Sex bias in mammalian specimen collections

Researchers explore sex bias in fossil and museum collections of mammals. Many mammalian species have a 1:1 sex ratio at birth, but previous studies have shown that male specimens are overrepresented in the fossil records of mammoths. To determine whether the specimen records of other mammals exhibit a similar bias, Graham Gower, Alan Cooper, and colleagues used ancient DNA to genetically determine the sex of 186 Pleistocene bison and 91 Pleistocene brown bear fossils. The authors sampled the fossils from the field and museums in Europe and North America. Approximately 75% and 64% of the bison and bear specimens were identified as male, respectively. The authors also found that across most ancient and modern mammalian orders, male specimens outnumbered female specimens in collections belonging to the American Museum of Natural History, the Natural History Museum in London, the Smithsonian Institution National Museum of Natural History, and the Royal Ontario Museum. The authors suggest that larger male ranges may increase their fossilization potential. Moreover, sex biases in fossil and museum collections may be ubiquitous and could bias scientific analyses, according to the authors.

Article #19-03275: “Widespread male sex bias in mammal fossil and museum collections ,” by Graham Gower et al.

MEDIA CONTACT: Graham Gower, Lundbeck GeoGenetics Centre, GLOBE Institute, University of Copenhagen, DENMARK; tel: +45-53337050; email:

[email protected]

; Kieren J. Mitchell, University of Adelaide, AUSTRALIA;

[email protected]

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