Results 11 to 20 of about 158,096 (183)
Selection for longer lived sperm within ejaculate reduces reproductive ageing in offspring [PDF]
Males produce numerous sperm in a single ejaculate that greatly outnumber their potential egg targets. Recent studies found that phenotypic and genotypic variation among sperm in a single ejaculate of a male affects the fitness and performance of the ...
Ghazal Alavioon +4 more
doaj +3 more sources
Intramale variation in sperm size: functional significance in a polygynous mammal [PDF]
Studies concerning the relationships between sperm size and velocity at the intraspecific level are quite limited and often yielded contradictory results across the animal kingdom.
José Luis Ros-Santaella +2 more
doaj +4 more sources
Background and Aims: Embryo aneuploidy is caused by many factors, including patient age, sperm quality and sperm selection method. There are several methods for selecting sperm, ICSI (intracytoplasmic sperm injection) and IMSI (intracytoplasmic ...
Reza Raharjo +3 more
doaj +1 more source
No evidence for pre-copulatory sexual selection on sperm length in a passerine bird. [PDF]
There is growing evidence that post-copulatory sexual selection, mediated by sperm competition, influences the evolution of sperm phenotypes. Evidence for pre-copulatory sexual selection effects on sperm traits, on the other hand, is rather scarce.
Jan T Lifjeld +7 more
doaj +1 more source
Sperm selection is an essential component of all assisted reproductive treatments (ARTs) and is by far the most neglected step in the ART workflow in regard to technological innovation.
Steven A. Vasilescu +4 more
doaj +1 more source
The birth of a healthy child in a married couple with a history of multiple unsuccessful attempts at ART by selecting sperm on oocyte-cumulus complexes. Case report [PDF]
In male infertility, couples must use assisted reproductive technologies with the intracytoplasmic sperm injection (ICSI) technique. A significant disadvantage of ICSI is bypassing natural selection barriers since selective processes in the female ...
Alina V. Chistyakova +5 more
doaj +1 more source
Sperm design and variation in the New World blackbirds (Icteridae) [PDF]
Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other
AF Malo +81 more
core +2 more sources
The evolution of sperm morphometry in pheasants [PDF]
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. +5 more
core +3 more sources
Postcopulatory sexual selection [PDF]
The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to ...
A Civetta +132 more
core +1 more source
Psychological and physiological adaptations to sperm competition in humans [PDF]
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

