Evolutionary transitions in specialised mating strategies of Nephila spiders - adaption and constraint

总体而言，一夫一妻制是罕见而神秘的，但分类群中没有父亲照顾的雄性一夫一妻制尤其令人费解。独占一只雌性蜘蛛(一夫一妻制)是蜘蛛属蜘蛛祖先的雄性交配策略。这种行为策略与特殊的形态特征有关，这些特征限制了雄性重新交配的能力，即使性选择应该倾向于切换到一夫多妻制策略。在派生的NePhila物种中，这种垄断尝试不再成功，雄性在面对证明其特殊历史的形态限制时重新获得了重新交配的能力。在这个研究项目中，我们比较了两个NePhila物种的交配系统，代表了这种从一夫一妻制向一夫多妻制转变的两端。我们将研究(1)在精子竞争的背景下防御性和攻击性策略之间的权衡，(2)一夫多妻制如何与男性精子限制的限制相协调，以及(3)两性的交配前景和生殖特征如何与物种内和物种之间的环境条件相关。这一方法有望对形成交配系统进化的适应性过程和约束的相互作用产生重要而新颖的见解。

Monogamy is rare and enigmatic in general but monogamy of males in taxa without paternal care is particularly puzzling. Monopolisation of a single female (monogyny) Is the inferred ancestral male mating strategy in the spider genus Nephila. This behavioural strategy is associated with specialised morphological traits that limit males' capacity to re-mate, even if sexual selection should favour switching to a polygynous strategy, In derived Nephila species, such monopolisation attempts are no longer successful, and males have regained their re-matIng capacity in the face of morphological constraints that testify to their specialised past. In this research-project, we compare the mating systems of two Nephila species, representing opposite ends of this transition from monogyny to polygyny. We will Investigate (1) trade-offs between defensive and offensive strategies in a context of sperm competition, (2) how polygyny is reconciled with the constraint of male sperm limitation and (3), how mating prospects and reproductive traits in both sexes relate to environmental conditions within and between species. This approach promises to yield important and novel insights Into the interplay of adaptive processes and constraints in shaping the evolution of mating systems.