Evolution, ethics and the morality of vegetarianism 


Some weeks ago, I wrote an essay on the subject of evolutionary ethics in which I found myself arguing that if altruism towards one's own relatives and immediate kin is the root cause of moral behaviour (as appears to be the case) then, by extension, we have a moral responsibility not only towards other people, but towards animals too, and ultimately to all other forms of life. This might strike you as a fairly radical claim, but the logic is hard to resist, and as a result I have decided to substantially cut down on the amount of meat that I eat with a view to becoming completely vegetarian. 

The argument goes something like this:

1. Evolution functions through natural selection at the level of individual genes, or gene complexes, rather than at the individual or group level. (If you are in any doubt about this, I'd recommend reading Richard Dawkins’ excellent The Blind Watchmaker, or the seminal The Selfish Gene, both of which make the point pretty conclusively.)

2. Evolutionary pressures favour the emergence of altruism—i.e. behaviour that benefits others, even though it may be of little benefit or actually detrimental to those who exhibit it—because in the long term this maximises the survival chances of the relevant genes. In other words, if people do nice things, then even though it may ultimately be to their own cost, these generous acts will have helped others to survive and so are beneficial to the species as a whole, and therefore selected for by evolution. In this way, a state of equilibrium between altruistic and selfish genes and/or behaviour in the population at large is reached.

3. Altruism is the source of—and the justification for—morality. This premise may be a little harder to prove, but intuitively at least it would seem that all moral acts involve someone doing something that may not be in their own (short-term) best interests, despite it being the 'right' thing to do. In other words, there is a trade-off between doing what is best for oneself and doing what is best for others or the community as a whole, and such altruism is at the root of what we would call moral behaviour.

4. (And this is the crucial point.) If altruism towards genetically related individuals is the source of human morality then, given our understanding of evolution and genetic science, we are related to all other animals and living things, we have a moral responsibility towards other animals and living things in proportion to how closely we are related to them.

Now, this last point is doing most of the work, so let me break it down a little. It is well known that human being share over 99% of our DNA—that is, the genetic material that provides the instructions for how to make a human being—with chimpanzees, our closest surviving relative. Many of our genes are more or less identical to those found in other mammals, such as cows, and even plants and bacteria share a very large proportion of the same genetic material as a result of having evolved from a common ancestor over a period of billions of years. Evolutionary biology, then, tells us that we have more in common with other living creatures than what differentiates us from them, at least from a genetic point of view.

Secondly, most of us would accept that we have a greater responsibility towards our children and other members of our family than we do towards complete strangers. If a number of people were stranded on a desert island and we had the chance to rescue only a few of them, we would typically choose our own children first, followed by other members of our family, friends*, and only then would we rescue other people that were unrelated or otherwise unknown to us. (We might also choose other children on the basis that they have a longer life ahead of them and are more likely to contribute to the survival of the species. However, the key point is that we make such choices based on the basis of the survival of our genes, even if those genes happen to be located in other people.) This selective aspect of morality is something that is not well catered for by traditional ethical theories, which tend to say that we have the same moral responsibilities towards everybody else, except where special duties or agreements apply, but is easily explained in evolutionary terms as the result of an inbuilt (i.e. previously selected for) disposition towards helping those with whom we are likely to share the largest amount of genetic material. By helping them, we are in a sense helping our own genes to survive, which are merely clones of the same genetic patterns found in other people, such as close family members.

Now, putting these two points together, if we are obligated towards our relatives and others because we share genetic material with them, and we also share a large amount of genetic material with chimpanzees and other animals, then this implies that we also have a moral responsibility towards them, and by extension, towards all other living things. If you accept this argument, then the question is not one of whether we have such moral responsibilities towards animals, but to what extent those responsibilities apply, and how best we can meet them. Because we are more closely related to other mammals, such as monkeys, pigs, cows, etc., it follows that we have a greater responsibility towards them than to other species, such as birds, fish or insects, and still less towards plants and other flora. Nevertheless, we have a distinct and definite moral responsibility towards each and every living species on this planet, which is a very long way way from saying that plants and animals exist entirely for our benefit, and that we should feel free to use and exploit them as we see fit.

Of course, a sceptic might argue that if we have a moral responsibility towards chickens, for example, then we have similar responsibilities towards carrots and other vegetables, and so being a vegetarian is just as unethical as eating meat! However, a more sensible reading would be that we have a greater responsibility towards animals because we have more in common with them, and that, whilst it is true that we have a responsibility towards carrots, we have been blessed with sufficient mental faculties and free will to be able to reach a balance between looking after our own survival and discharging our moral responsibilities to others as best we can. So again, the question is whether it is justifiable to exploit animals for food, given that we know them to be closely related to ourselves and have a similar entitlement to ethical treatment on entirely rational grounds.

My own feeling is that this argument is sound, and that ethics itself should be seen as an evolving and ever changing science (if science is the right word). It stands to reason that a more sophisticated understanding of our evolutionary heritage and place in the world will shed more light on the meaning of right and wrong, and as a result, our practices and customs will inevitably change. The only question is whether you can in good conscience hold such beliefs whilst simultaneously continuing to eat animals, when we know this to be both unnecessary for survival and actually detrimental to the human race as a whole due to the inefficient use of land that could be used to grow crops, etc.—as well as being obviously fatal for the poor creatures involved. At the very least it makes a good case that animal (and plant!) welfare is not just a nicety but a moral duty. However, I am forced to conclude that it is actually unethical to eat meat, and continuing to do so would be immoral, and so have recently committed myself to becoming a full-time vegetarian.

How I am going to achieve this aim in practice is another matter entirely, as I enjoy a good steak, roast chicken or ham sandwich as much as anyone. However, I have so far managed to cut red meat out of my diet entirely, and in accordance with the above order of precedence, have more or less stopped eating any meat that comes from other mammals (primarily pork). The next step will be the most challenging as it means cutting out chicken, which I love, although I am not sure whether I will go as far as to stop eating fish, provided that it comes from sustainably managed organic stock. Similarly, dairy products such as milk, cheese, etc. are OK, provided that they come from organic farms and that the animals have been well treated and allowed to live to the end of their natural lives.

So far, cutting out meat has actually been easier than I imagined, as once I started, I found that I actually wanted to eat less meat. A lot of the other things I've found to replace it (various kinds of vegetables, nuts, and in some cases fish) are actually quite tasty, and although I need to brush up on my vegetarian cookery skills, I can actually imagine myself eating no meat whatsoever for the first time ever. Regardless of whether you agree with the above argument or not, it's certainly worth giving some thought as to whether it is right that supposedly intelligent creatures such as ourselves should kill other animals for food, and if so, under what conditions. We have a responsibility to look after other the creatures with whom we share this world, and that may just be something we need to remind ourselves of once in a while.

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* Friendship is an interesting case. Given that it's incredibly difficult, and often impossible, to tell whether we are genetically related to another individual, it may be that we treat friends as honorary family members on the grounds that they probably have quite similar genes, which is why we like them in the first place. This makes sense when you think that friends are generally people with whom you instinctively feel that you have something in common with, and as a result, may well share a larger proportion of your genetic and/or cultural traits than other people. (I have omitted the role of cultural or ‘memetic’ transmission in the above discussion for simplicity, but the basic principle is the same.) 

Posted on Friday - June 03, 2005 at 06:27 PM            

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