RE: How long does evoluution take.
November 25, 2018 at 10:36 am
(This post was last modified: November 25, 2018 at 10:55 am by Anomalocaris.)
I believe the rapid evolution in fox examples cited above involve a particular quick, but common, mechanism of evolution in mammals. The fox didn’t evolve entirely new genes for new features and behavior. Instead, over the generation of the Foxes in the experiments cited above, the timing of the expression or suppression of existing genes as the animal matured changed. Indeed Tameness in domestic animals is thought to primarily involve the delay and weakening of the expression of certain behavior influencing genes that are normally strongly expressed in wild animals as they reach adolescence, and allowing certain other genes to continue to be expressed that in wild populations would normally be suppressed when the animal reach adulescence.
But genes and behavior usually don’t have 1:1 mapping. A given gene often impact a range of behaviors and physical traits. Often a gene is selected for one of factors it favorably impacts. Other factors it affects just come along for the ride. So the genetic model of domestication described above is supported by the fact that adult domesticated animals often have other physical characteristics that in wild animals are associated with juvenile animals, but which could have no conceivable benefit to domestication.
I can imagine looking up might be a tendency that has a genetic basis, and are associated with a gene whose expression were suppressed as deers reached adulescence in the wild, before humans in trees started to threaten them. However, failure to or delay in the suppression of this gene when the animal reaches adulthood begin to confer survival advantages in wild deer populations once hunters started using hunting blinds in trees. So gradually more and more wild deers stop suppressing that behavior gene as the animals matures, resulting in more and more adult animals finding hunters tree blinds.
The development of hunter vest vision would seem to me to be somewhat different. I am not sure if deers have a suppressed color vision gene, or if the gene was lost all together during evolution of deers. If the gene was lost all together during the remotes past of deer evolution history, then The mechanism for quick evolution by changing the timing of expression and suppression of existing genes can not operate. Instead whole new genes would have to arise through a series of fortuitous mutations that together confers hunter vest vision. But individually can’t hurt or kill the bearer of the mutations. So in that case I think the chances that a wholly new hunter vest vision can be expected to be very long in coming.
But genes and behavior usually don’t have 1:1 mapping. A given gene often impact a range of behaviors and physical traits. Often a gene is selected for one of factors it favorably impacts. Other factors it affects just come along for the ride. So the genetic model of domestication described above is supported by the fact that adult domesticated animals often have other physical characteristics that in wild animals are associated with juvenile animals, but which could have no conceivable benefit to domestication.
I can imagine looking up might be a tendency that has a genetic basis, and are associated with a gene whose expression were suppressed as deers reached adulescence in the wild, before humans in trees started to threaten them. However, failure to or delay in the suppression of this gene when the animal reaches adulthood begin to confer survival advantages in wild deer populations once hunters started using hunting blinds in trees. So gradually more and more wild deers stop suppressing that behavior gene as the animals matures, resulting in more and more adult animals finding hunters tree blinds.
The development of hunter vest vision would seem to me to be somewhat different. I am not sure if deers have a suppressed color vision gene, or if the gene was lost all together during evolution of deers. If the gene was lost all together during the remotes past of deer evolution history, then The mechanism for quick evolution by changing the timing of expression and suppression of existing genes can not operate. Instead whole new genes would have to arise through a series of fortuitous mutations that together confers hunter vest vision. But individually can’t hurt or kill the bearer of the mutations. So in that case I think the chances that a wholly new hunter vest vision can be expected to be very long in coming.
