Male size does not affect the strength of male mate choice for high-quality females in Drosophila melanogaster

Theory predicts that the strength of male mate choice should vary depending on male quality when higher-quality males receive greater fitness benefits from being choosy. This pattern extends to differences in male body size, with larger males often having stronger pre- and post-copulatory preferences than smaller males.We sought to determine whether large males and small males differ in the strength (or direction) of their preference for large, high-fecundity females using the fruit fly, Drosophila melanogaster. We measured male courtship preferences and mating duration to show that male body size had no impact on the strength of male mate choice; all males, regardless of their size, had equally strong preferences for large females. To understand the selective pressures shaping male mate choice in males of different sizes, we also measured the fitness benefits associated with preferring large females for both large and small males. Male body size did not affect the benefits that males r...

理论预测，当优质雄性从择偶行为中获得更高适合度收益时，雄性择偶强度应随雄性品质发生变化。这一规律同样适用于雄性体型差异：相较于体型较小的雄性，体型较大的雄性通常在交配前与交配后均表现出更强的择偶偏好。本研究以黑腹果蝇（Drosophila melanogaster）为实验对象，旨在探究不同体型的雄性对体型更大、繁殖力更高的雌性的择偶强度（或偏好方向）是否存在差异。我们通过测定雄性求偶偏好与交配时长，发现雄性体型对其择偶强度并无影响：无论体型大小，所有雄性对大型雌性均表现出同等强度的偏好。为厘清塑造不同体型雄性择偶行为的选择压力，我们还分别测定了大型与小型雄性偏好大型雌性所对应的适合度收益。结果显示，雄性体型并未影响雄性...