This complexity of venom composition, coupled with the fact that many species specialize on specific prey, likely result in selective pressures on venom characteristics, leading to the evolution of advantageous venom phenotypes and predatory behaviors [ 36].
This organization allows co-evolution of advantageous class Ia/TAP haplotypes.
It has been suggested that this ancestral organization of the MHC facilitated the co-evolution of advantageous class Ia and TAP haplotypes that conferred resistance to specific pathogens [ 20, 21].
The rate of evolution for selectively advantageous mutants, in contrast to neutral mutants, is dependent on both population size and selection pressure.
Recombination can play an important role in evolution by combining advantageous mutations and thereby assisting in their fixation [ 7, 14].
A therapy-induced, directed somatic evolution towards an advantageous phenotype would correspond to a Lamarckian scheme: a new, better 'adapted', inheritable state is induced by an environmental input (Mayr, 1972).
From the point of evolution, it is advantageous for the population to maintain a relative high degree of diversity in the MHC loci in the context of changing circumstance.
However, it seems likely that such differences do exist and that the extended periods of allopatric divergence between some of the trout species before human-mediated secondary contact and admixture would have facilitated the evolution of traits advantageous in a particular drainage.
A second possibility is that changes in agonist specificity were advantageous during evolution, i.e. that positive selection acted on some TAAR to recognize ligands other than the known mouse agonists.
So sex is important, indeed foundational for evolution, because it creates advantageous new genes that are immune to it.
