Lynn Margulis:
“According to present-day neo-Darwinian evolutionary theory, the only
source of novelty is claimed to be by incorporation of random mutations,
by recombination, gene duplication, and other DNA rearrangements. As
is emphasized by those using the term symbiogenesis, symbiosis analysis
contradicts these assertions by revealing “Lamarckian” cases of the inheritance
of acquired genomes” Lynn Margulis
John Maynard Smith:
“The relevance of symbiosis is that it affords a mechanism
whereby genetic material from very distantly related organisms
can be brought together in a single descendant”
Not currently focusing on evolution theory. Yet, your title bought me here.
I think that in this excerpt Lynn Margulis and John Maynard Smith do not write that endosymbiosis undermine in any way natural selection. They stress the fact that Neo-Darwinism was incomplete because it only took into account random mutations as a diversification factor.
Add endosymbiosis as a diversification factor and natural selection still work just fine. You can consider the endosymbiosis that became fixed as evolutionary events.
Thanks for your answer Denis. I agree with you. Thanks for your extract Kenneth, I am going to read it carefully.
My doubts come from the fact that horizontal gene transfer is a source of new genes and has a non-genealogical transmission (at least at the beginning). This might question the neo-Darwinian idea of a gradual process for the emergence of novel traits, but, as you pointed out, natural selection should still work well. I cannot stop thinking that natural selection needs heritaiblity of the trait to occur, and feel there is something dangerous in horizontal genes tranfer (or endosymbiosis)...
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