General Questions

k = -3/4 ln(1 – 4d/3)

“fast-X effect”: an expected increase in the rate of adaptive evolution on the X chromosome due to the fixation of recessive, beneficial mutations in hemizygous males.

“large-X effect”: the X is enriched for loci that cause hybrid incompatibilities, such as hybrid male sterility, suggesting that the X plays a disproportionately large role in speciation – at least in the evolution of postzygotic reproductive isolation.

Refers to situations where prolonged physical barriers impede gene flow between populations.

This might be most likely when a small part of a larger population becomes isolated, called peripatric speciation (because Ne is small => drift; think of a rare colonisation event of an island).

the process by which barriers to gene flow evolve between populations as a result of ecologically based divergent selection

The evolution of a new species from a surviving ancestral species while both continue to inhabit the same geographic region.

Pleiotropy is a property of an allele, not of a gene, allowing one allelic substitution to influence multiple traits, aiding speciation.

Reproductive isolation is strengthened by substituting the same alleles in the emerging daughter species, preventing recombination from breaking down associations.

Reproductive isolation is strengthened by substituting different alleles in the emerging daughter species.

Traits that contribute to prezygotic isolation, evolve under direct selection, and influence assortative mating, overcoming the antagonism between selection and recombination.