Looking at genes through a human lens

Why it's okay for biologists to anthropomorphize

DNA helix

We are told to be wary of looking at the natural world through a human lens. From projecting human intentions onto animals or using language that suggests natural processes have purpose, scientists are taught to avoid “anthropomorphising”. Yet, this kind of thinking can have significant explanatory power – think of Richard Dawkins’ famous “selfish genes”. In this article, Arvid Ågren mounts a defence of the gene's eye view of evolution and argues that if we are rigorous with our anthropomorphic thinking, we can see nature in a new light.

 

One of the first things you are taught as a biology student is to not anthropomorphize. To assign human emotions and intentions to plants and animals is something kids do, not proper scientists. Yet, we biologists anthropomorphize all the time.

Many of my colleagues consider this habit a bit of an embarrassment. Take, for example, the plant scientist David Hanke who lamented that

21 06 07.The gene illusion SUGGESTED READING The gene illusion By DenisNoble “Biology is sick. Fundamentally unscientific modes of thought are increasingly accepted, and dominate the way the subject is explained to the next generation. The heart of the problem is that we persist in making (literally) sense of a world that we now know to be senseless by attributing subjective values to the objectives in it, values that have no basis in reality.”

To Hanke and several other biologists, anthropomorphising leads to sloppy thinking, and it makes biology appear like a childish, rather than an exact, science. Look at chemistry and physics, they say, there the grown-ups have no time for embarrassing notions like purpose or intentionality. Serious scientific explanations are mechanical.

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“Anthropomorphic thinking is most useful when thinking about entities totally different to us”

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Purpose in biology and beyond

This tension arises because biology straddles what the biologist-cum-philosopher Massimo Pigliucci called the ‘teleonomic divide’. Teleonomy, as opposed to teleology, is the appearance of purpose. Biologists do not literally believe purpose actually exists or that living organisms are made of any mystical substance absent in non-living things. They are good materialists – no ghost in the machine here.

But biology clearly is different from physics and chemistry. The short and obvious answer to why it is different is that biologists study life. Living organisms are, of course, just like any physical object. They are built with the same protons and electrons as non-living things and are subject to the same laws of nature. Still, organisms also possess something that makes a racoon different from a rock. Racoons and other animals seem to have a sort of goal-directedness that the rock does not.

Unlike physicists and chemists (but just like economists and historians), biologists occasionally express their explanations in terms of purpose, goals, and strategies. We justify this by pointing to the unique achievement of Charles Darwin. With the theory of evolution by natural selection, he showed how a strictly mechanistic process of inheritance and reproduction can result in the appearance of design in nature: whether the polar bear’s fur that makes it blend into its surroundings or the flowers of the orchid that mimic female bees to attract males to pollinate them. Explaining the fact that organisms often appear almost perfectly suited for their environment – what we call adaptations – is a crowning achievement of Darwin’s theory and why it provides an explanatory bridge between mechanism and purpose.

This process of evolution by natural selection is the reason why it is allowed in biology to talk about purpose, to think in terms of intentions, to anthropomorphize. By couching such talk in terms of entities trying to maximize their fitness, purpose explanations can be brought into the realm of scientific explanations.

Not all ways of anthropomorphising are created equal, however. For example, there is a long tradition of personifying the process of natural selection itself. Darwin, drawing on the parallels between the choices made by a breeder and the operation of natural selection, often used this anthropomorphic way of thinking. The problem with those parallels is the crucial difference between artificial and natural selection: the former has foresight, which the latter lacks. Evolution has no pre-determined goal.

Another form of anthropomorphizing is to think of biological entities as agents with goals. The typical agent is an individual organism, and it may seem like the best application of anthropomorphic thinking is to the organisms most like us, such as chimps and gorillas. In fact, the opposite is true: anthropomorphic thinking is most useful when thinking about entities totally different to us. To see why, let’s return to Hanke’s frustration.

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Use the gene’s-eye view to generate hypotheses in our anthropomorphic language, which you then formalize with the precise language of mathematics

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The gene’s-eye view of evolution

Hanke identifies that most of his undergraduate students received their first introduction to the theory of evolution from books by Richard Dawkins. That Dawkins gets to represent the problem is perhaps not surprising. Few writers on evolution have reached a larger audience, and his books have provided the entry point to biology for generations of students. He also advocates a distinct approach to thinking about evolution and natural selection: anthropomorphising genes.

This is the so-called gene’s-eye view of evolution. It combines population genetics with a form of agential thinking inherited from the study of animal behaviour. The gene’s-eye view talks about genes in the same way we would talk about animals, as strategists pursuing their own goals. That is why it has also been known as selfish gene thinking as the selfish goal of each and every gene is to make it to the next generation.

The best way to achieve this selfish goal is typically to cooperate, which is why most phenotypic traits involve the coordinated action of many genes, each with a small effect. As will become clear below, genes do not always work towards the same goal, and the gene’s-eye view offers a powerful way to think about such genetic conflicts of interest.

Anthropomorphising genes is better than anthropomorphising organisms because it reminds us that we are dealing with teleonomic systems (that have the appearance of purpose), and not teleological systems (that have actual purpose). Richard Dawkins put it as follows:

“If we allow ourselves the license of talking about genes as if they had conscious aims, always reassuring ourselves that we could translate our sloppy language back into respectable terms if we wanted to, we can ask the question, what is a single selfish gene trying to do?”

The best form of such respectable terms is the formality offered by mathematics. You use the gene’s-eye view to generate hypotheses in our “sloppy” anthropomorphic language, which you then formalize with the precise language of mathematics using population genetics or game theory or whatever your modelling tool of choice may be. In a forthcoming paper, my colleague, Manus Patten, and I call this approach ‘licensed anthropomorphism’, a term we borrowed from Dawkins’s former graduate student Alan Grafen.

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“Trying to get rid of intentional terms in biology is pointless”

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Licensed anthropomorphism

A licensed anthropomorphism gives you the best of both worlds. It is an approach that brings together the creative power of anthropomorphic approaches like the gene’s-eye view with the rigidity of mathematical modelling. Formal modelling of an argument does more than just put it on more sound footing: it often reveals hidden assumptions that verbal models obscure and lead us to novel, unexpected results.

A good example of the approach comes from a paper Patten recently published. In it, he asked the simple question of whether a gene on an X chromosome should benefit males or females. In order to investigate this problem, let us first put ourselves in the shoes of an X-linked gene. Let us make the simplifying assumption that there is an equal number of males and females in the population and that each female has two X chromosomes and each male has one X and one Y chromosome. As an X-linked gene we can therefore infer that we will spend 2/3 of our time in females and 1/3 of our time in males as the generations go by. From this, we might expect that the best strategy for us as an X-linked gene is to benefit females. After all, that is where we will be most of the time and so favouring females seem to be the best bet. Patten’s modelling showed that this gene’s-eye view hypothesis holds, but only under certain assumptions about how genes affect fitness and how they interact. In fact, Patten demonstrated that if you relax the assumptions of the model, you can get the opposite result, that genes on the X chromosome should evolve to benefit males.

In Patten’s example, the gene’s-eye view starts out with an intriguing and important problem: what is the best strategy for a gene on the X chromosome? He then explores that question using the tools of theoretical population genetics and finds that part of the anthropomorphic hypothesis is confirmed, but capturing it mathematically also reveals unexpected nuances. This is licenced anthropomorphising at its best – creativity and rigidity unified, leading us to uncover features about the population dynamics of genes that we would otherwise not expect.

With his theory of evolution by natural selection, Darwin naturalized teleology and showed how the appearance of purpose in the living world is the product of a purely mechanistic process. In a teleonomic science like biology, it can therefore be ok to anthropomorphize. But, in order to do it well, you need the license of mathematics. Trying to get rid of intentional terms in biology is pointless; the best way to deal with the worries of anthropomorphising is to formalize it.

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