Museum of Comparative Zoology and Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA.
Smithsonian Tropical Research Institute, Balboa-Ancon, Panama.
Bioessays. 2021 May;43(5):e2100020. doi: 10.1002/bies.202100020. Epub 2021 Mar 9.
A fundamental question in biology is whether phenotypes can be predicted by ecological or genomic rules. At least five cases of convergent evolution of the crab-like body plan (with a wide and flattened shape, and a bent abdomen) are known in decapod crustaceans, and have, for over 140 years, been known as "carcinization." The repeated loss of this body plan has been identified as "decarcinization." In reviewing the field, we offer phylogenetic strategies to include poorly known groups, and direct evidence from fossils, that will resolve the history of crab evolution and the degree of phenotypic variation within crabs. Proposed ecological advantages of the crab body are summarized into a hypothesis of phenotypic integration suggesting correlated evolution of the carapace shape and abdomen. Our premise provides fertile ground for future studies of the genomic and developmental basis, and the predictability, of the crab-like body form.
生物学中的一个基本问题是表型是否可以通过生态或基因组规则来预测。在十足目甲壳动物中，已知至少有五种类似螃蟹的身体形态（宽而扁的形状，弯曲的腹部）的趋同进化案例，并且已经有 140 多年的历史被称为“癌变”。这种身体形态的反复丧失已被确定为“去癌变”。在回顾该领域时，我们提供了系统发育策略来包括了解甚少的群体，并提供了来自化石的直接证据，这将解决螃蟹进化的历史以及螃蟹内部表型变异的程度。我们将螃蟹身体的拟议生态优势总结为一个表型整合假说，表明甲壳形状和腹部的相关性进化。我们的前提为未来研究螃蟹体型的基因组和发育基础以及可预测性提供了肥沃的土壤。
