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ABSTRACT Adaptive radiations are rich laboratories for exploring, testing, and understanding key theories in evolution and ecology because they offer spectacular displays of speciation and ecological adaptation. Particular challenges to the study of adaptive radiation include high levels of species richness, rapid speciation, and gene flow between species. Over the last decade, high‐throughput sequencing technologies and access to population genomic data have lessened these challenges by enabling the analysis of samples from many individual organisms at whole‐genome scales. Here we review how population genomic data have facilitated our knowledge of adaptive radiation in five key areas: (1) phylogenetics, (2) hybridization, (3) timing and rates of diversification, (4) the genomic basis of trait evolution, and (5) the role of genome structure in divergence. We review current knowledge in each area, highlight outstanding questions, and focus on methods that facilitate detection of complex patterns in the divergence and demography of populations through time. It is clear that population genomic data are revolutionising the ability to reconstruct evolutionary history in rapidly diversifying clades. Additionally, studies are increasingly emphasising the central role of gene flow, re‐use of standing genetic variation during adaptation, and structural genomic elements as facilitators of the speciation process in adaptive radiations. We highlight hybridization—and the hypothesized processes by which it shapes diversification—and questions seeking to bridge the divide between microevolutionary and macroevolutionary processes as rich areas for future study. Overall, access to population genomic data has facilitated an exciting era in adaptive radiation research, with implications for deeper understanding of fundamental evolutionary processes across the tree of life.
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This content will become publicly available on March 1, 2026
Key Adaptive Trait Promotes Contrasting Modes of Diversification in a Bivalve Clade
Abstract Siphons in bivalves have been postulated as a key adaptive trait, enabling modes of life inaccessible to asiphonate lineages, that afford better protection from predation and dislodgement, thereby enhancing their taxonomic diversification. To test the impact of siphons on diversity, we compared two bivalve clades with similar shell forms and life positions that differ in the presence/absence of this supposed key trait: the asiphonate Archiheterodonta (origin ~ 420 Myr ago) and the siphonate Veneridae (origin ~ 170 Myr ago). We measured three characters relevant to burrowing (shell length, cross-sectional area, and proportional shell volume) in these two groups, finding that siphonate venerids occupy more modes of life than archiheterodonts because they can live at a greater range of distances from the sediment–water interface, with the thinnest shells occurring in the deepest-burrowing groups. Asiphonate taxa have thicker shells, perhaps as a compensatory adaptation in response to the potential for exposure and attack because they are limited to shallower depths of burial. The lack of siphons may have impeded morphologic and taxonomic diversification in archiheterodonts. In contrast, siphons are consistent with a key adaptive trait in the Veneridae, evidently enabling taxonomic diversification into a greater range of morphologies.
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- Award ID(s):
- 2049627
- PAR ID:
- 10584967
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- Evolutionary Biology
- Volume:
- 52
- Issue:
- 1
- ISSN:
- 0071-3260
- Page Range / eLocation ID:
- 26 to 39
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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