Burbrink Frank T, Ruane Sara, Rabibisoa Nirhy, Raselimanana Achille P, Raxworthy Christopher J, Kuhn Arianna
Department of Herpetology American Museum of Natural History New York City New York USA.
Life Sciences Section, Negaunee Integrative Research Center Field Museum of Natural History Chicago Illinois USA.
Ecol Evol. 2023 Jul 28;13(8):e10344. doi: 10.1002/ece3.10344. eCollection 2023 Aug.
Speciation rates vary substantially across the tree of life. These rates should be linked to the rate at which population structure forms if a continuum between micro and macroevolutionary patterns exists. Previous studies examining the link between speciation rates and the degree of population formation in clades have been shown to be either correlated or uncorrelated depending on the group, but no study has yet examined the relationship between speciation rates and population structure in a young group that is constrained spatially to a single-island system. We examine this correlation in 109 gemsnakes (Pseudoxyrhophiidae) endemic to Madagascar and originating in the early Miocene, which helps control for extinction variation across time and space. We find no relationship between rates of speciation and the formation rates of population structure over space in 33 species of gemsnakes. Rates of speciation show low variation, yet population structure varies widely across species, indicating that speciation rates and population structure are disconnected. We suspect this is largely due to the persistence of some lineages not susceptible to extinction. Importantly, we discuss how delimiting populations versus species may contribute to problems understanding the continuum between shallow and deep evolutionary processes.
物种形成速率在整个生命之树上差异很大。如果微观和宏观进化模式之间存在连续统一体，那么这些速率应该与种群结构形成的速率相关联。先前研究物种形成速率与进化枝中种群形成程度之间联系的研究表明，根据不同的类群，它们要么相关，要么不相关，但尚未有研究考察在空间上局限于单一岛屿系统的年轻类群中物种形成速率与种群结构之间的关系。我们对马达加斯加特有的、起源于中新世早期的109种宝石蛇（伪蝰科）进行了研究，这有助于控制时空上的灭绝变异。我们发现，在33种宝石蛇中，物种形成速率与空间上种群结构的形成速率之间没有关系。物种形成速率变化较小，但种群结构在不同物种间差异很大，这表明物种形成速率与种群结构是不相关的。我们怀疑这主要是由于一些不易灭绝的谱系的持续存在。重要的是，我们讨论了界定种群与物种如何可能导致理解浅层和深层进化过程之间连续统一体时出现问题。
