| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
|
|---|
| Research Abstract |
Three problems in the interaction of genes and culture were investigated theoretically. First, the cogency of three hypotheses advanced to explain the observed association between adult lactose absorption and milk use in human populations was assessed on the basis of a coevolutionary population genetic model. Much stronger selection pressures than previously claimed are required for consistency of the culture historical and calcium absorption hypotheses. A difference in preference for milk of absorbers and malabsorbers is a critical factor. In particular, the cultural transmission coefficients must satisfy a certain inequality for the reverse cause hypothesis to hold. Second, we investigated the conditions under which a sign language may be preserved in a deaf population. Cultural transmission of a sign language across generations is complicated by the fact that a significant fraction of profound childhood deafness is inherited as a simple recessive trait. Assuming segregation at two unlinked loci, we showed that vertical transmission can serve as an important channel, provided there is strong assortative mating for deafness. Horizontal transmission was shown to be effective when deaf children are able to interact with many peers. This observation is especially pertinent if assortative meeting of deaf children occurs, for example, at schools for the deaf. Third, the coevolution of cultural transmission and paternal care was investigated using two-locus haploid and diploid population genetic models. Maternal care of offspring is the rule in mammals. 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 father to provide care rather than to desert his mate is more likely to evolve if his role in enculturation is especially important. If relia
|
