Two mating groups of Polysphondylium pallidum, a dictyostelid cellular slime mold

Kawakami, Shin-ichi; Hagiwara, Hiromitsu

doi:10.1007/s102670200065

Cited by 7 publications

(1 citation statement)

References 14 publications

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“…Kawakami and Hagiwara found that P. pallidum strains that belonged to complementary mating types also differed in aspects, including fruiting body morphology, in their asexual life cycles, 115 indicating a more usual type of 'synergism'-mutually beneficial interactions between a pair of individuals belonging to different phenotypes. Moreover, it is an unusual example of genotypes switching roles, by giving rise to sexual dimorphism (in one context) and cooperating within a social group (in another context).…”

Section: Phenotypic Differences Among Individuals Of the Same Genotyp...mentioning

confidence: 99%

Social selection and the evolution of cooperative groups: The example of the cellular slime moulds

Nanjundiah

Sathe

2011

Integr. Biol.

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In social selection the phenotype of an individual depends on its own genotype as well as on the phenotypes, and so genotypes, of other individuals. This makes it impossible to associate an invariant phenotype with a genotype: the social context is crucial. Descriptions of metazoan development, which often is viewed as the acme of cooperative social behaviour, ignore or downplay this fact. The implicit justification for doing so is based on a group-selectionist point of view. Namely, embryos are clones, therefore all cells have the same evolutionary interest, and the visible differences between cells result from a common strategy. The reasoning is flawed, because phenotypic heterogeneity within groups can result from contingent choices made by cells from a flexible repertoire as in multicellular development. What makes that possible is phenotypic plasticity, namely the ability of a genotype to exhibit different phenotypes. However, co-operative social behaviour with division of labour requires that different phenotypes interact appropriately, not that they belong to the same genotype, or have overlapping genetic interests. We sketch a possible route to the evolution of social groups that involves many steps: (a) individuals that happen to be in spatial proximity benefit simply by virtue of their number; (b) traits that are already present act as preadaptations and improve the efficiency of the group; and (c) new adaptations evolve under selection in the social context--that is, via interactions between individuals--and further strengthen group behaviour. The Dictyostelid or cellular slime mould amoebae (CSMs) become multicellular in an unusual way, by the aggregation of free-living cells. In nature the resulting group can be genetically homogeneous (clonal) or heterogeneous (polyclonal); in either case its development, which displays strong cooperation between cells (to the extent of so-called altruism) is not affected. This makes the CSMs exemplars for the study of social behaviour.

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Section: Phenotypic Differences Among Individuals Of the Same Genotyp...mentioning

confidence: 99%