 Thus, greater effort must be placed on integrative and interdisciplinary studies that explicitly illuminate how the causal mechanisms and functional outcomes of related processes operate at each level of biological organization while at the same time revealing the relations among the levels.This article caused a good deal of comment, and with analysis now extending to the problem of evolution in a contaminated world.Here they discuss how epigenetic outcomes at the level of both the individual organism and the evolution of the population has created ‘new species’.