Abstract. Directional selection is often viewed as a transient force in macroevolution, with its signal eroded over time by stabilizing and fluctuating sel

Abstract. Since Darwin and Humboldt, researchers have sought to understand how species adapt to elevation. Although tropical reptiles are typically most di

Abstract. Large phylogenetic trees are often unbalanced near the root, with a species-depauperate lineage sister to a far more species-rich clade. The spec

Adaptive radiations generate remarkable morphological diversity, yet traits often diversify at different rates and modes, producing mosaic patterns of evolution. Modularity, the semiautonomous organization of traits, can shape how selection and ...

Snake embryos coil, but how and why they corkscrew remains unexplored. Weber et al. find that the embryos wind up clockwise via buckling of the rapidly elongating axial body against the slow-growing, ...

Why do humans rely on XY chromosomes to determine sex, while birds use ZW—and many reptiles use neither, letting temperature decide instead?

Sex chromosome evolution is among the most dynamic genomic innovations in vertebrates, yet why some lineages evolve XY while others evolve ZW remains unclear. Using chromosome-level genomes from 19 ge...

Gene expression analysis of pigment cells in snake and lizard embryos and comparison with fish and frog shows that progenitors follow different developmental paths in each species yet mature cells pre...

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The IUCN Species Survival Commission has published a Position Statement on the vital role of biological collections in biodiversity conservation: a formal acknowledgement that natural history museums,...

Vaughn et al. show that hurricanes drive parallel genomic selection signatures in island anoles. One candidate locus (hs6st1) is associated with rear toe length. CRISPR disruption reduces hindfoot ele...

Male-like plumage helps female hummingbirds escape social harassment.

Modern amphibians are characterized by an aquatic larval stage that ends abruptly with a period of widespread tissue remodeling (metamorphosis) upon transition to terrestrial adulthood. A transient la...