Snakes and lizards (Squamata) are a diverse group, and represent one third of terrestrial vertebrates. Although both have tremendous morphological variation associated with feeding and locomotion, snakes show unique ecomorphological diversity and specialization. Writing in Science, Title et al. constructed a time-calibrated genomic phylogeny for 6,886 species of squamates that they use — together with field and museum data for diet, morphology and chemosensory processing — to assess the evolutionary dynamics of the group. Snakes show faster rates of evolution of morphological and ecological traits than lizards, and many of the differences between the two can be attributed to a major shift in the early evolutionary history of snakes that led to specialized predatory strategies. Although snakes use a broader range of food sources than lizards, snakes are more specialized at the species level and the authors find some evidence for conservatism of trophic niche, despite shifts and the expansion of snakes’ trophic niche during the Cenozoic. Morphological innovation and speciation are positively correlated: snakes have higher innovation in morphological traits and faster speciation rates than lizards. However, this correlation is attributed to just one or two points in the phylogeny (the origin of snakes or the origin of colubriform snakes), which makes it statistically very difficult to associate either innovation or faster speciation rate with individual traits such as chemosensory innovation, limb loss or body elongation. Altogether, this analysis shows how early and ongoing diversification of specialized predatory strategies in snakes shapes squamate diversity to this day.

Original reference: Science 383, 918–923 (2024)

蛇和蜥蜴（Squamata）是一个多样化的类群，占陆地脊椎动物的三分之一。尽管两者都具有与进食和运动相关的巨大形态变异，但蛇表现出独特的生态形态多样性和专业化。撰写《科学》、《标题》等。为 6,886 种有鳞动物构建了时间校准的基因组系统发育学，并结合现场和博物馆的饮食、形态和化学感应处理数据来评估该群体的进化动态。蛇的形态和生态特征的进化速度比蜥蜴更快，两者之间的许多差异可归因于蛇早期进化史的重大转变，导致了专门的捕食策略。尽管蛇比蜥蜴使用更广泛的食物来源，但蛇在物种层面上更加专业化，作者发现了一些营养生态位保守性的证据，尽管蛇的营养生态位在新生代期间发生了变化和扩张。形态创新和物种形成呈正相关：蛇比蜥蜴具有更高的形态特征创新和更快的物种形成速度。然而，这种相关性仅归因于系统发育中的一两个点（蛇的起源或游蛇的起源），这使得统计上很难将创新或更快的物种形成率与化学感应创新等个体特征联系起来。肢体丧失或身体伸长。总而言之，这项分析表明，蛇类的专门捕食策略的早期和持续多样化如何塑造了迄今为止的有鳞多样性。

原始参考文献： Science 383 , 918–923 (2024)