Function, Evolution and Anatomy Research Lab, Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
Institute for Marine Biological Resources and Biotechnology (IRBIM), National Research Council, Messina, 98122, Italy.
Evolution. 2022 Sep;76(9):2020-2031. doi: 10.1111/evo.14575. Epub 2022 Jul 29.
The evolution of complex morphological structures can be characterized by the interplay between different anatomical regions evolving under functional integration in response to shared selective pressures. Using the highly derived humeral morphology of talpid moles as a model, here we test whether functional performance is linked to increased levels of evolutionary integration between humerus subunits and, if so, what the strength is of the relationship. Combining two-dimensional geometric morphometrics, phylogenetic comparative methods, and functional landscape modeling, we demonstrate that the high biomechanical performance of subterranean moles' humeri is coupled with elevated levels of integration, whereas taxa with low-performance values show intermediate or low integration. Theoretical morphs occurring in high-performance areas of the functional landscape are not occupied by any species, and show a marked drop in covariation levels, suggesting the existence of a strong relationship between integration and performance in the evolution of talpid moles' humeri. We argue that the relative temporal invariance of the subterranean environment may have contributed to stabilize humeral morphology, trapping subterranean moles in a narrow region of the landscape and impeding any attempt to reposition on a new ascending slope.
复杂形态结构的进化可以通过不同解剖区域之间的相互作用来描述，这些区域在功能整合的基础上进化，以应对共同的选择压力。利用滑跖蟾科鼹鼠高度特化的肱骨形态作为模型，我们在这里测试功能表现是否与肱骨亚单位之间增加的进化整合程度有关，如果有关，那么这种关系的强度如何。我们结合二维几何形态测量学、系统发育比较方法和功能景观建模，证明了地下鼹鼠肱骨的高生物力学性能与较高的整合程度相关，而性能值较低的类群则表现出中等或较低的整合程度。在功能景观的高性能区域中出现的理论形态没有被任何物种占据，并且表现出协变水平的明显下降，这表明在滑跖蟾科鼹鼠肱骨的进化中，整合和性能之间存在很强的关系。我们认为，地下环境的相对时间不变性可能有助于稳定肱骨形态，将地下鼹鼠困在景观的一个狭窄区域内，并阻碍它们在新的上升坡面上重新定位的任何尝试。
