… then you get divergence, incomplete lineage sorting, and speciation.
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This is silly. If populations are not connected by gene flow, then they should be treated as different populations and analyzed separately. Fixation will happen independently in each population.
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We know this can happen with lots of selective pressure as the weaker guys are eliminated even though the population is not completely connected. Drift requires the goldilocks scenario. Can you make the case this is common?
A flask in Lenskis lab would do it but in the wild species get separated.
Make the case that what is common? You’re making very little sense again.
Would do what?
Selective pressure only applies to ~10% of the primate genome. Strong selective pressure can actually drive the fixation of neutral mutations that occur near a selected function. This is called genetic hitchhiking:
They sure do. What results is two new species, and different neutral mutations will reach fixation in each population after the speciation event.
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This is the 2nd time that you state a requirement for “fixing” coming from multiple incidents of the same mutation occurring in one population.
Where on earth do you get this language?
Evolution rarely discusses multiple iterations of mutation… happening over and over!
How do you know this?
About 10% of primate genomes show sequence conservation as evidenced by having fewer mutations than other sections of the genome and fewer than would be expected from neutral drift.
Does this have any specific location or is it spread around the genome? How is a mutation determined to be a mutation? Mismatch?
It is spread throughout the genome. It is even spread throughout a gene, with most of the sequence in introns lacking function and lacking sequence conservation.
Yep. It is the same logic as finding a fingerprint and concluding a finger made it. I discuss the evidence for mutations in this thread.
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How would you account for this conservation?
Negative selection of deleterious mutations.
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That makes sense. So sequence matters in introns?
Very little sequence in introns is functional. Splice sites are important for constructing mRNA, and there are a few functional genes in introns (e.g. micro-RNA), but the vast majority of introns lack function.
The binding spots at the splicing sites are important and depend on sequence as that’s how splicing sites are recognized by the splicing machinery of course, but there’s usually a lot of junk DNA (and therefore RNA) in the middle. Introns are huge, the splicing sites aren’t.