An analysis using a large sample of species reported a relationship between levels of sperm competition and sperm size, but the relation did not remain significant after phylogenetic effects were taken into account [ 33 ]. For chimpanzees, on the other hand, sperm competition is a serious issue. Because female bats store sperm during hibernation, the need for sperm to survive inside the female reproductive tract for up to several months could imply that in bats sperm competition favours sperm traits which enhance their longevity, rather than their swimming speed. Proportion of time apart from partner, male sexual psychology, and sperm competition in humans Homo sapiens. On mammalian sperm dimensions. Thus, they cannot exclude other factors that could be playing a role at any stage after fertilization and during embryo development. Thank you for your interest in spreading the word on Biology Letters.
Promiscuity - an Evolutionary History of Sperm Competition (USA)
Therefore, and contrary to the conclusion by Gage and Freckleton [ 33 ], our analyses allow us to conclude that the relationship between sperm dimensions and sperm competition in mammals remains robust after adequately controlling for phylogenetic effects. Paperback , pages. Synopsis About this title Males are promiscuous and ferociously competitive. Relation between sperm competition and sperm dimensions in eutherian mammals. Sperm swimming velocity was also significantly associated with relative testes mass, but not with body mass Table 1 , Figure 2B. Please subscribe or login to access full text content. Jump to Other Articles:
Promiscuity: An Evolutionary History of Sperm Competition by Tim Birkhead
Sara Keeble rated it liked it Jul 05, All of our books with dust-jackets are shipped in fresh, archival-safe mylar protective sleeves. Acta Geneticae Medicae et Gemellologiae, 41 1 , 43 — 7. There is a trace of damp by the lower corner of the rear board and a section on either side of the rear flap fold. March Volume 14 , issue 3.
Craig Craig rated it liked it Nov 20, Relationship between mate guarding frequency and the unstandardized residuals of PC3 after accounting for the influence of lifestyle and collection variables , which describes ejaculates with a high concentration of sperm and sperm that do not move erratically. Discussion Our study tested the general hypothesis that among males there would be a negative relationship between the use of tactics for the engagement in and avoidance of sperm competition, by examining the relationship between mate guarding and ejaculate quality in humans. Aliquots of 2microliters of the semen sample were pipetted into each of the chambers of a pre-warmed Leja Standard Count 4 chamber slide which was placed onto a pre-warmed Hamilton Thorne HTM MiniTherm stage warmer set to 37 Celsius. Procedure i Laboratory visit Participants were first asked to read an information sheet and sign a consent form.