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Hierarchy in adaptive radiation: A case study using the Carnivora (Mammalia)
Graham J Slater1, Anthony R Friscia2
1Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637.
Evolution; International Journal of Organic Evolution
|January 29, 2019
Summary
The early burst model of adaptive radiation shows strong support for dental evolution in Carnivora, but not for body size. Trait diversification appears hierarchical, with early bursts linked to higher-level niches.
Area of Science:
- Evolutionary Biology
- Paleontology
- Zoology
Background:
- Simpson's "early burst" model proposes rapid initial diversification in clades.
- Its prevalence across the tree of life remains debated despite empirical testing.
Purpose of the Study:
- Evaluate the "early burst" model in the mammalian order Carnivora.
- Investigate adaptive radiation across 14 ecomorphological traits and body mass.
Main Methods:
- Phylogenetic analyses of trait evolution.
- Bayesian analyses of evolutionary correlations.
Main Results:
- Strong support for early bursts in dental evolution, linked to dietary resource axes.
- Inconsistent support at the family level; no evidence for early bursts in size-related traits.
- Decoupling of size and dental evolution, influenced by dietary specialization.
Conclusions:
- Trait diversification unfolds hierarchically, with early bursts affecting higher-level niche traits.
- Early bursts may be restricted to traits like diet and macrohabitat use, influencing higher taxon origins.
- Previous studies might have missed early burst signals by focusing on low-level niche traits in shallow clades.
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