Calhim Sara, Lampe Helene M, Slagsvold Tore, Birkhead Tim R
Department of Animal & Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
Biol Lett. 2009 Feb 23;5(1):58-61. doi: 10.1098/rsbl.2008.0544.
Theories regarding the role of sexual selection on the evolution of sperm traits are based on an association between pre-copulatory (e.g. female preference) and post-copulatory (e.g. ejaculate quality) male reproductive traits. In tests of these hypotheses, sperm morphology has rarely been used, despite its high heritability and intra-individual consistency. We found evidence of selection for longer sperm through positive phenotypic associations between sperm size and the two major female preference traits in the pied flycatcher, Ficedula hypoleuca. Our results support the sexually selected sperm hypothesis in a species under low sperm competition and demonstrate that natural and pre-copulatory sexual selection forces should not be overlooked in studies of intraspecific sperm morphology evolution.
关于性选择在精子性状进化中作用的理论，是基于交配前（如雌性偏好）和交配后（如射精质量）雄性生殖性状之间的关联。在这些假说的检验中，尽管精子形态具有高遗传性和个体内一致性，但很少被使用。我们通过雄性斑姬鹟（Ficedula hypoleuca）精子大小与雌性两个主要偏好性状之间的正表型关联，发现了对更长精子进行选择的证据。我们的结果支持了低精子竞争物种中的性选择精子假说，并表明在种内精子形态进化研究中，自然选择和交配前性选择力量不应被忽视。
