Evidence for a one-allele assortative mating locus.

Area of Science:

• Evolutionary biology
• Genetics
• Speciation research

Background:

• Theoretical models propose that speciation with gene flow can occur via a
• one-allele mechanism.
• This mechanism involves the spread of a single allele within diverging species, reducing subsequent hybridization.

Purpose of the Study:

• To provide direct genetic evidence for the
• one-allele mechanism
• in natural populations.
• To investigate the role of specific alleles in reproductive isolation and speciation.

Main Methods:

• Genetic analysis of Drosophila pseudoobscura and Drosophila persimilis.
• Experimental insertion of alleles conferring assortative mating into different species.
• Observation of the effects of these alleles on hybridization.

Main Results:

• Direct genetic evidence for the
• one-allele mechanism
• was found in Drosophila pseudoobscura.
• Alleles influencing assortative mating in D. pseudoobscura had similar effects when transferred to D. persimilis.
• This suggests the presence of relevant genetic variation for controversial speciation modes.

Conclusions:

• The study provides empirical support for theoretical models of speciation with gene flow.
• Genetic variation conducive to reinforcement and sympatric speciation exists in nature.
• The
• one-allele mechanism
• is a plausible driver of divergence under gene flow.