Complexity Slows Evolution
by MikeGeneFrom here:
What they found was that the "more advanced" species had faster overall rates of evolution. So, on average, the genes from humans and chimpanzees changed faster than genes from monkeys, which changed faster than those from mice.
They explained the trend as a correlate of smaller population size in the more advanced species. Species with smaller population size can more easily escape the harsh scrutiny of natural selection.
When they compared the pace of evolution among genes expressed in the brain, however, the order was reversed. When calibrated against the genomic average, brain genes in humans evolved more slowly than in other primates, which were slower than mice.
"We would expect positive selection to work most effectively on tissue-specific genes, where there would be fewer conflicting requirements," says Wu. "For example, genes expressed only in male reproductive tissues have evolved very rapidly."
Brains, however, "are intriguing in this respect," Wu says. Genes that are expressed only in the brain evolved more slowly than those that are expressed in the brain as well as other tissues, and those genes evolved more slowly than genes expressed throughout the rest of the organism.
The authors attribute the slowdown to mounting complexity of interactions within the brain. "We know that proteins with more interacting partners evolve more slowly," Wu said. "Mutations that disrupt existing interactions aren't tolerated."
December 28th, 2006 at 12:22 am
"We know that proteins with more interacting partners evolve more slowly"
Does anyone know of a paper which demonstrates this? This looks to be a secondary source for this information.
Comment by johnnyb — December 28, 2006 @ 12:22 am
December 28th, 2006 at 11:19 am
There is plenty of data to support the last statement. Mutations that disrupt existing interactions often lead to disease. It is also apparent that predictions of protein interfaces are not advanced by conservation knowledge alone.
One other point should be mentioned. An increase in brain size requires a corresponding increase in cranial capacity. This involves bone, not brain tissue. A mismatch between cranial capacity and brain size also has medical terms attached to it indicative of the relevant disease. As the builder of any home would know an extension on an existing ediface would begin with the construction of a suitable frame. The interior walls, wiring and the rest would follow. An significant increase in brain size would require coordinated development of both "frame' and "interior elements;" a unique phenomenon.
Comment by Bradford — December 28, 2006 @ 11:19 am
December 29th, 2006 at 11:39 am
There is absolutely nothing in the Darwinian paradigm that ever had anything to do with organic evolution beyond the elaboration of intraspecific varieties and in some instances subspecies. None of these are incipient species as Goldschmidt had concluded 66 years ago. They are all evolutionary dead ends doomed with very few exceptions to extinction.
Phylogeny, exactly like ontogeny has resulted entirely from within those organisms which were capable of leaving progeny fundamentally different from themselves. There is no evidence that such creatures any longer exist. Phylogeny has apparently finished with Homo sapiens the terminal mammalian product. Even true speciation no longer occurs. Just as ontogeny terminates with the death of the individual so phylogeny terminates with extinction of the species. I concur with Robert Broom and Julian Huxley that a new Genus has not appeared in two million years. I have extended this to claim that a new true species has not appeared in historical times. Only ontogeny remains. As for ontogeny and phylogeny -
"Neither in the one nor in the other is there room for chance."
Leo Berg, Nomogenesis, page 134
So much for Darwinism.
I have summarized this new evolutionary hypothesis in my paper - A Prescribed Evolutionary Hypothesis, Rivista di Biologia/Biology Forum 98: 155-166, 2005
"A past evolution is undeniable, a present evolution undemonstrable."
John A. Davison
Comment by John A. Davison — December 29, 2006 @ 11:39 am
December 29th, 2006 at 6:03 pm
Well come on folks. Surely my comment will evoke some kind of response won't it?
"A past evolution is undeniable, a present evolution undemonstrable."
John A. Davison
Comment by John A. Davison — December 29, 2006 @ 6:03 pm
December 29th, 2006 at 8:29 pm
Hi John. Is this yours?
http://www.uvm.edu/~jdavison/d...
Comment by Bradford — December 29, 2006 @ 8:29 pm
December 30th, 2006 at 4:34 am
Bradford
Yes . It was published in Rivista di Biologia/Biology Forum 91: 199-220, 1998
"A past evolution is undeniable, a present evolution undemonstrable."
John A. Davison
Comment by John A. Davison — December 30, 2006 @ 4:34 am
December 30th, 2006 at 1:03 pm
Yes . It was published in Rivista di Biologia/Biology Forum 91: 199-220, 1998
I'm reading your papers which I was unfamiliar with. I'm surprised you do not link to them with your name.
Comment by Bradford — December 30, 2006 @ 1:03 pm
December 30th, 2006 at 4:31 pm
Bradford
My name and my papers are well known both by the Bible Banging Fundies and the Darwimpian worshippers of the Great God Chance. I wouldn't give a nickel for either faction. I've been banned from most of their shabby "groupthink" forums, a sure sign of their insecurity. I wouldn't have it any other way.
Who is next?
I love it so!
"A past evolution is undeniable, a present evolution undemonstrable."
John A. Davison
Comment by John A. Davison — December 30, 2006 @ 4:31 pm