Social Slime Molds Meet Their Match

摘要

Alleles of genes that code for altruistic behavior face an identity crisis. Such behaviors are costly, and alleles that cause them can spread only if the benefits of altruism are preferentially directed to individuals that also carry the helpful allele. In most cases, altruistic individuals rise to this challenge probabilistically: They help relatives because their close genetic relationship makes them the best bet for carrying an identical allele. But even relatives are not a sure thing, and the cost of errant helping behavior could be avoided if alleles for altruistic behavior could directly recognize themselves in other individuals.