Phylogenetic evidence from freshwater crayfishes that cave adaptation is not an evolutionary dead‐end |
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Authors: | David B. Stern Jesse Breinholt Carlos Pedraza‐Lara Marilú López‐Mejía Christopher L. Owen Heather Bracken‐Grissom James W. Fetzner Jr. Keith A. Crandall |
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Affiliation: | 1. Computational Biology Institute, The George Washington University, Ashburn, Virginia 20147;2. Department of Biology, University of Florida, Gainesville, Florida;3. Licenciatura en Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México, México;4. Lab. Biología Evolutiva y Genética de Poblaciones, Universidad de Quintana Roo, Cozumel, México;5. Department of Biological Sciences, Florida International University, North Miami, Florida 33181;6. Section of Invertebrate Zoology, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania 15213‐4080;7. Department of Invertebrate Zoology, U.S. National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia 20013 |
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Abstract: | Caves are perceived as isolated, extreme habitats with a uniquely specialized biota, which long ago led to the idea that caves are “evolutionary dead‐ends.” This implies that cave‐adapted taxa may be doomed for extinction before they can diversify or transition to a more stable state. However, this hypothesis has not been explicitly tested in a phylogenetic framework with multiple independently evolved cave‐dwelling groups. Here, we use the freshwater crayfish, a group with dozens of cave‐dwelling species in multiple lineages, as a system to test this hypothesis. We consider historical patterns of lineage diversification and habitat transition as well as current patterns of geographic range size. We find that while cave‐dwelling lineages have small relative range sizes and rarely transition back to the surface, they exhibit remarkably similar diversification patterns to those of other habitat types and appear to be able to maintain a diversity of lineages through time. This suggests that cave adaptation is not a “dead‐end” for freshwater crayfish, which has positive implications for our understanding of biodiversity and conservation in cave habitats. |
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Keywords: | Caves crayfish diversification extinction habitat range size synthesis |
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