Evolution of pre-mating reproductive isolation among conspecific populations of the sea rock-pool beetle Ochthebius urbanelliae driven by reinforcing natural selection

How natural selection might be involved in speciation remains a fundamental question in evolutionary biology. When two or more species co-occur in the same areas, natural selection may favour divergence in mating traits. By acting in sympatric but not allopatric populations, natural selection can also affect mate choice within species and ultimately initiate speciation among conspecific populations. Here we address this potential effect in the sea rock-pool beetles Ochthebius quadricollis and O.urbanelliae. The two species, which inhabit the Mediterranean coasts, co-occurr syntopically in an area along the Italian Tyrrhenian coast and completed reproductive isolation by reinforcement. In this paper, through mating trials under laboratory conditions between conspecific populations, we found in O.quadricollis no deviations from random mating. Conversely, in O.urbanelliae, we found a clear pattern of pre-mating isolation between the reinforced populations sympatric with O.quadricollis and ...

自然选择如何参与物种形成（speciation）过程，始终是进化生物学领域的核心科学问题。当两个或多个物种在同一区域内共存时，自然选择可能会推动交配性状（mating traits）的分化。若自然选择仅作用于同域种群（sympatric population）而非异域种群（allopatric population），还可影响物种内部的配偶选择（mate choice），并最终启动同种种群（conspecific population）间的物种形成进程。本研究以海岩池甲虫（sea rock-pool beetles）*Ochthebius quadricollis*与*O.urbanelliae*为研究对象，探讨自然选择的这一潜在效应。该两物种均栖息于地中海沿岸，在意大利第勒尼安海沿岸的一处区域内同微生境共存，并通过强化作用（reinforcement）完成了生殖隔离（reproductive isolation）。本研究通过实验室条件下的同种种群交配实验发现，*O.quadricollis*未出现偏离随机交配（random mating）的情况。与之相反，在*O.urbanelliae*中，研究人员观察到与*O.quadricollis*同域分布的强化种群之间，存在显著的交配前生殖隔离（pre-mating isolation）模式，且……