Body size downgrading of mammals over the late Quaternary

2018/04/20 by Felisa A. Smith, Rosemary E. Elliott Smith, S. Kathleen Lyons +1 · 9 citations
Social Sciences · Environmental Science · Earth and Planetary Sciences · #Pleistocene-Era Hominins and Archaeology #Wildlife Ecology and Conservation #Evolution and Paleontology Studies

paper · doi:10.1126/science.aao5987

openalex publication_date 2018/04/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Since the late Pleistocene, large-bodied mammals have been extirpated from much of Earth. Although all habitable continents once harbored giant mammals, the few remaining species are largely confined to Africa. This decline is coincident with the global expansion of hominins over the late Quaternary. Here, we quantify mammalian extinction selectivity, continental body size distributions, and taxonomic diversity over five time periods spanning the past 125,000 years and stretching approximately 200 years into the future. We demonstrate that size-selective extinction was already under way in the oldest interval and occurred on all continents, within all trophic modes, and across all time intervals. Moreover, the degree of selectivity was unprecedented in 65 million years of mammalian evolution. The distinctive selectivity signature implicates hominin activity as a primary driver of taxonomic losses and ecosystem homogenization. Because megafauna have a disproportionate influence on ecosystem structure and function, past and present body size downgrading is reshaping Earth's biosphere.

Citations

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• The youngest occurrence of Hexaprotodon Falconer and Cautley, 1836 (Hippopotamidae, Mammalia) from South Asia with a discussion on its extinction
• Late quaternary biotic homogenization of North American mammalian faunas
• Collapse of terrestrial mammal food webs since the Late Pleistocene
• Late Pleistocene megafauna extinction leads to missing pieces of ecological space in a North American mammal community
• Holocene extinction [wikipedia]