Female mate choice is a reproductive isolating barrier in Heliconius butterflies

AbstractIn sexually reproducing organisms, speciation involves the evolution of reproductive isolating mechanisms that decrease gene flow. Premating reproductive isolation, often the result of mate choice, is a major obstacle to gene flow between species because it acts earlier in the life cycle than other isolating barriers. While female choice is often considered the default mode in animal species, research in the butterfly genusHeliconius, a frequent subject of speciation studies, has focused on male mate choice. We studied mate choice byHeliconius cydno females by pairing them with either conspecific males or males of the closely related speciesHeliconius pachinus. Significantly more intraspecific trials than interspecific trials resulted in mating. Because male courtship rates did not differ between the species when we excluded males that never courted, we attribute this difference to female choice. Females also performed more acceptance behaviours towards conspecific males. Premating isolation between these two species thus entails both male and female mate choice, and female choice may be an important factor in the origin ofHeliconius species.

Source: Ethology - November 14, 2018 Category: Zoology Authors: Laura Southcott, Marcus R. Kronforst, S. Bertram Tags: RESEARCH PAPER Source Type: research