Random Mutations

[PhDP]

there are no mutations that have a general benefit. Genes wont increase in their frequency without selectional pressure.

 

Even if selection isn't there, random genetic drift will makes allele frequency increase or decrease. And some mutations does have spectacular effect, I was just reading an article by Harvey, he showed that the extraordinary radiation of teleost fishes (about 50% of all vertebrates) was probably fuelled by a whole-genome duplication, giving material for evolution (natural selection and drift). The dynamics of mutations is not very well known, but it's certainly a very important part of what's missing in today's theory of evolution.

 

Hurley, I., Hale, M.E. and Prince, V.E. 2005. Duplication events and the evolution of segmental identity. EVOLUTION & DEVELOPMENT 7:6, 556–567.

 

Group selection is not occurring.

 

"Naive group selection", it's not. But there's much evidences that at least some sort of group selection is occuring;

 

Gregory, T.R. 2004. Macroevolution, hierarchy theory, and the C-value enigma. PALEOBIOLOGY, 30(2), 179–202.

[jeskill]

Yes' date=' group selection is not occuring, as you said, individuals are selected out. Sometimes this selection is mediated by a single gene, thereby deleting itself from the genepool. But that is irrelevant for the further adaption or evolution of the population. The relevant aspect is, what genetic information remains in the pool after selection and what is its frequency and diversity. The manifestation (does that word fit here?) of evolutionary changes can first be seen in the following generations, and here we are on the population level. The individuals that survived didnt change, their genes didnt change. Life has to reproduce in order to change, and this is indeed reflected in the population.

[/quote']

 

I don't disagree with everything you're saying about evolution. But I think the "relevant aspect" of evolution depends not on how you view evolution, but on what kind of questions you, as a scientist, want to ask. Sure, there are certain questions that population ecologists can ask that can't be asked by people studying evolutionary genetics. And vice versa. Understanding mutations in terms of how, why and at what rate they occur is just as important as understanding how evolution affects populations.

 

I definitely disagree. Evolution doesnt happen for the benefit and detriment of anything, there are just mechanisms. There are no trends, purposes or final goals or something like that.

 

I didn't mean to imply that there is a purpose or goal. I could restate it to say, "evolution can occur when genotypes that have higher fitness reproduce more" but that's kind of redundant.

[qed]

I didn't mean to imply that there is a purpose or goal.

 

Sorry if i got you wrong.

 

I could restate it to say, "evolution can occur when genotypes that have higher fitness reproduce more" but that's kind of redundant.

 

Thats correct.

 

But I think the "relevant aspect" of evolution depends not on how you view evolution, but on what kind of questions you, as a scientist, want to ask. Sure, there are certain questions that population ecologists can ask that can't be asked by people studying evolutionary genetics. And vice versa. Understanding mutations in terms of how, why and at what rate they occur is just as important as understanding how evolution affects populations.

 

Absolutely. I think we have a consent.

 

I only wanted to point at the population level because a lot of people blind this out when they try to understand evolution and focus on single genes and mutations. I think we all agree that that is not sufficient in order to get the big picture.