The Effects of Heterospecific Mating Frequency on the Strength of Cryptic Reproductive Barriers
Publication Date
9-1-2019
Document Type
Article
Organizational Units
College of Natural Science and Mathematics, Biological Sciences
Keywords
Conspecific sperm precedence, Cryptic reproductive barriers, Hybrid zone, Hybridization frequency, Post‐mating prezygotic barriers, Relative abundance, Speciation
Abstract
Heterospecific mating frequency is critical to hybrid zone dynamics and can directly impact the strength of reproductive barriers and patterns of introgression. The effectiveness of post‐mating prezygotic (PMPZ) reproductive barriers, which include reduced fecundity via heterospecific matings and conspecific sperm precedence, may depend on the number, identity and order of mates. Studies of PMPZ barriers suggest that they may be important in many systems, but whether these barriers are effective at realistic heterospecific mating frequencies has not been tested. Here, we evaluate the strength of cryptic reproductive isolation in two leaf beetles (Chrysochus auratus and C. cobaltinus) in the context of a range of heterospecific mating frequencies observed in natural populations. We found both species benefited from multiple matings, but the benefits were greater in C. cobaltinus and extended to heterospecific matings. We found that PMPZ barriers greatly limited hybrid production by C. auratus females with moderate heterospecific mating frequencies, but that their effectiveness diminished at higher heterospecific mating frequencies. In contrast, there was no evidence for PMPZ barriers in C. cobaltinus females at any heterospecific mating frequency. We show that integrating realistic estimates of cryptic isolation with information on relative abundance and heterospecific mating frequency in the field substantially improves our understanding of the strong directional bias in F1 production previously documented in the Chrysochus hybrid zone. Our results demonstrate that heterospecific mating frequency is critical to understanding the impact of cryptic post‐copulatory barriers on hybrid zone structure and dynamics, and that future studies of such barriers should incorporate field‐relevant heterospecific mating frequencies.
Copyright Date
9-1-2019
Copyright Statement / License for Reuse
All Rights Reserved.
Rights Holder
European Society for Evolutionary Biology
Provenance
Received from author
Language
English (eng)
Extent
13 pgs
Publication Statement
Copyright is held by the European Society for Evolutionary Biology. User is responsible for all copyright compliance.
Publication Title
Journal of Evolutionary Biology
Volume
32
Issue
9
First Page
900
Last Page
912
ISSN
1420-9101
Recommended Citation
Larson, E., Brassil, M. M., Maslan, J., Juarez, D., Lilagan, F., Tipton, H., ..., & Peterson, M. A. (2019). The effects of heterospecific mating frequency on the strength of cryptic reproductive barriers. Journal of Evolutionary Biology, 32(9), 900–912. DOI: 10.1111/jeb.13495