Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions

Abstract

which they are associated, were linked in complex ways with a variety of species extinctions, extirpations, translocations, and new modes of niche modification. Evaluating Pleistocene anthropogenic impacts remains challenging, but novel methods and approaches are providing solutions to long-standing problems posed by limited preservation and chronological resolution. New data link the geographic and demographic expansion of H. sapiens to fire regime change and transformations to plant community composition. For example, pollen and microcharcoal records indicate that the early colonists of New Guinea deliberately burned and disturbed tropical rainforests to promote the growth of useful plants, especially gap colonizers like yams (Dioscorea spp.), which have been identified from microscopic starch residues extracted from some of the region’s earliest stone tools (21). (For species other than H. sapiens, this manuscript employs common species names, although the scientific name for each species discussed is also provided at first mention. For humans, the scientific name is further specified when it is important to distinguish from other hominid species.) Vegetation burning also enhanced hunting opportunities by drawing game and other faunal resources to new plant growth. A human contribution to the shaping of early fire regimes has been demonstrated for Africa and, after human arrival, in Borneo, Australia, and the Americas (22–25). The human-mediated translocation of species now dates back to the Late Pleistocene. For example, the northern common cuscus (Phalanger orientalis), endemic to New Guinea, was transported to eastern Indonesia, the Solomon Islands, and the Bismarck Archipelago beginning ∼20–23 ka, becoming a key subsistence species (26, 27). Other taxa were also moved; together with a species of bandicoot (Echymipera kalubu) and the Admiralty cuscus (Spilocuscus kraemeri), the Canarium indicum tree was introduced to Manus by ∼13 ka, followed a few millennia later by the rat Rattus praetor (26). Translocation patterns mirror patterns of maritime obsidian exchange in Melanesia in the Late Pleistocene and Early Holocene (26). Evidence of human overexploitation has been suggested for some Late Pleistocene faunal sequences. Diverse archaeological assemblages, from Africa, Europe, and South Asia, for example, document the Late Pleistocene appearance of small, quick, and difficult-to-catch game, such