The genetic basis of convergent evolution among three species of fishes

Date
2019-10-31
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Abstract
The genetic basis of convergent evolution can be identified by comparing changes in allele frequencies across multiple species under the same environmental conditions. Patterns of elevated genetic divergence among populations or reduced genetic diversity within populations that are shared among species are often inferred as the product of convergent local adaptation. However, there are several other evolutionary processes that can produce similar patterns, making it hard to infer if these genetic patterns are caused by local adaptation. This study attempted to identify genetic candidates for convergent evolution by comparing pooled whole-genome data among three species of fish. Due to unexpectedly high genetic divergence among populations the ninespine stickleback (Pungitius pungitius) had to be removed from the analysis. Meaning the genetic patterns of local adaptation could only be compared between the two remaining species of fish. No candidates of convergent evolution were identified between the threespine stickleback (Gasterosteus aculeatus) and tubesnout (Aulorhynchus flavidus), indicating that either these species are responding to the same environmental pressure with different genetic changes, or that some unidentified aspect of the environment is leading to divergent patterns of local adaptation. Overall, this study demonstrates some of the potential problems with using genome scans that can make it difficult to identify the genetic basis of convergent evolution.
Description
Keywords
Convergent Evolution, Population Genetics, Genomics
Citation
Reeve, J. (2019). The genetic basis of convergent evolution among three species of fishes (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.