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How long does evoluution take.
#11
RE: How long does evoluution take.
(November 25, 2018 at 8:20 am)Brian37 Wrote: Evolution is species specific.
It couldn't be otherwise.
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#12
RE: How long does evoluution take.
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.
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#13
RE: How long does evoluution take.
Depends on the species and the selective pressure. Here, it happens several times over 11 days.

https://www.smithsonianmag.com/smart-new...180960418/
If The Flintstones have taught us anything, it's that pelicans can be used to mix cement.

-Homer Simpson
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#14
RE: How long does evoluution take.
5-7 business days, unless you splurge and go with the expedited delivery.
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#15
RE: How long does evoluution take.
Evolution is based on the reproductive cycle of the creatures experiencing said evolution, right? Bacteria with a reproductive cycle of hours would experience more evolutionary chances in a year than, say, a grey whale.
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#16
RE: How long does evoluution take.
How long have you got?

Playing Cluedo with my mum while I was at Uni:

"You did WHAT?  With WHO?  WHERE???"
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#17
RE: How long does evoluution take.
(November 25, 2018 at 12:19 pm)Gawdzilla Sama Wrote: Evolution is based on the reproductive cycle of the creatures experiencing said evolution, right? Bacteria with a reproductive cycle of hours would experience more evolutionary chances in a year than, say, a grey whale.

I've been under that impression, but one thing stops me from embracing that explanation. Mutation rates are relatively constant, and not affected by rates of reproduction. So it doesn't seem as simple ultimately as more reproduction, more mutations (not saying that is your position, but that seems a logical way to interpret the relationship between reproductive frequency and mutations. Thinking about it now, I suspect the frequency of reproductive cycles likely simply amplifies differences in reproductive fitness, resulting in more efficient and therefore quicker selection, but I'm just spitballing).
[Image: extraordinarywoo-sig.jpg]
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#18
RE: How long does evoluution take.
Mammals generally have red-green color blindness, which leads to an inability to see the hunter orange as a distinctive color. The ancestors of mammals, though, did have more color receptors (and marsupials keep the full allotment). Primates acquired a third color receptor through gene duplication (not resurrection of the ancestral color detector).

So, to acquire color vision of the type required for deer to see orange would likely require a gene duplication and subsequent mutation. Gene duplication isn't an incredibly common thing, especially at a given locus and is certainly not the type of thing one should expect in a few generations. And even if that duplication happens, there is an additional mutation needed (which is probably not as difficult to get).

I'd assume if the duplication and mutation happened, they would spread fairly quickly given the utility in the modern populations. But don't expect such to happen any time soon.
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#19
RE: How long does evoluution take.
(November 25, 2018 at 2:51 pm)Jörmungandr Wrote:
(November 25, 2018 at 12:19 pm)Gawdzilla Sama Wrote: Evolution is based on the reproductive cycle of the creatures experiencing said evolution, right? Bacteria with a reproductive cycle of hours would experience more evolutionary chances in a year than, say, a grey whale.

I've been under that impression, but one thing stops me from embracing that explanation.  Mutation rates are relatively constant, and not affected by rates of reproduction.  So it doesn't seem as simple ultimately as more reproduction, more mutations (not saying that is your position, but that seems a logical way to interpret the relationship between reproductive frequency and mutations.  Thinking about it now, I suspect the frequency of reproductive cycles likely simply amplifies differences in reproductive fitness, resulting in more efficient and therefore quicker selection, but I'm just spitballing).
I wasn't aware that mutation rates are relatively constant. I do know that a mutation can happen at any time. The propagation of that mutation is dependent on reproductive rates.
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#20
RE: How long does evoluution take.
(November 25, 2018 at 2:51 pm)Jörmungandr Wrote:
(November 25, 2018 at 12:19 pm)Gawdzilla Sama Wrote: Evolution is based on the reproductive cycle of the creatures experiencing said evolution, right? Bacteria with a reproductive cycle of hours would experience more evolutionary chances in a year than, say, a grey whale.

I've been under that impression, but one thing stops me from embracing that explanation.  Mutation rates are relatively constant, and not affected by rates of reproduction.  So it doesn't seem as simple ultimately as more reproduction, more mutations (not saying that is your position, but that seems a logical way to interpret the relationship between reproductive frequency and mutations.  Thinking about it now, I suspect the frequency of reproductive cycles likely simply amplifies differences in reproductive fitness, resulting in more efficient and therefore quicker selection, but I'm just spitballing).


The reason why rate of reproduction is important is only mutations that occurs in viable reproductive cells matter.   A mutation that occur in your skin cell may give you skin cancer, but you can’t pass it on.  So it doesn’t matter if you live a long life and develop a million mutation in other parts of your body during your life.  None of them matter because if they were not in your egg cells, then you can not pass them onto your offspring.  Your offspring will receive from you a set of relatively prestine genes without any of the mutations that happened elsewhere in your body.

So you might argue if you lived a long life, then your egg cells individually also has a long time in which to accumulate mutations.  Well, not entirely true.   Mutations do occur in a fully formed cell that’s just sitting there.  But majority of the mutations in any cell occurs during cellular division, when the cell was first formed.    In human females the egg cells form only once, before you were born, and then stored and rationed out for use during your entire life.   So majority of the mutations you can possibly pass on to your offspring happens only once during your own embryo development.  Hence, amount of evolution through mutation that originate with the female is closely correlated the number of generations of fetuses, and not closely related to how long each generation lives or how many years lapse between generations.

This is a somewhat different mechanism for evolution through mutations that originated with man.   In man, unlike in woman, sperms are continuously produced through cell reproduction throughout the life of the man.  So each generation of new sperm cells contain all the mutations the gem cells developed since the last generation of species cells, plus all the mutations the gem cells acquired during all the previous generation of species cells, in addition to errors that crept in when the sperm cell itself is produced. So as a man get older, his sperm cells also contain progressively more mutations that can be passed on.

So men, particularly fertile older men, are mutation machines for the purpose of reproduction and evolution,  where as women tend to be genetically conservative for the purpose of reproduction and evolution, even though men and women accumulate mutations in other cells of their bodies at identical rates.

Another thing about the common colloquial image of evolution is if you develop a mutation that is beneficial to you then you have a higher chance of passing it on to your offspring’s.

Absolutely false.

The only mutation that develops in you that you can pass on has to be in your reproductive cells. Changes to the genome of your reproductive cells has zero possibility of affecting your personal chances of survival. The genome of your reproductive cells cannot affect any of your physical traits.

What mutations in your reproductive cells will do is to pass the mutation and cause it to express itself not in you but your offspring‘s. So it is upon your offspring‘s that survival of the fittest acts upon the consequences of the mutations that occurred in you.
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