Conservation and Convergence of Genetic Architecture in the Adaptive Radiation of Anolis lizards

• Published in: bioRxiv
• Main Authors: Mcglothlin, Joel W, Kobiela, Megan E, Wright, Helen V, Kolbe, Jason J, Losos, Jonathan B, Brodie, Edmund D
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 18.02.2021
• Subjects: Adaptive radiation; Anolis; Convergence; Evolution; Evolution & development; Phylogeny
• DOI: 10.1101/2021.02.18.431064

ABSTRACT The G matrix, which quantifies the genetic architecture of traits, is often viewed as an evolutionary constraint. However, G can evolve in response to selection and may also be viewed as a product of adaptive evolution. The evolution of similar G matrices in similar environments would suggest that G evolves adaptively, but it is difficult to disentangle such effects from phylogeny. Here, we use the adaptive radiation of Anolis lizards to ask whether convergence of G accompanies the repeated evolution of habitat specialists, or ecomorphs, across the Greater Antilles. We measured G in seven species representing three ecomorphs (trunk-crown, trunk-ground, and grass-bush). We found that the overall structure of G does not converge. Instead, the structure of G is well conserved and displays a phylogenetic signal. However, several elements of G showed signatures of convergence, indicating that some aspects of genetic architecture have been shaped by selection. Most notably, genetic correlations between limb traits and body traits were weaker in long-legged trunk-ground species, suggesting effects of recurrent selection on limb length. Our results demonstrate that common selection pressures may have subtle but consistent effects on the evolution of G, even as the overall pattern of genetic architecture remains conserved. Competing Interest Statement The authors have declared no competing interest. Footnotes * https://github.com/joelmcg/AnolisG * https://datadryad.org/stash/dataset/doi:10.5061/dryad.pt2g084