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Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer

Phenotypically cryptic lineages appear common in nature, yet little is known about the mechanisms that initiate and/or maintain barriers to gene flow, or how secondary contact between them might influence evolutionary trajectories. The consequences of such contact between diverging lineages depend o...

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Autores principales: Stewart, Kathryn A, Lougheed, Stephen C
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Ltd 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3867898/
https://www.ncbi.nlm.nih.gov/pubmed/24363891
http://dx.doi.org/10.1002/ece3.851
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author Stewart, Kathryn A
Lougheed, Stephen C
author_facet Stewart, Kathryn A
Lougheed, Stephen C
author_sort Stewart, Kathryn A
collection PubMed
description Phenotypically cryptic lineages appear common in nature, yet little is known about the mechanisms that initiate and/or maintain barriers to gene flow, or how secondary contact between them might influence evolutionary trajectories. The consequences of such contact between diverging lineages depend on hybrid fitness, highlighting the potential for postzygotic isolating barriers to play a role in the origins of biological species. Previous research shows that two cryptic, deeply diverged intraspecific mitochondrial lineages of a North American chorus frog, the spring peeper (Pseudacris crucifer), meet in secondary contact in Southwestern Ontario, Canada. Our study quantified hatching success, tadpole survival, size at metamorphosis, and development time for experimentally generated pure lineage and hybrid tadpoles. Results suggest that lineages differ in tadpole survival and that F(1) hybrids may have equal fitness and higher than average mass at metamorphosis compared with pure parental crosses. These findings imply hybrid early life viability may not be the pivotal reproductive isolation barrier helping to maintain lineage boundaries. However, we observed instances of tadpole gigantism, failure to metamorphose, and bent tails in some tadpoles from hybrid families. We also speculate and provide some evidence that apparent advantages or similarities of hybrids compared with pure lineage tadpoles may disappear when tadpoles are raised with competitors of different genetic makeup. This pilot study implies that ecological context and consideration of extrinsic factors may be a key to revealing mechanisms causing negative hybrid fitness during early life stages, a provocative avenue for future investigations on barriers to gene flow among these intraspecific lineages.
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spelling pubmed-38678982013-12-20 Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer Stewart, Kathryn A Lougheed, Stephen C Ecol Evol Original Research Phenotypically cryptic lineages appear common in nature, yet little is known about the mechanisms that initiate and/or maintain barriers to gene flow, or how secondary contact between them might influence evolutionary trajectories. The consequences of such contact between diverging lineages depend on hybrid fitness, highlighting the potential for postzygotic isolating barriers to play a role in the origins of biological species. Previous research shows that two cryptic, deeply diverged intraspecific mitochondrial lineages of a North American chorus frog, the spring peeper (Pseudacris crucifer), meet in secondary contact in Southwestern Ontario, Canada. Our study quantified hatching success, tadpole survival, size at metamorphosis, and development time for experimentally generated pure lineage and hybrid tadpoles. Results suggest that lineages differ in tadpole survival and that F(1) hybrids may have equal fitness and higher than average mass at metamorphosis compared with pure parental crosses. These findings imply hybrid early life viability may not be the pivotal reproductive isolation barrier helping to maintain lineage boundaries. However, we observed instances of tadpole gigantism, failure to metamorphose, and bent tails in some tadpoles from hybrid families. We also speculate and provide some evidence that apparent advantages or similarities of hybrids compared with pure lineage tadpoles may disappear when tadpoles are raised with competitors of different genetic makeup. This pilot study implies that ecological context and consideration of extrinsic factors may be a key to revealing mechanisms causing negative hybrid fitness during early life stages, a provocative avenue for future investigations on barriers to gene flow among these intraspecific lineages. Blackwell Publishing Ltd 2013-11 2013-10-23 /pmc/articles/PMC3867898/ /pubmed/24363891 http://dx.doi.org/10.1002/ece3.851 Text en © 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. http://creativecommons.org/licenses/by/2.5/ Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.
spellingShingle Original Research
Stewart, Kathryn A
Lougheed, Stephen C
Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title_full Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title_fullStr Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title_full_unstemmed Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title_short Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer
title_sort testing for intraspecific postzygotic isolation between cryptic lineages of pseudacris crucifer
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3867898/
https://www.ncbi.nlm.nih.gov/pubmed/24363891
http://dx.doi.org/10.1002/ece3.851
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