Problems with reinforcement

Problems with reinforcement - could view such hybrid zones...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Problems with reinforcement: other possible outcomes: fusion of the two populations because differentiation was sufficiently slight that selection against hybrids is weak relative to the gene flow between forms. extinction of one or the other of the two forms. Quite likely when there is selection against heterozygotes. In population genetic terms, equivalent to heterozygote disadvantage AA, Aa, aa with fitnesses 1,1-s,1, a metastable equilibrium Selection against hybrids within the zone of secondary contact only favors displacement in sympatry ; gene flow in from allopatry will swamp the effect. One
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: could view such hybrid zones as genetic canyons of lost alleles. Another important question: if selection against hybrids is the driving force for reproductive character displacement, how will the genes for the different components of isolation/recognition sweep through the allopatric regions of the two species ranges where there is no hybridization, hence no selection? Another allopatric model is the Peripatric model referring to populations surrounding the main part of the current species range. See fig. 16.5, pg 434....
View Full Document

Ask a homework question - tutors are online