I've been reading the chapter by Haig et al in The Genetics and Biology of Sexual Conflict. I think this chapter has them quite unclearly defined. Could anyone describe these two phenomenon more clearly than the chapter does? Real or hypothetical examples would be good to give clarification, and clarification of how they are distinct from sexual conflict and antagonism.

"Parental Conflict will refer to phenotypic interactions in which matrigenes and patrigenes prefer different outcomes"

"Parental Antagonism occurs when an allele has a relative advantage when inherited from one sex but a relative disadvantage when inherited from the other."


You may inherit a gene, which is actually detrimental to your (most efficient) functioning and hence has a cost (eg. gene for being small when food is available from tall trees). On the other hand, you may inherit a gene which has a benefit for you (gene for being tall with food available from tall trees).

Sexual Antagonism:

What’s good for the goose may not be good for the gander. Thistwist on an old proverb captures the notion of sexual antagonism.Traits that confer high fitness on geese (females) may confer lowfitness on ganders (males), and vice versa.

In sexually dimorphic species (like all common complex life), the evolution of males is usually decoupled from females. This is not as bad as it seems, as females and males may have different patterns of selection, different phenotypes of mutations all at the same time dodging pleiotropic effects. Hence mutations benefiting one sex will sometimes be deleterious to the other (i.e. their fitness effects are ‘sexually antagonistic’)

Sexual Conflict:

Males and females have divergent interests in reproduction that are rooted in anisogamy and lead to distinct roles, due to sexual antagonism. Sexual conflict occurs between the same or different genes, when there are different optima for a trait expressed in both sexes (intralocus conflict) or when there is conflict over the outcome of a male–female interaction (interlocus conflict).

Intralocus sexual conflicts are potentially very common. Researchers have found a strong positive genetic correlation between male and female fitness at the larval stage in the fruit fly (when interests of the males and females are essentially the same -> survive and grow), but a strong negative genetic correlation between adult male and female reproductive success (when the sexes are expected to have different genetic interests). This is possibly due to sexual antagonism.

Interlocus conflicts occur when there is conflict over the outcome of male–female interactions, so that the optimal outcome is different for the two sexes,as occurs in yellow dung fly mating behaviour. In a rare instance, wikipedia does a good job of explaining the example:

In the yellow dung fly Scathophaga stercoraria, females can be injured in the battles between males suitors. Males are selected to evolve traits for competitive ability that would increase their reproductive success, but females would evolve a set of antagonistic adaptations to reduce their chances of being injured in battles between the males. Therefore, there is an interlocus sexual conflict in males and females that could possibly lead to an "unresolvable evolutionary chase" when a novel trait in males increases their competitive ability while harming the females



Parental Antagonism:

An allele in a gene is said to be parentally antagonistic if it has an inclusive fitness benefit when derived from one parent (say the mother), but an fitness cost when derived from the other parent (in this case the father)

There are many different theories out there, but the gist of it is essentially some process creating an asymmetry between the genes that you inherit from your father and mother (patriGENIC and matriGENIC), that causes differential expression of alleles (silencing the other copy) [2]

Parental Conflict:

When parent-offspring relations in sexually reproducing species are viewed from the standpoint of the offspring as well as the parent, conflict is seen to be an expected feature of such relations. In particular, parent and offspring are expected to disagree over how long the period of parental investment should last, over the amount of parental investment that should be given, and over the altruistic and egoistic tendencies of the offspring as these tendencies affect other relatives. In addition, under certain conditions parents and offspring are expected to disagree over the preferred sex of the potential offspring. In general, parent-offspring conflict is expected to increase during the period of parental care, and offspring are expected to employ psychological weapons in order to compete with their parents. [7]


[1] Haig, David. "Parental antagonism, relatedness asymmetries, and genomic imprinting." Proceedings of the Royal Society of London. Series B: Biological Sciences 264.1388 (1997): 1657-1662.

[2] Patten, M. M., et al. "The evolution of genomic imprinting: theories, predictions and empirical tests." Heredity 113.2 (2014): 119-128.

[3] Patten, Manus M., and David Haig. "Maintenance or loss of genetic variation under sexual and parental antagonism at a sex‐linked locus." Evolution 63.11 (2009): 2888-2895.

[4] Normark, Benjamin B. "Perspective: maternal kin groups and the origins of asymmetric genetic systems—genomic imprinting, haplodiploidy, and parthenogenesis." Evolution 60.4 (2006): 631-642.

[5] Connallon, Tim, and Andrew G. Clark. "Evolutionary inevitability of sexual antagonism." Proceedings of the Royal Society of London B: Biological Sciences 281.1776 (2014): 20132123.

[6] Chapman, Tracey, et al. "Sexual conflict." Trends in Ecology & Evolution 18.1 (2003): 41-47.

[7] Trivers, Robert L. "Parent-offspring conflict." American zoologist 14.1 (1974): 249-264.

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  • $\begingroup$ This reply may be overly scientific and jargon riddled. If so give me a shout, and I'll try and make it more easier to understand. And also note that I have lifted out paragraphs from papers and stitched them together, and have duly supplied the references for further reading.I did this, because the seminal papers which these ideas have been published in are the best way to learn the same. $\endgroup$ – Rover Eye Apr 27 '15 at 17:13
  • $\begingroup$ No worries on that front - about defend a phd about intralocus sexual conflict! Thanks for the excellent looking answer, I'll give it a proper read tomorrow to see if I get it clear! (Expect either 15 points or a comment looking for clarification tomorrow!) $\endgroup$ – rg255 Apr 27 '15 at 19:25
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    $\begingroup$ Just noticed did I just necro this thread from last year...? $\endgroup$ – Rover Eye Apr 27 '15 at 19:29

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