Doktor S wrote:Evolution does not imply everything is constantly changing. Evolution implies change based on necessity. Crocodiles too, are essential unchanged from the crocs of a million years ago. Why? Because the crocodile thrives in it's envrironment, as is.
Actually, I'm not quite clear on why certain organisms last so long. Crocodiles, Horseshoe Crabs, Sharks, etc.
Evolution is passive, populations don't change because they want to, or need to. Change is usually small but constanst within the gene pool of a population. It's only when environmental factors cause a disparity in reproductive success that changes begin to accumulate. And more importantly, certain forms become extinct.
All of these long lived creatures must be associated with a particular environmental condition which is very stable. They are markers for classic environments.
Either that, or there must be very little diversity of genes within their population IN COMBINATION WITH stable environment.
In other words, selection is either occuring which maintains the classic gene pool for these creatures, OR they have no variability and have been VERY lucky to have been living in a stable environmental niche.
I wonder which it is. Or if it's both.
