Jim was a good friend of mine; he was quite an unusual looking lad. I knew that he always wanted to settle down with a girl, but he wasn't a good conversationalist, and that compounded the problem he had with his looks. It just never happened for him. He died of a drink-related illness in his late thirties.
Patrick was good looking, friendly but always intensely shy. He was dominated by his parents and found it hard to cope. He ended up with mental problems and he was finally found floating in a local dock. He never married or had children.
A girl in my class died as a result of anaphylactic shock after being stung by a bee.
Ron was in my class too. He died at twelve, with his sister, in a fire. (All names changed.)
Ok! Ok! I do have some friends left.
My point is that all of the above people failed to pass on their genes. With a different roll of the genetic dice each of them, with the exception of Ron, would probably have families today. (The fire that killed Ron was a pure accident and therefore a random event outside of genetic influence.) When tragedies like this happen we don't think of them as being examples of natural (or sexual) selection, but that is, almost certainly, exactly what they are. I would be prepared to bet that each of you would be able to think of examples, like this, from within your own experience.
Much of the earlier part of "The Red Queen", reinforces this point; the book shows just how potent, powerful and all-pervasive natural selection is. It is a highly dynamic system; selective pressure is everywhere. It is remorseless, indefatigable and ubiquitous. Even if one accepts that the Red Queen hypothesis does demonstrate that this does not mean that adaptive change is happening all the time. Natural selection must always be active.
It should be obvious that given the awesome complexity of the "gene wars" that Ridley eloquently illuminates in the book, we humans could not possibly have escaped this all-pervasive pressure, because we too are part of nature.
Why, then, does the implicit assumption that evolution is not happening in modern populations seem to prevail? Ok Ridley is not the chief proponent of this view, Steven Rose and Steve Jones would be better targets for my attack; but here goes:
Down to specifics. One reason that the "Fully-Evolved-Human" fallacy has arisen is that it is clear that much natural selection in humans is genuinely not active. Lets ignore sexual selection, for the moment for the sake of simplicity. We can see that it is obvious that it simply doesn't matter whether we are big or small, fat or thin, whether we can run fast, whether we are clever enough to outwit predators, whether we are good leaders. Even if we are severely disabled and unable to contribute anything to society we might still survive long enough to reach breeding age. All this is unarguable and I don't (argue). There is probably also no argument that natural selection is not active in the role of disease resistance. The running battle against pathogens is probably continuing at the about the same rate as it always was, subject to the obvious consideration that we (at least in the West) are probably better nourished, and better able to fight disease than we might have been in our ancestral past. But this effect won't be regarded as sexy by most people - because due to the Red Queen effect it won't mean that humans are changing in any way we would generally think interesting.
But are other forms of natural selection active in modern human populations, acting, perhaps, on their BEHAVIOUR as opposed to their morphology? And - this is the BIG one - could there be adaptive evolution going on now?
Can it be that Ridley, Pinker and some (and maybe all) of the other modern science writers have been subsumed into a cultural milieu, where really important issues like this are ignored, or dodged.
When I asked Steven Pinker, in the web chat, about whether he thought that natural selection against what I call the "Need for Speed Effect" was happening in modern Western populations his answer was interesting, but perhaps not in the way he might have expected. He said:
Selection against speed -- once again, the key quesiton is how widespread and for how long that selection pressure lasts. A phenomenon of the last 50 years in a few industiralized countries will not affect the species, especially if the total number killed is relatively small -- e.g., 40,000 deaths a year in the US, which has something like 300 million people.
Why did Steve Pinker think that I was asking about the changes we might experience within our own lifetime? Shifts in gene frequency as a result of natural selection will surely be measured over genealogical time, and as a proportion of live births. The correct average percentage change would be: that subset of the number killed in car accidents who died because of their own
predisposition for the enjoyment of speed, over a period of time, against the number born in that same time period. i.e. the number killed
in an average year against the total number born
in an average year. I don't believe that Steve Pinker would not have understood the distinction. He thought I was asking a different question. He seemed to think that I wanted to know what effect it would have on a population in real time
. Maybe he would have thought it odd that I would ask about gene frequency changes over genealogical time. Gene frequency changes could never affect us on a day-to-day basis, and - as he pointed out - it would be impossible to predict how evolutionary change might affect us in the future. Both these points, incidentally, I entirely accept
I suspect that Steven Pinker's philosophical project is to improve and refine the social sciences in light of evolutionary psychology (or perhaps more accurately to dissolve the social sciences into evolutionary psychology as he thinks - probably rightly - that it has better scientific credentials). His aim being that social science might be more effective at dealing with human problems. I admire what he is trying to do; I think that his project is laudable and important, but the changes, he is interested in, happen in real time
. So perhaps he can be forgiven for misunderstanding, or maybe it was my fault for not framing my question properly.
My philosophical project is quite different. I want human beings to understand their true place in nature. Why do I bother concern myself with evolutionary change if it cannot possibly have any significant effect on our day-to-day lives, and if it is not possible to predict trends or read the future?
Our view of what it means to be human is important. If we could be evolving, as I suggest we might be, in whatever direction, it means that we are not well adapted to the world we are living in, and this could profoundly change the way we see ourselves. If adaptive change is happening, it underlines the point that passively accepting innate behaviour - which might be inappropriate in our modern world - and just doing what our innate behaviour tells us to do, because it feels right, could be an appalling and dangerous mistake.
So in what way is the cultural milieu affecting their judgement? Where have they gone wrong?
They are wrong because although we may not be able to predict how change might happen in the future, and it might be - because of the "wilderness of mirrors" problem I identified in my earlier posts - difficult to say how it is currently progressing. It is emphatically not true to imply that selection is not happening. Nor, even, is it safe to say that it is not happening in a co-ordinated and steady direction.
Now to the really interesting part:
The point they have lost in the cultural milieu is this: We did not evolve to fit the world in which we live now; each of us evolved the appropriate behaviour for a member of some ancient tribe on the Pleistocene savannah. Now because we no longer live in that environment it is not likely that any active selective process will be maintaining our behaviour in any way that would have been appropriate in the Pleistocene. To put it another way, any selective effects in modern populations are likely to be leading to ADAPTIVE CHANGE rather than maintaining stasis.
You may have noticed that nothing I have said rules out the possibility of hypothesising about changes that might have been effected during historical time. I won't go into more detail about this - this post is getting long enough. But we are not the supreme, super-intelligent species we seem to think we are. We almost certainly have behavioural attributes that are inappropriate to us in the modern world, and we should not think that evolution will not be adjusting gene frequencies in a consistent direction if any of the inappropriate behaviours are leading any of us to fail to pass on our genes. It should not be too difficult to work out what the inappropriate behaviours are, nor should it be impossible to identify possible trends in the historical record.
Are there good reasons why neither Ridley nor Pinker nor the others want to address these questions? There could be! They might well have thought this through and decided to leave it alone. It may not be cultural influence that is influencing their decision. After all much of this calls for subjective judgement because we don't yet know which genes are implicated in which particular behavioural attribute so we have no quantifiable data about how gene frequencies may vary from population to population due to selective effects during historical or pre-historical time. Then there is the problem that if we start arguing that the behaviour of different population groups might differ, it could be construed as providing ammunition for racist or extreme nationalist views. (This is an extremely good point, but it can be completely undermined if there is a case for putting tribalism on our list of proscribed archaic behaviour.) Or perhaps they think that at this stage all we can do is hypothesise and this might be outside of the remit of good scientists.
Perhaps someone should write a book.