Two-Locus Haploid and Diploid Models for the Coevolution of Cultural Transmission and Paternal Care

Abstract

The coevolution of cultural transmission and paternal care is investigated using two-locus haploid and diploid population genetic models. Maternal care of offspring is the rule in mammals, whereas paternal involvement is often minimal. If the biological father also provides care and his continued presence facilitates the transfer of adaptive cultural information, then the conditions for the initial spread of a genetic capacity for cultural transmission are easily satisfied. Conversely, a genetic tendency for the biological father to provide care rather than to desert his mate is more likely to evolve if his role in enculturation is especially important. These predictions derived from the mathematically simpler haploid model are seen to hold approximately for the more realistic diploid model. If the reliability of paternity is low, so that faithful males often direct care and cultural information at unrelated infants, the evolution of cultural transmission and paternal care are both unlikely to occur. We speculate that the evolution of cultural transmission and the nuclear family may have been linked in the hominid line.