The parallel evolution of phenotypes or traits within or between species provides important insight into the basic mechanisms of evolution. Genetic and genomic advances have allowed investigations into the genetic underpinnings of parallel evolution and the independent evolution of similar traits in sympatric species. Parallel evolution may best be exemplified among species where multiple genetic lineages, descended from a common ancestor, colonized analogous environmental niches, and converged on a genotypic or phenotypic trait. Modern North American caribou (Rangifer tarandus) originated from three ancestral sources separated during the Last Glacial Maximum (LGM): the Beringian–Eurasian lineage (BEL), the North American lineage (NAL), and the High Arctic lineage (HAL). Historical introgression between the NAL and the BEL has been found throughout Ontario and eastern Manitoba. In this study, we first characterized the functional differentiation in the cytochrome-b (cytB) gene by identifying nonsynonymous changes. Second, the caribou lineages were used as a direct means to assess site-specific parallel changes among lineages. There was greater functional diversity within the NAL despite the BEL having greater neutral diversity. The patterns of amino acid substitutions occurring within different lineages supported the parallel evolution of cytB amino acid substitutions suggesting different selective pressures among lineages. This study highlights the independent evolution of identical amino acid substitutions within a wide-ranging mammal species that have diversified from different ancestral haplogroups and where ecological niches can invoke parallel evolution.
Related Resources
Biting Flies and Activity of Caribou in the Boreal Forest
Resource Date:
2018
Organization
Genetic Influences on Male and Female Variance in Reproductive Success and Implications for the Recovery of Severely Endangered Mountain Caribou
Resource Date:
October
2018
Deciduous Tree Species Classification Using Object-Based Analysis and Machine Learning with Unmanned Aerial Vehicle Multispectral Data
Resource Date:
August
2017
Organization
Hierarchical Land Cover and Vegetation Classification using Multispectral Data Acquired from an Unmanned Aerial Vehicle
Resource Date:
February
2017
Evolutionary Reconstruction of Peary Caribou Supports the Presence of a Pleistocene Polar Refugium for a Large Mammal Species
Resource Date:
September
2017
Organization
Was this helpful?
|