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06:24
Individual Culturing of Tigriopus Copepods and Quantitative Analysis of Their Mate-guarding Behavior
Published on: September 26, 2018
Ecological specialization in fossil mammals explains Cope's rule
P Raia1, F Carotenuto, F Passaro
1Dipartimento di Scienze della Terra, Università degli Studi Federico II, Largo San Marcellino 10, 80138 Napoli, Italy. pasquale.raia@unina.it
The American Naturalist
|February 11, 2012
Summary
Cope's rule, the trend of increasing body size in mammals, is driven by ecological specialization and niche expansion. Pulses of large-sized species origination during global cooling suggest independent selection for larger size, aligning with Bergmann's rule.
Area of Science:
- Paleontology
- Evolutionary Biology
- Mammalogy
Background:
- Cope's rule describes the evolutionary trend of increasing body size within lineages over geological time.
- Explanations for Cope's rule include passive diffusion and active selection for traits favoring larger body size.
Purpose of the Study:
- To analyze body size evolution in Cenozoic mammals using a phylogenetically informed approach.
- To investigate the drivers behind the observed trend of increasing body size.
Main Methods:
- Phylogenetically informed analysis of body size evolution in Cenozoic mammals.
- Examination of species replacement patterns within clades and their ecological traits.
Main Results:
- Body size significantly increases in most mammalian clades through the substitution of incumbent species by larger relatives.
- Newly evolved larger species exhibit smaller ranges and rarity, indicative of ecological specialization.
- Pulses of large-sized species origination correlate with periods of global cooling.
Conclusions:
- Cope's rule appears primarily driven by increasing ecological specialization and niche expansion, not solely active selection for larger size.
- Bergmann's rule, favoring larger body size in colder climates, may act independently but concurrently with Cope's rule during cooling events.
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