Disproportionate extinction of South American mammals drove the asymmetry of the Great American Biotic Interchange.
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pnas.2009397117.pdf
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Resource type
Journal article
Date published
October 5, 2020
Abstract
The interchange between the previously disconnected faunas of North and South America was a massive experiment in biological invasion. A major gap in our understanding of this invasion is why there was a drastic increase in the proportion of mammals of North American origin found in South America. Four nonmutually exclusive mechanisms may explain this asymmetry: 1) Higher dispersal rate of North American mammals toward the south, 2) higher origination of North American immigrants in South America, 3) higher extinction of mammals with South American origin, and 4) similar dispersal rate but a larger pool of native taxa in North versus South America. We test among these mechanisms by analyzing ∼20,000 fossil occurrences with Bayesian methods to infer dispersal and diversification rates and taxonomic selectivity of immigrants. We find no differences in the dispersal and origination rates of immigrants. In contrast, native South American mammals show higher extinction. We also find that two clades with North American origin (Carnivora and Artiodactyla) had significantly more immigrants in South America than other clades. Altogether, the asymmetry of the interchange was not due to higher origination of immigrants in South America as previously suggested, but resulted from higher extinction of native taxa in southern South America. These results from one of the greatest biological invasions highlight how biogeographic processes and biotic interactions can shape continental diversity.
Funder
| Funder name | Awards |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | PCEFP3_187012; FN-1749 - P400PB_186733 - P2ZHP3_174749 |
Svenska Forskningsrådet Formas | VR: 2019-04739 - 2017-04980 - 2017-03862 |
Deutsche Forschungsgemeinschaft | DFG FZT 118 |
Journal title
Proceedings of the National Academy of Sciences
Volume
117
Issue
42
Publisher
Proceedings of the National Academy of Sciences
Place of publication
Washington, D.C., US
ISSN
0027-8424
eISSN
1091-6490
Date accepted
August 29, 2020
Official URL
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In Copyright