To borrow a concept from evolutionary biology itself, I’m beginning to encounter that old, familiar conference cost-benefit trade off. Is the benefit of staying up drinking and talking about interesting biology with articulate, thinking people worth the cost of falling asleep the next day during interesting seminars by other articulate, thinking people? The trouble is, every time I’m called upon to make that decision I’m already thinking and talking about biology and the next day’s formal sessions seem a long way off. Again, taking my inspiration from evolution, I usually end up making the decision that seems to offer the best reward at the time, without considering the long-term consequences.
Now, on the morning of Day Three, there are consequences to suffer but, as usual, the effort in concentrating is worth it. The first lecture of each morning at the European Society for Evolutionary Biology is an overview of a particular field and so far they have all been at least clarifying, often fascinating and sometimes provocative. Today’s, by Ian Tattersall of the American Museum of Natural History, was no exception and gave an overview of human origins in the context of one of the remaining big questions of evolution; how humans developed a symbolic, internal representation of the world.
While Ian was the first to admit that he didn’t have anything like an answer to this, his perspective as a palaeoanthropologist does at least mean he can examine the biological context in which such a thing might evolve. His analysis suggests that the development of human symbolic and linguistic culture didn’t evolve gradually, generation by generation but rapidly, as an emergent property once all the component parts (each of them advantageous on their own, of course) were already present, echoing some of the ideas from complexity theory that are staring to be used to help understand the origin of other complex biology. While sure to be controversial, this idea is at least an attempt to start formally addressing one of the difficult problems with which evolutionary theory needs to get to grips. And that’s not going to happen without enlightened science funding.
That’s one of the most exciting things about a conference like this: you get to hear what some of the brightest and hard working minds are thinking right at the moment; you get to see their work in progress. That was underlined by yesterday’s morning lecture by Massimo Pigliucci from Stony Brook University, New York. He discussed whether there is a new evolutionary synthesis just over the horizon.
This idea of a scientific synthesis is pretty key to how we understand evolution. When Darwin and Wallace put forward their theory of evolution by natural selection (arguably itself a synthesis of ideas that were current at the time) our understanding of the natural world was fundamentally changed, probably for good. But there was something missing. Darwin and Wallace didn’t have a coherent theory of heredity, how evolving traits are passed down from one generation to another, and that was a major missing piece.
It is one of the most famous ironies in science that Mendel published his work on inheritance very soon after the publication of The Origin of Species, as anyone who has seen any of the BBC’s coverage of Darwin Year must know by now, his work was largely ignored until it was rediscovered at the turn of the 20th Century. The putting together of Darwinism with Mendel’s findings about inheritance is an example of a synthesis, and what an example it is. The coherent theory it produced has become an enormously powerful explanatory force in biology and is essentially what is generally understood as “The Theory of Evolution”.
But scientists question, scientists explore. Seventy years of questioning and exploring this so-called Modern Synthesis of evolution has developed it and strengthened it but at the same time has brought its limits into sharper and sharper focus. Its principal limiting factor is that it is a theory of genes. Not only that, it is largely based on an idea of genes that pre-dates the enormous advances that have occurred in genetics in the last couple of decades. Is it time to look at what we have and see if it needs a good shake?
Massimo Pigliucci clearly thinks so. A short time ago he brought together sixteen of the leading evolutionary theorists in one place and let them do what biologists most love to do; talk about biology. The result of this was not a new synthesis (that would have been remarkable!) but a mapping out of the ideas at and just beyond the limits of the Modern Synthesis that have been gradually emerging since the middle of the last century. To quote directly from Massimo’s lecture, the questions we now need to look at are these:
- How do we factor development into evolutionary biology?
- Is evolution always gradual?
- Is selection the only organising principle?
- What are the targets of selection?
- Is there a discontinuity between micro- and macro-evolution?
- Is the question of inheritance settled?
- Where do evolutionary novelties come from?
- And what role does ecology play in evolution?
(Interestingly enough, these are just some of the questions that have come up through discussions on the Darwin Forum). It is too early to say if there is a new synthesis on the way and in a very large sense it doesn’t matter if there is or not. What is more important is that these questions are being asked honestly and productively. It certainly is a very interesting time to be an evolutionary biologist.