Results 11 to 20 of about 67,643 (303)

Sperm competition in humans: mate guarding behavior negatively correlates with ejaculate quality. [PDF]

PLoS ONE, 2014
In species where females mate with multiple males, the sperm from these males must compete to fertilise available ova. Sexual selection from sperm competition is expected to favor opposing adaptations in males that function either in the avoidance of ...
Samantha Leivers, Gillian Rhodes, Leigh W Simmons   +2 more
doaj   +1 more source

By hook or by crook? Morphometry, competition and cooperation in rodent sperm. [PDF]

PLoS ONE, 2007
BACKGROUND: Sperm design varies enormously across species and sperm competition is thought to be a major factor influencing this variation. However, the functional significance of many sperm traits is still poorly understood.
Simone Immler, Harry D M Moore, William G Breed, Tim R Birkhead   +3 more
doaj   +1 more source

Sperm competition selects for sperm quantity and quality in the Australian Maluridae.

PLoS ONE, 2011
When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm ...
Melissah Rowe, Stephen Pruett-Jones
doaj   +1 more source

Psychological and physiological adaptations to sperm competition in humans [PDF]

, 2005
Postcopulatory competition between males, in the form of sperm competition, is a widespread phenomenon in many animal species. The extent to which sperm competition has been an important selective pressure during human evolution remains controversial ...
Goetz, AT, Pound, N, Shackelford, TK
core   +2 more sources

Differences in the fatty-acid composition of rodent spermatozoa are associated to levels of sperm competition

Biology Open, 2015
Sperm competition is a prevalent phenomenon that drives the evolution of sperm function. High levels of sperm competition lead to increased metabolism to fuel higher sperm velocities.
Javier delBarco-Trillo, Rafael Mateo, Eduardo R. S. Roldan   +2 more
doaj   +1 more source

Variation in apical hook length reflects the intensity of sperm competition in murine rodents. [PDF]

PLoS ONE, 2013
BackgroundPost-copulatory sexual selection has been shown to shape morphology of male gametes. Both directional and stabilizing selection on sperm phenotype have been documented in vertebrates in response to sexual promiscuity.MethodologyHere we ...
Martin Šandera, Tomáš Albrecht, Pavel Stopka   +2 more
doaj   +1 more source

The evolution of sperm morphometry in pheasants [PDF]

, 2007
Postcopulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilisation are separated in time and sperm storage increases the duration
Birkhead, T.R., Immler, S., Lesobre, L., Roman, Y., Saint-Jalme, M., Sorci, G.   +5 more
core   +3 more sources

Sperm death and dumping in Drosophila [PDF]

, 2004
Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use.
A Civetta, A Civetta, A Cordoba-Aguilar, AG Clark, AS Gilchrist, AS Gilchrist, B Jenzer, BI Arthur, CSP Price, D Scott, FM Hunter, GA Parker, GJ Lefevre, GT Miller, H Alonzo-Pimentel, HDM Moore, JK DeVries, L Xue, LG Harshman, LW Simmons, LW Simmons, M Otronen, MH Gromko, MH Gromko, MR Wheeler, S Pitnick, T Pizzari, TR Birkhead, WB Heed, WG Eberhard   +29 more
core   +1 more source

Sperm competition risk drives rapid ejaculate adjustments mediated by seminal fluid

eLife, 2017
In many species, males can make rapid adjustments to ejaculate performance in response to sperm competition risk; however, the mechanisms behind these changes are not understood.
Michael J Bartlett, Tammy E Steeves, Neil J Gemmell, Patrice C Rosengrave   +3 more
doaj   +1 more source

Apical Sperm Hook Morphology Is Linked to Sperm Swimming Performance and Sperm Aggregation in Peromyscus Mice

Cells, 2021
Mammals exhibit a tremendous amount of variation in sperm morphology and despite the acknowledgement of sperm structural diversity across taxa, its functional significance remains poorly understood. Of particular interest is the sperm of rodents.
Kristin A. Hook, Lauren M. Wilke, Heidi S. Fisher   +2 more
doaj   +1 more source