Endemic species flocks inhabiting ancient lakes, oceanic islands and other long‐lived isolated habitats are often interpreted as adaptive radiations. Yet molecular evidence for directional selection during species flocks radiation is scarce. Using partial transcriptomes of 64 species of Lake Baikal (Siberia, Russia) endemic amphipods and two nonendemic outgroups, we report a revised phylogeny of this species flock and analyse evidence for positive selection within the endemic lineages. We confirm two independent invasions of amphipods into Baikal and demonstrate that several morphological features of Baikal amphipods, such as body armour and reduction in appendages and sensory organs, evolved in several lineages in parallel. Radiation of Baikal amphipods has been characterized by short phylogenetic branches and frequent episodes of positive selection which tended to be more frequent in the early phase of the second invasion of amphipods into Baikal when the most intensive diversification occurred. Notably, signatures of positive selection are frequent in genes encoding mitochondrial membrane proteins with electron transfer chain and ATP synthesis functionality. In particular, subunits of both the membrane and substrate‐level ATP synthases show evidence of positive selection in the plankton species
Insights into the generation of diversity in both plants and animals have relied heavily on studying speciation in adaptive radiations. Russia's Lake Baikal has facilitated a putative adaptive radiation of cottid fishes (sculpins), some of which are highly specialized to inhabit novel niches created by the lake's unique geology and ecology. Here, we test evolutionary relationships and novel morphological adaptation in a piece of this radiation: the Baikal cottid genus,
- PAR ID:
- 10367118
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Molecular Ecology
- Volume:
- 31
- Issue:
- 1
- ISSN:
- 0962-1083
- Format(s):
- Medium: X Size: p. 238-251
- Size(s):
- p. 238-251
- Sponsoring Org:
- National Science Foundation
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