Every form of behavior is shaped by trial and error. Such stepwise adaptation can occur through individual learning or through natural selection, the basis of evolution. Since the work of Maynard Smith and others, it has been realized how game theory can model this process. Evolutionary game theory replaces the static solutions of classical game theory by a dynamical approach centered not on the concept of rational players but on the population dynamics of behavioral programs. In this book the authors investigate the nonlinear dynamics of the self-regulation of social and economic behavior, and of the closely related interactions among species in ecological communities. Replicator equations describe how successful strategies spread and thereby create new conditions that can alter the basis of their success, i.e., to enable us to understand the strategic and genetic foundations of the endless chronicle of invasions and extinctions that punctuate evolution. In short, evolutionary game theory describes when to escalate a conflict, how to elicit cooperation, why to expect a balance of the sexes, and how to understand natural selection in mathematical terms.

 Comprehensive treatment of ecological and game theoretic dynamics
 Invasion dynamics and permanence as key concepts
 Explanation in terms of games of things like competition between species

/pdf/evolutionary-games-and-population-dynamics-pax1uk4ywa.pdf

Evolutionary games and population dynamics

General Themes: G.A. Parker, Sperm Competition and the Evolution of Ejaculates: Towards a Theory Base. A.P. Moller, Sperm Competition and Sexual Selection. W.G. Eberhard, Female Roles in Sperm Competition. J. Wright, Paternity and Paternal Care. Taxonomic Treatments: L.F. Delph and K. Havens, Pollen Competition in Flowering Plants. D.R. Levitan, Sperm Limitation, Gamete Competition and Sexual Selection in External Fertilizers. N.K. Michiels, Mating Conflicts and Sperm Competition in Simultaneous Hermaphrodites. B. Baur, Sperm Competition in Molluscs. M.A. Elgar, Sperm Competition and Sexual Selection in Spiders and Other Arachnids. L.W. Simmons and M.T. Siva-Jothy, Sperm Competition in Insects: Mechanisms and the Potential for Selection. C.W. Petersen and R.R. Warner, Sperm Competition in Fishes. T.R. Halliday, Sperm Competition in Amphibians. M. Olsson and T. Madsen, Sexual Selection and Sperm Competition in Reptiles. T.R. Birkhead, Sperm Competition in Birds: Mechanisms and Function. D.A. Taggart, W.G. Breed, P.D. Temple-Smith, A. Purvis, and G. Shimmin, Reproduction, Mating Strategies and Sperm Competition in Marsupials and Monotremes. M. Gomendio, A.H. Harcourt, and E.R.S. Roldan, Sperm Competition in Mammals. T.R. Birkhead and A.P. Moller, Sperm Competition, Sexual Selection and Different Routes to Fitness. Index.

Sperm competition and sexual selection

The aim of this review is to consider the potential benefits that females may gain from mating more than once in a single reproductive cycle. The relationship between non-genetic and genetic benefits is briefly explored. We suggest that multiple mating for purely non-genetic benefits is unlikely as it invariably leads to the possibility of genetic benefits as well. We begin by briefly reviewing the main models for genetic benefits to mate choice, and the supporting evidence that choice can increase offspring performance and the sexual attractiveness of sons. We then explain how multiple mating can elevate offspring fitness by increasing the number of potential sires that compete, when this occurs in conjunction with mechanisms of paternity biasing that function in copula or post-copulation. We begin by identifying cases where females use pre-copulatory cues to identify mates prior to remating. In the simplest case, females remate because they identify a superior mate and 'trade up' genetically. The main evidence for this process comes from extra-pair copulation in birds. Second, we note other cases where pre-copulatory cues may be less reliable and females mate with several males to promote post-copulatory mechanisms that bias paternity. Although a distinction is drawn between sperm competition and cryptic female choice, we point out that the genetic benefits to polyandry in terms of producing more viable or sexually attractive offspring do not depend on the exact mechanism that leads to biased paternity. Post-copulatory mechanisms of paternity biasing may: (1) reduce genetic incompatibility between male and female genetic contributions to offspring; (2) increase offspring viability if there is a positive correlation between traits favoured post-copulation and those that improve performance under natural selection; (3) increase the ability of sons to gain paternity when they mate with polyandrous females. A third possibility is that genetic diversity among offspring is directly favoured. This can be due to bet-hedging (due to mate assessment errors or temporal fluctuations in the environment), beneficial interactions between less related siblings or the opportunity to preferentially fertilise eggs with sperm of a specific genotype drawn from a range of stored sperm depending on prevailing environmental conditions. We use case studies from the social insects to provide some concrete examples of the role of genetic diversity among progeny in elevating fitness. We conclude that post-copulatory mechanisms provide a more reliable way of selecting a genetically compatible mate than pre-copulatory mate choice. Some of the best evidence for cryptic female choice by sperm selection is due to selection of more compatible sperm. Two future areas of research seem likely to be profitable. First, more experimental evidence is needed demonstrating that multiple mating increases offspring fitness via genetic gains. Second, the role of multiple mating in promoting assortative fertilization and increasing reproductive isolation between populations may help us to understand sympatric speciation.

Why do females mate multiply? A review of the genetic benefits.

Prevalence of cooperation within groups of selfish individuals is puzzling in that it contradicts with the basic premise of natural selection. Favoring players with higher fitness, the latter is key for understanding the challenges faced by cooperators when competing with defectors. Evolutionary game theory provides a competent theoretical framework for addressing the subtleties of cooperation in such situations, which are known as social dilemmas. Recent advances point towards the fact that the evolution of strategies alone may be insufficient to fully exploit the benefits offered by cooperative behavior. Indeed, while spatial structure and heterogeneity, for example, have been recognized as potent promoters of cooperation, coevolutionary rules can extend the potentials of such entities further, and even more importantly, lead to the understanding of their emergence. The introduction of coevolutionary rules to evolutionary games implies, that besides the evolution of strategies, another property may simultaneously be subject to evolution as well. Coevolutionary rules may affect the interaction network, the reproduction capability of players, their reputation, mobility or age. Here we review recent works on evolutionary games incorporating coevolutionary rules, as well as give a didactic description of potential pitfalls and misconceptions associated with the subject. In addition, we briefly outline directions for future research that we feel are promising, thereby particularly focusing on dynamical effects of coevolutionary rules on the evolution of cooperation, which are still widely open to research and thus hold promise of exciting new discoveries.

http://www.matjazperc.com/publications/BioSystems_99_109.pdf

Coevolutionary games--a mini review.

We study the evolution of cooperation in the framework of evolutionary game theory, adopting the prisoner's dilemma and snowdrift game as metaphors of cooperation between unrelated individuals. In sharp contrast with previous results we find that, whenever individuals interact following networks of contacts generated via growth and preferential attachment, leading to strong correlations between individuals, cooperation becomes the dominating trait throughout the entire range of parameters of both games, as such providing a unifying framework for the emergence of cooperation. Such emergence is shown to be inhibited whenever the correlations between individuals are decreased or removed. These results are shown to apply from very large population sizes down to small communities with nearly 100 individuals.

/pdf/scale-free-networks-provide-a-unifying-framework-for-the-1twffak3u9.pdf

Scale-free networks provide a unifying framework for the emergence of cooperation.

Sperm are produced in astronomical numbers compared with eggs, and there is good evidence that sperm competition is the force behind the evolution of many tiny sperm. However, sperm production inevitably has costs. Recent research shows that male ejaculate expenditure is dynamic in both time and space, and that males are sensitive to risks of sperm competition and can vary ejaculate size accordingly. We focus on studies showing that males assess mating status and relative fecundity of females, and reveal that modulation of ejaculate investment by males can sometimes result in sperm limitation for females.

Sperm competition, male prudence and sperm-limited females

Preface 1. General Introduction 2. Theory I: Hamilton's Rule and the Evolutionary Limits of Selfishness 3. Theory II: Phenotypic Models of Sublethal sibling Competition 4. Theory III: Fatal Sibling Competition 5. An Introduction to Sibling Rivalry in Birds 6. Supply, Demand, and Defendability 7. Parent-Offspring Conflict I: The Battleground 8. Conflict Resolutions I: Begging Scrambles 9. Conflict Resolutions II: begging as an Hones Signal 10. Conflict Resolutions III: Clutch Size and Sexual Conflicts 11. Tests of Parents-Offspring Conflict Vs. Collaboration 12. Sibling Rivalry in Birds 13. Sibling Rivalry in Mammals 14. Sibling Rivalry in Vertberate Ecthotherms 15. Sibling Rivalry in Invertebrates 16. Sibling Rivalry in Plants 17. Epilogue Literature Cited

The Evolution of Sibling Rivalry

Evolutionary games in which two males mate with the same female are examined by using an evolutionarily stable strategy (ESS) approach. These prospective models of competitive ejaculation seek ESS sperm numbers for cases when sperm competition obeys the \`raffle principle'. In a \`fair raffle', each male's fertilization probability equals his sperm number divided by the total sperm number in the female tract. In a loaded raffle, one male's sperm are \`devalued' relative to his competitor, e.g. a sperm from the second male to mate counts as only (say) half of a ticket in the fertilization lottery compared with one of the first male's sperm. The models assume that there is a trade-off between effort spent on sperm and effort spent on obtaining matings, and that fitness is the product of number of matings and the expected gain from each one. In a general sense, ESS sperm numbers increase with the probability that two males mate with the same female, and decrease with the degree of unfairness in the raffle. However, the ESS depends critically on the information available to the two competitors, and whether they occupy roles (of first or second to mate) randomly or non-randomly. If males \`know' whether they are the first or the second to mate, but these roles are assigned randomly, sperm numbers should be equal for the two males whether the raffle is fair or unfair. If roles are not random, so that (say) a given male tends to be first to mate, sperm numbers will not be equal unless the raffle is a fair one. In a loaded raffle, the male whose sperm are devalued should compensate by expending a greater reproductive effort on sperm. If sperm costs are equal for the two males, then the male in the favoured role should produce less sperm, but nevertheless achieves higher paternity because of the loading in the raffle. If sperm costs are asymmetric for the two roles, in a fair raffle the male that can produce sperm more cheaply ejaculates more sperm (and hence experiences higher paternity) although he expends less reproductive effort on sperm production.

Sperm Competition Games: Raffles and Roles

https://www.cell.com/current-biology/pdf/S0960-9822(03)00939-4.pdf

Spermatozoal traits and sperm competition in Atlantic salmon: relative sperm velocity is the primary determinant of fertilization success.

https://bilder.buecher.de/zusatz/20/20768/20768534_lese_1.pdf

Geoffrey A. Parker

Papers

Sperm competition, male prudence and sperm-limited females

The Evolution of Sibling Rivalry

Sperm Competition Games: Raffles and Roles

Spermatozoal traits and sperm competition in Atlantic salmon: relative sperm velocity is the primary determinant of fertilization success.

Why are there so many tiny sperm? Sperm competition and the maintenance of two sexes.