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dc.contributor.authorMcGlothlin, Joel W.en
dc.contributor.authorKobiela, Megan E.en
dc.contributor.authorWright, Helen V.en
dc.contributor.authorMahler, Luke D.en
dc.contributor.authorKolbe, Jason K.en
dc.contributor.authorLosos, Jonathan B.en
dc.contributor.authorBrodie, Edmund D. IIIen
dc.description.abstractOn microevolutionary timescales, adaptive evolution depends upon both natural selection and the underlying genetic architecture of traits under selection, which may constrain evolutionary outcomes. Whether such genetic constraints shape phenotypic diversity over macroevolutionary timescales is more controversial, however. One key prediction is that genetic constraints should bias the early stages of species divergence along “genetic lines of least resistance” defined by the genetic (co)variance matrix, G. This bias is expected to erode over time as species means and G matrices diverge, allowing phenotypes to evolve away from the major axis of variation. We tested for evidence of this signal in West Indian Anolis lizards, an iconic example of adaptive radiation. We found that the major axis of morphological evolution was well aligned with a major axis of genetic variance shared by all species despite separation times of 20–40 million years, suggesting that divergence occurred along a conserved genetic line of least resistance. Further, this signal persisted even as G itself evolved, apparently because the largest evolutionary changes in G were themselves aligned with the line of genetic least resistance. Our results demonstrate that the signature of genetic constraint may persist over much longer timescales than previously appreciated, even in the presence of evolving genetic architecture. This pattern may have arisen either because pervasive constraints have biased the course of adaptive evolution or because the G matrix itself has been shaped by selection to conform to the adaptive landscape.en
dc.description.sponsorshipNational Science Foundationen
dc.description.sponsorshipNSF:DEB 0519658en
dc.description.sponsorshipVirginia Techen
dc.description.sponsorshipUniversity of Virginiaen
dc.rightsCreative Commons Attribution 4.0 Internationalen
dc.subjectAdaptive radiationen
dc.subjectAnolis lizardsen
dc.subjectconvergent evolutionen
dc.subjectcovariance tensor analysisen
dc.subjectG matrixen
dc.subjectquantitative geneticsen
dc.titleAdaptive radiation along a deeply conserved genetic line of least resistance in Anolis lizardsen
dc.typeArticle - Refereeden
dc.contributor.departmentBiological Sciencesen
dc.title.serialEvolution Lettersen

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Creative Commons Attribution 4.0 International
License: Creative Commons Attribution 4.0 International