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Parental care as a game
Author(s) -
Yamamura N.,
Tsuji N.
Publication year - 1993
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1046/j.1420-9101.1993.6010103.x
Subject(s) - biology , paternal care , sex ratio , offspring , population , demography , reproductive strategy , zoology , evolutionary biology , genetics , reproduction , pregnancy , sociology
A new game model of parental care is presented where fitnesses of males and females depend on frequencies of care and no‐care strategies in the population, as well as strategies of individuals and those of their mates. Evolutionarily stable states (ESS) of biparental‐care ( BC ), female‐care ( FC ), male‐care ( MC ), and no‐care ( NC ) are represented as regions in a 3‐dimensional parameter space, comprising the ratio of the number of offspring raised by FC or MC to that by BC , the ratio of that by NC to that by FC or MC , and the sex ratio. ESSs are not necessarily uniquely determined: ESS regions of FC and MC overlap in parts, as well as those of BC and NC . In a region where none of the four states is ever an ESS, a polymorphism (a mixed state of care and no‐care strategies in one or both sexes) is stable. Although an asymmetry between prezygotic investment times of males and females results in the difference in sizes of the ESS regions of FC and MC , it is not responsible for determining whether FC or MC evolves from other modes of parental care as a result of slowly changing parameters. The key factor is the sex ratio of adults in the population. By a slightly modified model, it is also shown that paternity uncertainty at fertilization of eggs is highly important for evolution of FC .