Paul L. Koch

TL;DR: Evidence now supports the idea that humans contributed to extinction on some continents, but human hunting was not solely responsible for the pattern of extinction everywhere, and suggests that the intersection of human impacts with pronounced climatic change drove the precise timing and geography of extinction in the Northern Hemisphere.

TL;DR: In this article, the authors explore the isotopic fidelity of different carbon and oxygen-bearing components from individual fossil skeletons of Holocene humans and late Pleistocene mastodons and mammoths.

TL;DR: A 4.6‰ decline in the δ13C of atmospheric CO2 is estimated at the onset of the Paleocene-Eocene Thermal Maximum, an abrupt global warming event ∼55.8 Ma, leading to better constraints on past greenhouse-gas perturbations.

TL;DR: Use of this concentration-weighted linear mixing model is recommended whenever the elemental concentrations vary substantially among the sources, which may occur in a variety of ecological and geochemical applications of stable isotope analysis.

TL;DR: Results from recent studies suggest that humans precipitated extinction in many parts of the globe through combined direct (hunting) and perhaps indirect (competition, habitat alteration) impacts, but that the timing and geography of extinction might have been different and the worldwide magnitude less, had not climatic change coincided with human impacts in many places.