Kin selection is thought to drive the evolution of cooperation and conflict, but the specific genes and genome-wide patterns shaped by kin selection are unknown. We identified thousands of genes associated with the sterile ant worker caste, the archetype of an altruistic phenotype shaped by kin selection, and then used population and comparative genomic approaches to study patterns of molecular...

Hypotheses for the evolution of human female life-history characteristics have often focused on the social nature of human societies, which allows women to share the burden of childcare and provisioning amongst other members of their kin group. We test the hypothesis that child health and survival probabilities will be improved by the presence of kin using a longitudinal database from rural Gam...

Animal behavior is often altruistic. In the frame of the theory of natural selection, altruism can only exist under specific conditions like kin selection or reciprocal cooperation. We show that reciprocal cooperation, which is generally invoked to explain non-kin altruism, requires very restrictive conditions to be stable. Some of these conditions are not met in many cases of altruism observed...

In "Testing the Kin Selection Theory: Who Controls the Investments?" Bert Hölldobler and Edward Osborne Wilson discussed the predictive power of kin selection theory, a theory about the evolution [3] of social behaviors. As part of Hölldobler and Wilson's 1990 book titled The Ants, Hölldobler and Wilson compared predictions about the reproductive practices of ants to data about the reproductive...

Why did Darwin fail to develop his insights on kin selection into a proper theory of social adaptation? One suggestion has been that his inadequate understanding of heredity kept the problem out of focus. Here, I determine whether it is possible to develop a quantitative theory of kin selection upon the assumption of blending inheritance. I find that, whilst Hamilton's rule of kin selection can...

Inclusive ¢tness theory predicts that altruism should often be directed towards reproductive relatives, but it is unclear whether individuals that are most likely to help or harm relatives are also most likely to identify kin in the ¢rst place. Here I show that species and sibships of spadefoot toad tadpoles (Spea bombifrons and S. multiplicata) that were most likely to produce an environmental...

In this paper I examine the intracultural variability of parental and alloparental caregiving among the Aka foragers of the Central African Republic. It has been suggested that maternal kin offer higher frequencies of allocare than paternal kin and that maternal investment in infants will decrease when alloparental assistance is provided. Behavioral observations were conducted on 15 eight- to t...

Tissue cultures of Phyllanthus tenellus Roxb. were maintained on modified MS to evaluate in vitro flowering under light of different qualities: white (control), blue, green, red, yellow, UV-A plus white and darkness; as well as different growth regulators at concentrations (μM): IBA 0.98, KIN 0.46, KIN 2.3, IBA 0.98 + KIN 0.46, IAA 1.14 + KIN 0.46. The events from vegetative to reproductive gro...

In social insects, workers trade personal reproduction for indirect fitness returns from helping their mother rear collateral kin. Colony membership is generally used as a proxy for kin discrimination, but the question remains whether recognition allows workers to discriminate between kin and nonkin regardless of colony affiliation. We investigated whether workers of the ant Formica fusca can i...

The theory of inclusive fitness has transformed our understanding of cooperation and altruism. However, the proximate psychological underpinnings of altruism are less well understood, and it has been argued that emotional closeness mediates the relationship between genetic relatedness and altruism. In this study, we use a real-life costly behaviour (travel time) to dissociate the effects of gen...