2008) In this context it is unfortunate that we do not yet under

2008). In this context it is unfortunate that we do not yet understand the ecological significance of the extinction of the regional Pleistocene megafauna. Humans and their dogs (domesticated elsewhere ~40 ka) are associated with the extinction or widespread extirpation of >20 species of mammals including proboscideans, rhinoceroses, hippopotamus, tapirs, hyaenas, giant pangolin, AG-881 giant panda, river dolphins, and the giant primates, Pongo and Gigantopithecus. LY3039478 mw Unfortunately, the events are still too poorly documented to discuss either causes or ecological consequences (Louys 2007; Louys et al. 2007; Corlett 2009a). However, the communities in which the extirpated species lived have not collapsed and for conservationists

the real worries are not the losses of individual species but the more far-reaching effects of ecosystem collapse. The best defense against such catastrophe in Southeast Asia is to reduce human population growth and the rate of

habitat conversion and create the largest possible array of protected areas (Sodhi and Brook 2006; Corlett 2009a; Berry et al. 2010). Reserve size is especially important for terrestrial communities like the montane forests that are expected selleck to shrink in size or disappear as the climate warms. Unfortunately, the reserves that we would recommend for today’s conditions are not the same as those we will need after 100 years of projected habitat loss and climate change (Lee and Jetz 2008). Human biogeography: growing threats to regional biodiversity and ecosystems Humans have been part of nature in Southeast Asia

for a very long time. Homo erectus walked out of Africa ~1.9 Mya and spread as far as China, Vietnam, Java and Flores. They lived as small bands of hunter-gatherers who made stone tools. We do not yet know what impact they had on Pleistocene vegetation and megafauna but they used fire for the last 800 ka. H. erectus was replaced in the last hundred thousand years by populations Glutamate dehydrogenase of H. sapiens that left Africa ~85 ka. H. sapiens followed the same coastal route to Southeast Asia, arriving ~75 ka and subsequently spread to China and Australia. There is little physical evidence of this history as sea levels 70–80 ka were 50–60 m below today’s (Fig. 3b) and the traces are now submerged. The genetic evidence, on the other hand, is strong and documents the exodus from Africa, the route taken, the origins of the surviving descendants of the first wave of beachcombers in Southeast Asia, and the current patterns of diverse population distribution and admixture (Oppenheimer 2004; Hill et al. 2006). Beginning at the end of the LGM, ~19 ka, the coastal populations would have been pushed slowly inland for 12,000 years as sea levels rose from −130 m to +2–5 m, 4,200 years ago. Corlett (2009a) has reviewed the subsequent ecological impacts of these humans. They began spreading up the river valleys and practiced swidden agriculture at least 5,000 years ago.

Comments are closed.