Deep histories in New Guinea: Insights from human genetics on local demography and social processes

Abstract

In this, the second of three linked chapters oriented to human biology—specifically, genetics and genomics—we selectively review and synthesise aspects of research in the discipline that shed light on the deep histories of New Guinea’s indigenous inhabitants. At >800,000 km2, the island is accounted the world’s second-largest, and its physiographical and ecological variety is extreme; its human inhabitants are likewise diverse in culture and language, and far from uniform in biology. Here we focus on this human biological variation and its implications for New Guinea’s deep histories. Since these histories predate modern boundaries, we draw on and integrate data from across the island. As with the broader canvas of our first chapter, so also here, the literature available for our review—conditioned as it is by extraordinary technical advances in genetics and genomics— is very much more informative than it would have been 30 years ago. We begin by looking, cautiously, through the lens of the ethnographic and linguistic present. We then review existing literature selectively, and with an emphasis on research since 1990. This takes us from the era of classical polymorphisms, through uniparental markers, to the present genomic age. We explore the interrelationships of selected language groups across western and eastern New Guinea and between highlands and lowlands in some fresh analyses, exploring the implications for ‘split times’ between groups, their population size dynamics over time, and their environmentally and socially structured demographic processes. We also discuss the still unresolved extent to which genetic and linguistic variation may mirror each other. As with our first chapter, we close by contemplating the prospect of many deep histories yet to be told in, and about, this extraordinarily diverse yet still under-researched island.