Sperm Sociality: Cooperation, Altruism, and Spite

Pizzari, Tommaso; Foster, Kevin R.

doi:10.1371/journal.pbio.0060130

Cited by 78 publications

(104 citation statements)

References 38 publications

Supporting

Mentioning

103

Contrasting

Order By: Relevance

“…These studies provide support for the notion that sperm morphology is under strong selection from sperm competition. However, reductions in sperm variance in response to sperm competition may be due to either selection for improved sperm production efficiency, leading to a reduction in developmental errors (Hunter & Birkhead 2002), or a reduction in genomic conflict between the evolutionary interests of the haploid sperm and the diploid male (Parker 1993, Parker & Begon 1993, Immler et al 2008, Pizzari & Foster 2008. Unfortunately, distinguishing between these two, though not mutually exclusive, hypotheses can be challenging.…”

Section: Variation In Sperm Morphologymentioning

confidence: 99%

“…Cooperation among sperm within a given male's ejaculate is another exciting area of research in sperm competition that deserves greater attention (Pizzari & Foster 2008, Higginson & Pitnick 2010. In a variety of species, sperm can form conjugates of two or more individuals, who collectively swim faster than can Sperm wars individual sperm (Hayashi 1998, Moore et al 2002, Fisher & Hoekstra 2010.…”

Section: Sperm Cooperationmentioning

confidence: 99%

See 1 more Smart Citation

Sperm wars and the evolution of male fertility

Simmons¹,

Fitzpatrick²

2012

Reproduction

306

343

View full text Add to dashboard Cite

Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.

show abstract

Section: Variation In Sperm Morphologymentioning

confidence: 99%

Section: Sperm Cooperationmentioning

confidence: 99%

Sperm wars and the evolution of male fertility

Simmons¹,

Fitzpatrick²

2012

Reproduction

306

343

View full text Add to dashboard Cite

show abstract

“…Behavioral traits of males to prevail in sperm competition include transferring larger ejaculates when more males are in the vicinity (15) and performing ''retaliatory'' copulations when the female with which a male is paired copulates with another male (14). Another tactic involves the behavior and morphology of the sperm themselves, with the sperm from a male linking together so that the group can swim more vigorously (16). The male can also use his own genitalia or a spermatophore to physically displace sperm from previous males that are present in the female (10, 17).…”

Section: Mechanisms Of Postcopulatory Sexual Selectionmentioning

confidence: 99%

“…The sperm of internally fertilizing species of fish and echinoids, which would seem to need less swimming ability, are nevertheless longer than those of external fertilizers in the same groups. In several vertebrate and invertebrate taxa sperm have traits such as hook-shaped heads that allow individual sperm cells to link up with each other at least temporarily; in several of these species the resulting collaborative groups may swim straighter or more rapidly (16). Groupings of this sort seem to correlate with competition between sperm from different males, rather than between sperm cells in the same ejaculate (16).…”

Section: Evolutionary Consequences Of Postcopulatory Selection Genitamentioning

confidence: 99%

See 1 more Smart Citation

Postcopulatory sexual selection: Darwin's omission and its consequences

Eberhard

2009

Proc. Natl. Acad. Sci. U.S.A.

173

155

View full text Add to dashboard Cite

In one of his few major oversights, Darwin failed to appreciate that male-male competition and sexual selection can continue even after copulation has begun. The postcopulatory equivalents of both direct male-male battles (sperm competition) and female choice (cryptic female choice) occur within the female's body. Recognition of this hidden, but intense, sexual competition provides new insights into a variety of fields. These include the hyperdiverse and paradoxically elaborate morphology of both sperm and male genitalia, the equally puzzling and elaborate morphology of nongenitalic male structures that are specialized to grasp and stimulate females, powerful manipulative effects of substances in male semen on female reproductive physiology, paradoxical male courtship behavior that occurs after copulation has already begun, variability in parental investments, and the puzzlingly complex and diverse interactions between sperm and female products that surround animal eggs and between male gametophytes and female tissues in flowering plants. Many bizarre traits are involved, including male genitalia that are designed to explode or fall apart during copulation leaving behind parts within the female, male genitalia that ''sing'' during copulation, potent seminal products that invade the female's body cavity and her nervous system to influence her behavior, and a virtual Kama Sutra of courtship behavior performed after rather than before genital coupling, including male-female dialogues during copulation.cryptic female choice ͉ sexually antagonistic coevolution P icture a pile of freshly-cut weeds at the sunny edge of a tropical forest. Metallic green flies dart and circle over it, chasing one another in short dashes. Your eye is caught when a chase ends as one fly grasps another in midair and the pair immediately lands on the pile of weeds. Their genitalia are already coupled, and the male immediately turns to face away from the female. After a few seconds, paradoxically (because he is already securely attached), he begins to court, rhythmically waving his colorful hind legs and tapping the female's abdomen. The courtship continues for a few minutes as the pair remains coupled, and then the flies separate. The female walks down into the pile where she lays eggs (her larvae will feed on the rotting vegetation), while the male rejoins the frenetic chases above the pile.Why would a male fly wait to court a female until after he has already achieved his evolutionary objective of copulating with her? The answer (recently worked out by a Brazilian graduate student, F. Barbosa, personal communication) had to wait for Ͼ100 years after Darwin's great book on sexual selection (1) that explained so many other aspects of male-female sexual interactions.

show abstract

Post‐copulatory Reproductive Strategies

Snook

Pizzari

2012

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

In most sexually reproducing organisms females obtain sperm from multiple males. Such widespread female promiscuity prolongs the operation of sexual selection after copulation, through the competition of the ejaculates of different males over fertilisation (sperm competition) and mechanisms by which females systematically bias the outcome of sperm competition (cryptic female choice – CFC). Post‐copulatory sexual selection can either consistently favour certain male or ejaculate phenotypes or certain combinations of male and female genotypes. Sperm competition and CFC drive the evolution of a diverse range of post‐copulatory strategies resulting in differential ejaculate allocation by males and differential sperm utilisation by females. The post‐copulatory reproductive strategies of each sex have considerable impact on the fitness of the opposite sex, giving rise to an intimate process of intersexual coevolution. The concept of post‐copulatory sexual selection is therefore a powerful heuristic tool to explain variation in individual fitness and the staggering variation in sexual strategies both across and within species. Key Concepts: Sexual selection, or intrasexual competition for mates and fertilisation, can continue after copulation when females mate with multiple males (polyandry). The post‐copulatory processes of sperm competition and cryptic female choice are equivalent to pre‐copulatory mate competition and female choice. Molecular and behavioural studies have demonstrated the female multiple mating is nearly ubiquitous and therefore post‐copulatory sexual selection is a major evolutionary force. Sperm competition occurs when the ejaculates of different males compete to fertilise the same set of eggs, and selects for male adaptations both to prevent and win such competition A male's relative share of paternity is increased through adaptations of sperm quantity and quality, in addition to behavioural, morphological and physiological adaptations in somatic traits. Cryptic female choice (CFC) refers to female‐driven biases in the outcome of sperm competition, which are repeatable within females. CFC and sperm competition are often difficult to distinguish because they can interact to bias sperm use. Females have a wide variety of adaptations that mediate CFC; examples include differential sperm ejection, spermicide, and differential maternal allocation. Patterns of CFC can either differ between different combinations of male and female genotypes, or be consistent among females sharing similar preferences. Post‐copulatory sexual selection can foster the maintenance of polymorphism and alternative reproductive strategies within a species. The post‐copulatory reproductive strategies of one sex can reduce the fitness of the other sex, reflecting sexual conflict over mating and fertilisation. Such conflict can fuel sexually antagonistic coevolution of post‐copulatory traits.

show abstract

Sperm Sociality: Cooperation, Altruism, and Spite

Abstract: The idea of subfertile or altogether infertile sperm seems an evolutionary paradox, so why have they evolved in a diverse set of species, from molluscs to mice? Understanding sperm sociality may provide the answer.

Cited by 78 publications

References 38 publications

Sperm wars and the evolution of male fertility

Sperm wars and the evolution of male fertility

Postcopulatory sexual selection: Darwin's omission and its consequences

Post‐copulatory Reproductive Strategies

Contact Info

Product

Resources

About