Sunday, September 20, 2009
Why are My Eyes on the Front of My Head?
One of the problems with understanding evolution, and genetics in general, is that it is offer explained in the language of teleology. This appears to be an unconscious habit, but it confuses the learner and does not reflect the current state of knowledge.
A few days ago I spoke about a man who talks nonsense about human evolution, and who should have known better, since he is a man formed in the sciences, not some cultural studies/lit crit type.
Máximo Sandín has clearly decided to join the ranks of unreason because he thinks it will help him defend his beliefs with regard to great apes and animal conservation in general. Perhaps he also wants to get back at the international academy for not recognising him as a genius. And, as I said in the original post, he's just not as bright as he thinks he is.
He has no excuse. Plenty of people do have an excuse, however, because of the habit of saying that Homo erectus had a pronounced zygomatic arc because it had to chew hard foods, that a thick skull is to protect from blows, that a rabbit has big ears so that it can hear predators and zebras developed stripes to confuse lions. None of this is true, because no organ or characteristic or phenotype has a purpose beyond the use that an animal puts it to. They arrive by chance, by recombination or mutation, and they can be passed on down the generations. If they offer a significant survival advantage it is possible that, over a very long period of time, those with the new characteristic will outnumber those without, because they use it to live longer and reproduce more.
These changes come about by chance. They were not planned, conceived, created in response to some purpose. These characteristics do not develop because they are needed, but because those who have them happened to survive, while the rest got eaten. A group of Miocene equids did not sit around a table and say, 'Hey, let's paint ourselves black and white. That'll get the lions going.' It just happened, and they find it useful.
I'm not saying anything new or revolutionary here, just pointing out one source of misunderstanding. After all, if there is a purpose, there must be someone or something that can both conceive the purpose and bring about the means of achieving it.