Elevated extinction rates as a trigger for diversification rate shifts: early amniotes as a case study

Brocklehurst, Neil and Ruta, Marcello and Müller, Johannes and Fröbisch, Jörg (2015) Elevated extinction rates as a trigger for diversification rate shifts: early amniotes as a case study. Scientific Reports, 5 (17104). pp. 1-10. ISSN ISSN 2045-2322

Full content URL: http://www.nature.com/articles/srep17104

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Item Type:Article
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Abstract

Tree shape analyses are frequently used to infer the location of shifts in diversification rate within the Tree of Life. Many studies have supported a causal relationship between shifts and temporally coincident events such as the evolution of “key innovations”. However, the evidence for such relationships is circumstantial. We investigated patterns of diversification during the early evolution of Amniota from the Carboniferous to the Triassic, subjecting a new supertree to analyses of tree balance in order to infer the timing and location of diversification shifts. We investigated how uneven origination and extinction rates drive diversification shifts, and use two case studies (herbivory and an aquatic lifestyle) to examine whether shifts tend to be contemporaneous with evolutionary novelties. Shifts within amniotes tend to occur during periods of elevated extinction, with mass extinctions coinciding with numerous and larger shifts. Diversification shifts occurring in clades that possess evolutionary innovations do not coincide temporally with the appearance of those innovations, but are instead deferred to periods of high extinction rate. We suggest such innovations did not cause increases in the rate of cladogenesis, but allowed clades to survive extinction events. We highlight the importance of examining general patterns of diversification before interpreting specific shifts.

Keywords:Amniota, extinction, diversification, Carboniferous, Permian, Triassic, evolutionary innovation, JCOpen
Subjects:C Biological Sciences > C182 Evolution
C Biological Sciences > C300 Zoology
F Physical Sciences > F641 Palaeontology
C Biological Sciences > C181 Biodiversity
Divisions:College of Science > School of Life Sciences
ID Code:19664
Deposited On:24 Nov 2015 10:50

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