Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
Arthropod Struct Dev. 2021 Jul;63:101064. doi: 10.1016/j.asd.2021.101064. Epub 2021 Jun 4.
Architecture, like nests, burrows, and other types of fortresses, may have played an important role in the evolution of social life on land. However, few studies have examined architecture in organisms that transitioned from sea to land to test how and why architectural and morphological changes might have jointly impacted social evolution. Here I contrasted the shell architecture and body morphology of two of the phylogenetically most closely-related land versus sea species of hermit crab (the terrestrial hermit crab, Coenobita compressus, and the marine hermit crab, Calcinus obscurus), as well as the original builder of their shells (the gastropod, Nerita scabricosta). In contrast to the shells of gastropods and marine hermit crabs, only the shells of terrestrial hermit crabs were architecturally remodeled, with no columella inside for the occupants to grip upon to resist eviction. The bodies of terrestrial hermit crabs were also significantly more exposed outside the enlarged openings of their remodeled shells, whereas the substantially smaller-bodied marine hermit crabs were safeguarded deep within the recesses of their unremodeled shells. Ultimately, these changes in shell architecture and body morphology likely had consequences for social evolution on land, making conspecifics not only more dependent upon one another for homes, but also potentially easier to evict. Further changes in claw shape on land (with the claws of terrestrial hermit crabs becoming shorter, wider, and thicker) may have evolved to help offset their heightened danger of social eviction, acting as a more effective door against conspecifics.
建筑结构，如鸟巢、洞穴和其他类型的堡垒，可能在陆地生物的社会生活进化中发挥了重要作用。然而，很少有研究检验过从海洋过渡到陆地的生物中的建筑结构，以测试建筑结构和形态变化如何以及为何可能共同影响社会进化。在这里，我对比了两种亲缘关系最密切的陆生和海生寄居蟹（陆生寄居蟹 Coenobita compressus 和海洋寄居蟹 Calcinus obscurus）以及它们贝壳的原始制造者（腹足纲动物 Nerita scabricosta）的贝壳结构和身体形态。与腹足纲动物和海洋寄居蟹的贝壳不同，只有陆生寄居蟹的贝壳在结构上进行了改造，内部没有柱形物供居住者抓住以防止被驱逐。陆生寄居蟹的身体也明显更多地暴露在其改造后的贝壳的扩大开口之外，而体型较小的海洋寄居蟹则被安全地保护在其未改造贝壳的凹陷处。最终，贝壳结构和身体形态的这些变化可能对陆地的社会进化产生了影响，使得同种生物不仅更加依赖彼此的住所，而且更容易被驱逐。在陆地上，爪子形状的进一步变化（陆生寄居蟹的爪子变得更短、更宽、更厚）可能是为了帮助它们应对更高的社会驱逐风险而进化的，充当着更有效的抵御同种生物的“门”。
