Relatedness within and between leks of golden-collared manakin differ between sexes and age classes

Several hypotheses have been advanced to explain the evolution of leks, a mating system in which males aggregate at display sites where females choose their mates. Only a small proportion of males obtain copulations, and why other males join the lek remains unexplained. One hypothesis has called kin selection into play: if juvenile males join leks where their relatives display and contribute to attract females to the lek, they can gain indirect fitness benefits. We investigated the genetic structure of eight leks of golden-collared manakin, a tropical Passerine. Adult court-holder males, females, and immature males were caught within lek boundaries and the geographical location of the courts was recorded. For court-holding males, within-lek relatedness among four leks was significantly higher than average across-lek relatedness. Courts of more closely related males were not spatially associated within leks. Relatedness among immature males was relatively lower, yet higher within than be...已有多项假说被提出，用以解释求偶场（lek）的演化——求偶场是指雄性聚集于展示位点、由雌性选择配偶的一类交配体系。仅有极少数雄性能够获得交配机会，而其余雄性为何仍会加入求偶场，这一问题至今尚未得到合理解释。其中一项假说引入了亲缘选择（kin selection）理论：若幼年雄性加入其亲属进行展示的求偶场，并协助吸引雌性前往该求偶场，便可获得间接适合度收益。本研究针对热带雀形目鸟类金领娇鹟（golden-collared manakin）的8个求偶场展开遗传结构分析。研究人员在求偶场范围内捕捉了占据求偶位点的成年雄性、雌性以及幼年雄性，并记录了各个求偶位点的地理位置。对于占据求偶位点的雄性而言，4个求偶场内部的雄性间亲缘关系显著高于跨求偶场的平均亲缘关系水平。亲缘关系更近的雄性所占据的求偶位点，在求偶场内部并未呈现空间聚集特征。幼年雄性间的亲缘关系相对较低，但求偶场内部的亲缘关系仍高于……