Evolutionary consequences of selected locus-specific variations in epistasis and fitness contribution in Kauffman's NK model

Mathematical analysis and computer simulations are used to evaluate three m odifications to Kauffman's NK model in an attempt to incorporate unexplored aspects of epistatic interaction between loci in genome evolution. Two mod ifications-one to the amount and the other to the distribution of epistatic interaction-further support Kauffman's conclusion that high levels of epis tatic interaction lead to a decrease in overall fitness of the genome. The third model, however, provides a condition under which increased epistatic interaction at certain loci results in higher genome fitness. (C) 1999 Acad emic Press.