Divergent Evolution Of New Species Is Not Genetically Expensive

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Timshel

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http://www.science20.com/news_artic..._new_species_not_genetically_expensive-123576

A new paper in Cell Reports finds that it doesn't take a lot of genetic changes to spur the evolution of new species—even if the original populations are still in contact and exchanging genes.


Once evolutionary divergence happens, though, it evolves rapidly, ultimately leading to fully genetically isolated species.


To reveal genetic differences critical for speciation,the researchers analyzed the genomes of two closely related butterfly species, Heliconius cydno and H. pachinus, which only recently diverged. Occupying similar ecological habitats and able to interbreed, these butterfly species still undergo a small amount of genetic exchange.


The researchers found that this regular gene flow mutes genetic variants unimportant to speciation, allowing them to identify key genetic areas affected by natural selection. The butterfly species, they discovered, differed in only 12 small regions of their genomes, while remaining mostly identical throughout the rest. Eight of these coded for wing color patterning, a trait important for mating and avoiding predation, and under intense selection pressure, while the other four remain undescribed.
 
PostmodernProphet said:
wait, don't you mean the entire population of the species?......
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Why don't you elaborate so I can prove once again what a lying moron you are?

I never stated that all speciation events are of the entire population from an archaic form to a newer one. Most animals have shorter generations and smaller ranges which means evolution happens faster and there is more genetic isolation.
 
you have claimed that evolution involves the entire species (even though there are no examples of it anywhere).......are you now claiming something different?......
 
PostmodernProphet said:
you have claimed that evolution involves the entire species (even though there are no examples of it anywhere).......are you now claiming something different?......
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LOL, do you want to rephrase that?

I have provided many examples.

There are no examples of entire species not evolving. Can you provide any?
 
Professor Baxter said:
LOL, do you want to rephrase that?
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no, I want you to answer it without pretending I said something different than what I said.....

I have provided many examples.
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and yet strangely, none of them have ever made it into one of your posts.....

There are no examples of entire species not evolving. Can you provide any?
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did the entire population of bears turn into polar bears?.....did the entire population of butterflies turn into monarchs?......
 
PostmodernProphet said:
no, I want you to answer it without pretending I said something different than what I said.....


and yet strangely, none of them have ever made it into one of your posts.....


did the entire population of bears turn into polar bears?.....did the entire population of butterflies turn into monarchs?......
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It has been answered, repeatedly, and your questions are only becoming more stupid.

Are there any bears identical to the basal forms? Are there any species of bears that exists unchanged from archaic forms?

There are no examples of animals where the entire population has not evolved.
 
PostmodernProphet said:
did the entire population of bears turn into polar bears?.....did the entire population of butterflies turn into monarchs?......
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Just because all of a population didn't evolve in a single direction doesn't mean evolution "stopped happening". Modern grizzlies and brown bears have evolved from whatever mutual ancestor they had with polar bears.
 
Watermark VII said:
Just because all of a population didn't evolve in a single direction doesn't mean evolution "stopped happening". Modern grizzlies and brown bears have evolved from whatever mutual ancestor they had with polar bears.
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He seems to be having trouble understanding that a species could evolve into forms distinct from archaic forms without splitting into more than one species. It all stems from trying to explain to him that the multi regional hypothesis for human evolution and that it is possible though may not be likely in light of all the evidence.
 
Out of Africa: We all came out of Africa ~100k years ago and spread from there.
Multiregional: Different subpopulations evolved in different parts of the Earth and have diverged from each other over a much longer period of time.

Not too hard.
 
Professor Baxter said:
It has been answered, repeatedly, and your questions are only becoming more stupid.

Are there any bears identical to the basal forms? Are there any species of bears that exists unchanged from archaic forms?

There are no examples of animals where the entire population has not evolved.
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come child, stop pretending you don't understand the question and simply answer it....
 
Watermark VII said:
Just because all of a population didn't evolve in a single direction doesn't mean evolution "stopped happening". Modern grizzlies and brown bears have evolved from whatever mutual ancestor they had with polar bears.
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but that is exactly what the professor is arguing....that the entire population DID evolve in a single direction......I am simply asking him for an example of this happening other than his belief that it happened with humans.....I am not denying there are grizzlies and brown bears as well as polar bears, but I am pointing out that therefore there should be species one of modern humans and species two of modern humans and species three of modern humans, just as is the case with bears.....
 
PostmodernProphet said:
but that is exactly what the professor is arguing....that the entire population DID evolve in a single direction......I am simply asking him for an example of this happening other than his belief that it happened with humans.....I am not denying there are grizzlies and brown bears as well as polar bears, but I am pointing out that therefore there should be species one of modern humans and species two of modern humans and species three of modern humans, just as is the case with bears.....
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In the out of Africa hypothesis, our common ancestor wasn't that distant, and it's not surprising we haven't diverged enough for breeding to be impossible, and besides there's been a lot of migration and interbreeding since then regardless. I'm not sure how the multiregional hypothesis explains us not diverging more than we have, but not that many people believe in it anyway.
 
I suppose I can copypasta from wikipedia:

The term "multiregional hypothesis" was coined in the early 1980s by Milford H. Wolpoff and colleagues, who used the theory to explain regional similarities between archaic humans and modern humans in various regions, in what they called regional continuity.[2][3] Wolpoff proposed that the mechanism of clinal variation allowed for the necessary balance between both local selection and overall evolution as a global species, with Homo erectus, Neanderthals, Homo sapiens and other human forms as subspecies. This species arose in Africa two million years ago as H. erectus and then spread out over the world, developing adaptations to regional conditions. Some populations became isolated for periods of time, developing in different directions, but through continuous interbreeding, replacement, genetic drift and selection, adaptations that were an advantage anywhere on earth would spread, keeping the development of the species in the same overall direction while maintaining adaptations to regional factors. By these mechanisms, surviving local varieties of the species evolved into modern humans, retaining some regional adaptations but with many features common to all regions.[3]

That's how the multiregional proponents attempt to explain the lack of significant divergence.
 
PostmodernProphet said:
but that is exactly what the professor is arguing....that the entire population DID evolve in a single direction......I am simply asking him for an example of this happening other than his belief that it happened with humans.....I am not denying there are grizzlies and brown bears as well as polar bears, but I am pointing out that therefore there should be species one of modern humans and species two of modern humans and species three of modern humans, just as is the case with bears.....
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I am not arguing that different species of hominae evolved into homo sapien. I am arguing that it is possible that the entire population of the single species of homo evolved in the same direction.

Of course, it is. It is not even controversial that it is possible. Divergent evolution is less common.
 
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Watermark VII said:
In the out of Africa hypothesis, our common ancestor wasn't that distant, and it's not surprising we haven't diverged enough for breeding to be impossible, and besides there's been a lot of migration and interbreeding since then regardless. I'm not sure how the multiregional hypothesis explains us not diverging more than we have, but not that many people believe in it anyway.
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Right. What he is suggesting with the bears would be more like arguing that chimpanzees, gorillas and archaic homo all evolved into modern humans. That of course is not possible. They would have to be able to easily interbreed.

I have not argued that the multi regional hypothesis is correct, but that it is not out of the range of possibility. I don't care for the hypothesis emotionally because it has been abused by racists. That is not a good reason to reject it scientifically. For that, the dna evidence does not support it.
 
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