Research backs human role in extinction of mammoths, other mammals

http://www.eurekalert.org/pub_releases/2015-10/uow-rbh102315.php

Public Release: 26-Oct-2015
Research backs human role in extinction of mammoths, other mammals
University of Wyoming

Radiocarbon analysis of the decline and extinction of large mammals in the Americas lends support to the idea that hunting by humans led to the animals' demise -- and backs the generally accepted understanding of when humans arrived in, and how they colonized, the Western Hemisphere.

Those findings by University of Wyoming researchers are reported this week in an article published in the Proceedings of the National Academy of Sciences, a major scientific journal. The study was conducted by Professor Todd Surovell and graduate student Spencer Pelton in UW's Department of Anthropology; Professor Richard Anderson-Sprecher in the Department of Statistics; and Assistant Professor Adam Myers in the Department of Physics and Astronomy.

Their work supports a hypothesis forwarded in 1973 by well-known geoscientist Paul Martin that the chronology of the extinction of animals such as mammoths, mastodons, camels, horses and ground sloths in the Americas could be used to map the spread of humans through the New World.

"The heavy ecological footprint of human societies throughout prehistory is becoming increasingly apparent through a variety of environmental (indicators) independent of the archeological record," the researchers wrote. "Past human societies have disrupted ecological communities in dramatic ways for many tens, if not hundreds of thousands, of years."

•••••

A number of hypotheses have been forwarded to explain the extinction of those animals. The "overkill hypothesis" connects their demise directly to overhunting by humans, and that is supported by the north-to-south extinction trend observed in the new study.

"... (T)he north to south time-transgressive pattern is striking, and, barring significant new data, it would be difficult to reconcile this pattern with extinction hypotheses that invoke a single climatic, ecological or catastrophic extinction mechanism across the entirety of the Americas," the researchers wrote.

•••••