Evo-Devo

First off, I have been remiss in blogging. I hope I can remedy that. However, I cannot promise that I will. There are other writing projects that I am engaged in. Whenever I write entries for this blog, I feel that I could better use my time by working on those projects, but I don't really want to abandon blogging. It's a quandry. Perhaps I'll do what my friend David Matthews has done, which is to publish portions of my novel in my blog. I haven't made my mind up about that yet.

The Science section of today's New York Times discusses the most recent advances in the study of evolution. One of the hot fields right now is apparently what is called evo-devo. That is the study of the interaction between evolution and biological development. It is becoming clear that, at least in some cases, they are intimately connected. Some evolutionary changes that were thought to be due to mutations turn out to be caused by changes in the expression of pre-existing genes. For example, it had been thought the development of the hand and wrist structures in land animals was due to a mutation in the genes that control the development of the front fins in fish. This turns out not to be the case. Change the timing and length of expression of the gene that controls the growth of fins and you end up with the hand and wrist of amphibians and higher orders of animals. Interesting stuff. Perhaps that's why certain developmental disorders lead to children born with "flippers" instead of limbs.

The extent to which evolutionary changes are caused by mutations as opposed to gene expression is still an open question. I suspect that it will turn out to be some mix of the two but, after reading about it this morning, I've been mulling this over quite a bit. In scientific circles, it is generally agreed that the appearance of human intelligence was a fortuitous accident. If conditions had been a little bit different, perhaps humans never would have evolved. Perhaps an intelligent species of reptile would have come to dominate the earth, or something like that. What if that's wrong? What if human intelligence is immanent in the structure of the universe? Here's what I mean. What if the development of RNA and DNA, under favorable conditions, were the only means by which genetic coding could arise? I'm not talking about Divine edict or anything like that. Perhaps it's just the way the physics and chemistry of it work out. Perhaps it's also the case that the only way in which intelligence could arise would be in the way that it has arisen here on earth. No Adam and Eve would be necessary. It could just be the way the biological chemistry works out. Think of the implications. If there's alien intelligence on a planet orbiting some far star, it would have to be human intelligence. The flora and fauna of the planet would be much like ours.

This is all pure speculation of course. I suspect that the theological types would love it. God snapped his fingers and there went the Big Bang. Everything else was mere consequence. Yeah, right.