Early humans linked to large-carnivore extinctions
Hominins could have triggered broad changes to the numbers and diversity of meat-eaters in Africa, researcher says.
by Jeff Tollefson (26 April 2012)
Animal lovers around the world know modern otters as cute, playful and unthreatening. But the mustelid’s giant cousins in ancient Africa may have engaged in a life-and-death competition with humanity’s ancestors — and come out on the losing end.
The demise of the gigantic ‘bear otter’ (Enhydriodon dikikae) was part of a broader decline in large-carnivore diversity in Africa, which accelerated around 2 million years ago — roughly the time that the first representatives of the genus Homo appeared on the scene. Lars Werdelin, a curator at the Swedish Museum of Natural History in Stockholm has been building a case that our forebears had something to do with the change. Although direct evidence of any causal connection is sorely lacking, Werdelin says, the transition in the carnivore fossil record coincides nicely with advances in tool-making and dietary shifts among early hominins.
“The way I see it, this is one of the first ways in which we manipulated our environment on a large scale,” says Werdelin, who presented his latest findings at a symposium on human evolution and climate change at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York. Werdelin argues that hominins may have competed indirectly with some of these carnivores by occupying prime habitat, thus forcing the animals to change their behavior without ever coming into direct contact with them. In some cases, the hominins may have out-competed carnivores directly by forcing them to surrender fresh kills. Regardless, the emergence of early humans could have cascaded through the food chain — ultimately wiping out many of Africa’s larger meat-eaters…
(read more: Nature)
(images via NovaTaxa: TR - Victor Leshyk; B - Cal. Academy of Sci.)