Chemical Bonding Evolved 

Keith S. Taber

Bert was a participant in the Understanding Science Project. During one interview he reported that he had just completed a topic of alkanes and alkenes in his chemistry classes. He explained that a carbon atom has "to have four bonds", so if a carbon atom had "only got one two carbons on one side and one hydrogen then it'll make a double bond, to have four bonds". So I asked him what he understood a bond to be:

I: …what's a bond?

B: A bond is erm, it just, it's something to hold, hold two atoms together.

I: So what might you use to hold two atoms together?

B: Erm, So they can be kept, so that they're not too, I think it's just to make, so it can make big lines so it can erm, oh, so they, so not every, so because solids they have erm, I guess a lot of bonds, to keep it all, all together, I'm guessing. And erm like gas has a lot less bonds because it's a lot more free.

I: That makes sense [Bert], I'm just wondering what you would use to bond two atoms together. … I'm just wondering what kind of thing you use to bond two atoms together.

B: Erm • • I'm not sure. I guess, I guess they were just, when er, they're made with it I guess.

I: Yeah. Do you think it's made of adhesive? … is it made of a glue do you think?

B: No, I don't think so. I think it was like, I don't know, it could have been like evolution, like.

I: Ah.

B: Yeah, the atoms evolved so that they could hold on to each other.

I: Oh I love that. • • • The atoms evolved so that they could hold on to each other?

B: I guess so. That's how the world was made.

In this interview segment Bert seems not to have considered the nature of the bonds between atoms, but just to have accepted what he has learnt about valency. When asked about the nature of the bond he could offer no mechanism for bonding, but instead suggested that chemical bonds had evolved as "that's how the world was made". Here Bert is drawing upon a general explanation considered to be universal in the domain of living things, but applying his learning from biology to explain a physical phenomena.

This seems to be a creative association drawing upon prior learning, but the idea of evolution is being used outside is canonical range of application, leading to a potential associative learning impediment. Potentially, Bert's thinking about evolution as explaining how atoms can bond (a potential explanation about origins, though inappropriate if evolution is understood as natural selection) could stand in place of seeking a physical explanation for the nature of bonding.

A theory is an idea that can be proven

Keith S. Taber

Adrian was a participant in the Understanding Science project. When I spoke to him during the his first year (Y12) of his 'A level' course he told me he had been studying quantum theory, and I asked him about the name 'quantum theory'.

So why do we call it the quantum theory because that is an unusual name isn't it?

I don't know.

No?

No.

What's a theory?

An idea that can be proven? Yes.

A modern understanding of the nature of science does not considered that theories are the kinds of things that can be proved in any simply and straightforward sense. Widely accepted theories are usually supported by a good deal of evidence, and individual components of them may be subject to experimental testing, but a theory as a whole can not be proved as such.

I wanted to find out what scientific theories Adrian was familiar with:

Give me an example of a theory you are familiar with?

I'm familiar with?

Yes. Apart from the quantum theory what other theories do you know?

Pythagoras's theorem.

Okay.

It's completely different, which is basically is a squared equals b squared plus c squared…What other theories, erm… I'm not sure.

So Adrian's only other suggestion of a theory was actually a mathematical theorem (which could be logically deduced within a particular system of axioms, unlike a scientific theory which refers to some aspect of the natural world).

I suggested the theory of evolution that Adrian should have met during his secondary science course earlier in the school: but Adrian claimed he was "not familiar with it" asking if it was "e=mc²"(Is the theory of evolution e=mc²?). Adrian recognised this as a formula, but thought that counted as a theory,

Tell me about e=mc² then because I am teaching that this afternoon so… I am teaching that subject this afternoon, so tell me about that, I need to know about that.

It's a formula. I am not sure that it works out, I am not sure that I understand it, was it Isaac Newton I think sort of come up with the theory. I have never used it and I don't know what you would use it for. …

You think that might be a theory as well?

Yes.

and the theory is an idea that can be proven?

Yes.

Yes. So do you think the various theories that scientists have come up with over the years have been proven?

Yes, but some would have limitations to where they can be sort of – How they can be used if that makes sense.

So they have got a kind of range of applications?

Yes.