Roberts Natalie S, Mendelson Tamra C
Department of Biological Sciences University of Maryland, Baltimore County Baltimore MD USA.
Ecol Evol. 2020 Feb 12;10(5):2499-2512. doi: 10.1002/ece3.6076. eCollection 2020 Mar.
Reinforcement occurs when selection against hybrid offspring strengthens behavioral isolation between parental species and may be an important factor in speciation. Theoretical models and experimental evidence indicate that both female and male preferences can be strengthened upon secondary contact via reinforcement. However, the question remains whether this process is more likely to affect the preferences of one sex or the other. Males of polygynous species are often predicted to exhibit weaker preferences than females, potentially limiting the ability for reinforcement to shape male preferences. Yet, in darters (Percidae: ), male preference for conspecific mates appears to arise before female preferences during the early stages of allopatric speciation, and research suggests that male, but not female, preferences become reinforced upon secondary contact. In the current study, we aimed to determine whether the geographically widespread darter species exhibits a signature of reinforcement, by comparing the strength of preference for conspecific mates between populations that are sympatric and allopatric with respect to a close congener, . We examined the strength of preference for conspecifics for males and females separately to determine whether the preferences of one or both sexes have been strengthened by reinforcement. Our results show that both sexes of from sympatric populations exhibit stronger conspecific preferences than from allopatric populations, but that female preferences appear to be more strongly reinforced than male preferences. Results therefore suggest that reinforcement of female preferences may promote behavioral isolation upon secondary contact, even in a genus that is characterized by pervasive male mate choice.
当针对杂交后代的选择强化了亲本物种之间的行为隔离时，就会发生强化现象，这可能是物种形成的一个重要因素。理论模型和实验证据表明，通过强化，雌性和雄性的偏好都可以在二次接触时得到加强。然而，问题仍然存在，即这个过程是否更有可能影响某一性别的偏好。通常预测，一夫多妻制物种的雄性表现出的偏好比雌性弱，这可能会限制强化塑造雄性偏好的能力。然而，在镖鲈（鲈科： ）中，在异域物种形成的早期阶段，雄性对同种配偶的偏好似乎比雌性出现得更早，并且研究表明，在二次接触时，雄性而非雌性的偏好会得到强化。在当前的研究中，我们旨在通过比较与近缘物种 同域和异域分布的种群之间对同种配偶的偏好强度，来确定地理分布广泛的镖鲈物种 是否表现出强化的特征。我们分别检查了雄性和雌性对同种个体的偏好强度，以确定是某一性别的偏好还是两性的偏好都通过强化得到了加强。我们的结果表明，同域种群中的 的两性都比异域种群中的 表现出更强的同种偏好，但雌性偏好似乎比雄性偏好得到了更强的强化。因此，结果表明，即使在一个以普遍存在雄性配偶选择为特征的属中，雌性偏好的强化也可能在二次接触时促进行为隔离。
