Multiple Mating, Sperm Utilization, and Social Evolution

1982 ◽  
Vol 119 (2) ◽  
pp. 263-281 ◽  
Author(s):  
Robert E. Page, ◽  
Robert A. Metcalf
2013 ◽  
Vol 368 (1613) ◽  
pp. 20120046 ◽  
Author(s):  
Stephen M. Shuster ◽  
William R. Briggs ◽  
Patricia A. Dennis

Multiple mating by females is widely thought to encourage post-mating sexual selection and enhance female fitness. We show that whether polyandrous mating has these effects depends on two conditions. Condition 1 is the pattern of sperm utilization by females; specifically, whether, among females, male mating number, m (i.e. the number of times a male mates with one or more females) covaries with male offspring number, o . Polyandrous mating enhances sexual selection only when males who are successful at multiple mating also sire most or all of each of their mates' offspring, i.e. only when Cov ♂ ( m , o ), is positive. Condition 2 is the pattern of female reproductive life-history; specifically, whether female mating number, m , covaries with female offspring number, o . Only semelparity does not erode sexual selection, whereas iteroparity (i.e. when Cov ♀ ( m , o ), is positive) always increases the variance in offspring numbers among females, which always decreases the intensity of sexual selection on males. To document the covariance between mating number and offspring number for each sex, it is necessary to assign progeny to all parents, as well as identify mating and non-mating individuals. To document significant fitness gains by females through iteroparity, it is necessary to determine the relative magnitudes of male as well as female contributions to the total variance in relative fitness. We show how such data can be collected, how often they are collected, and we explain the circumstances in which selection favouring multiple mating by females can be strong or weak.


2019 ◽  
Author(s):  
Sam G. B. Roberts ◽  
Anna Roberts

Group size in primates is strongly correlated with brain size, but exactly what makes larger groups more ‘socially complex’ than smaller groups is still poorly understood. Chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) are among our closest living relatives and are excellent model species to investigate patterns of sociality and social complexity in primates, and to inform models of human social evolution. The aim of this paper is to propose new research frameworks, particularly the use of social network analysis, to examine how social structure differs in small, medium and large groups of chimpanzees and gorillas, to explore what makes larger groups more socially complex than smaller groups. Given a fission-fusion system is likely to have characterised hominins, a comparison of the social complexity involved in fission-fusion and more stable social systems is likely to provide important new insights into human social evolution


Author(s):  
Volodymyr Reznik

The article discusses the conceptual foundations of the development of the general sociological theory of J.G.Turner. These foundations are metatheoretical ideas, basic concepts and an analytical scheme. Turner began to develop a general sociological theory with a synthesis of metatheoretical ideas of social forces and social selection. He formulated a synthetic metatheoretical statement: social forces cause selection pressures on individuals and force them to change the patterns of their social organization and create new types of sociocultural formations to survive under these pressures. Turner systematized the basic concepts of his theorizing with the allocation of micro-, meso- and macro-levels of social reality. On this basis, he substantiated a simple conceptual scheme of social dynamics. According to this scheme, the forces of macrosocial dynamics of the population, production, distribution, regulation and reproduction cause social evolution. These forces force individual and corporate actors to structurally adapt their communities in altered circumstances. Such adaptation helps to overcome or avoid the disintegration consequences of these forces. The initial stage of Turner's general theorizing is a kind of audit, modification, modernization and systematization of the conceptual apparatus of sociology. The initial results obtained became the basis for the development of his conception of the dynamics of functional selection in the social world.


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