Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, Cidade Universitária, 05508-900 São Paulo, SP, Brazil
Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, Cidade Universitária, 05508-900 São Paulo, SP, Brazil.
Proc Biol Sci. 2017 Dec 20;284(1869). doi: 10.1098/rspb.2017.1775.
An increase in ecological opportunities, either through changes in the environment or acquisition of new traits, is frequently associated with an increase in species and morphological diversification. However, it is possible that certain ecological settings might prevent lineages from diversifying. Arboreality evolved multiple times in vipers, making them ideal organisms for exploring how potentially new ecological opportunities affect their morphology and speciation regimes. Arboreal snakes are frequently suggested to have a very specialized morphology, and being too large, too small, too heavy, or having short tails might be challenging for them. Using trait-evolution models, we show that arboreal vipers are evolving towards intermediate body sizes, with longer tails and more slender bodies than terrestrial vipers. Arboreality strongly constrains body size and circumference evolution in vipers, while terrestrial lineages are evolving towards a broader range of morphological variants. Trait-dependent diversification models, however, suggest similar speciation rates between microhabitats. Thus, we show that arboreality might constrain morphological evolution but not necessarily affect the rates at which lineages generate new species.
生态机会的增加，无论是通过环境变化还是新特征的获得，通常与物种和形态多样化的增加有关。然而，某些生态环境可能会阻止谱系多样化。树栖生活在毒蛇中多次进化，使它们成为探索潜在新生态机会如何影响它们的形态和物种形成机制的理想生物。树栖蛇类通常被认为具有非常特殊的形态，体型过大、过小、过重或尾巴过短可能对它们来说是一个挑战。通过特征进化模型，我们发现树栖毒蛇的体型正在向中间体型进化，尾巴更长，身体更细，与陆生毒蛇相比。树栖生活强烈限制了毒蛇的体型和周长进化，而陆生谱系则朝着更广泛的形态变异进化。然而，基于特征的多样化模型表明，微生境之间的物种形成率相似。因此，我们表明，树栖生活可能会限制形态进化，但不一定会影响谱系产生新物种的速度。
