The Sea Urchin Resurfaces
by BradfordThe sea urchin has been mentioned before at Telic Thoughts and elsewhere. More recently an article was linked to in which this was said:
Look, when Sherman stresses that the sea urchin has, in-expressed, the genes for the eyes and for antibodies (genes that are well known and fully active in later species), how can we not agree with him that canonical neo-Darwinism cannot begin to explain such facts?
Although this paper is not new there is also:
Embryonic development in the sea urchin requires trophic actions of the same neurotransmitters that participate in mammalian brain assembly
The rabbit seems to have the terrestrial mascot position sewed up but maybe the sea urchin can find a niche at Telic Thoughts.
June 7th, 2008 at 12:16 pm
I strongly recommend reading the entire article on Piattelli-Palmarini by Susan Mazur. It has a direct bearing on the discussion in aiguy's thread, and on the questions I posed there.
Specifically, Piattelli-Palmarini suggests a "new" role for selection in evolution: that is, not a "creative" role (as advocated by some neo-darwinists), but rather a "pruning" role. This is very similar to the point I made in the "RM & NS strawman" thread at my blog:
http://evolutionlist.blogspot....
The real engine of evolutionary change is not natural selection, but rather what Darwin called the "laws of variation", about which he admitted we were "ignorant". What has happened recently in evo-devo and related fields is that we have begun to figure out what the laws of variation are. As we have done so, we have discovered two things:
1) they are indeed laws with the same qualities as other natural laws
2) without natural selection they produce too much variation.
That is, there are newly discovered laws of development that strongly suggest that the large-scale evolution of life on Earth has not been "random", but rather (as Darwin himself suggested) the result of "laws acting around us". Furthermore, these laws "channel" the kinds of structural and functional characteristics that living organisms can have. Natural selection further "prunes" the immense amount of diversity produced by the operation of these laws, resulting in the actual living organisms and processes we observe around us.
If one wishes, one can of course say that "the unmoved Mover" established those laws and set the whole universe in motion.
Or, like Wittgenstein, one can say that there are some questions about the answers to which one must remain silent.
Comment by Allen_MacNeill — June 7, 2008 @ 12:16 pm