Deep histories in New Guinea: Insights from genetics on human adaptation to malaria and diverse environments

Abstract

In this, the third of three linked chapters oriented to human biology—specifically, genetics and genomics—in New Guinea, we change focus from investigating ancestry to investigating adaptation. Given the slow rate of evolutionary adaptation, prevalent genes adaptive to particular environmental pressures indicate probable exposure to those pressures for many past generations. Indeed, they suggest that such pressures were—maybe still are—life-and-death matters. We begin this chapter by sketching the present and past range of environments that characterise New Guinea and may exert pressures on human survival and reproduction. Our main example—it could hardly be otherwise— is malaria. We review a number of the ‘antimalarial’ alleles prevalent in New Guinea. We present simple models designed to provide qualitative insights into the time depth of these adaptations and hence of malaria itself on the island. No other example matches malaria, but we review existing evidence surrounding some other pressures—prion disease, solar radiation, altitude, diet—as well as some health implications of New Guinean genetic variation more broadly. Show more