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Experimental Manipulation of Body Size to Estimate Morphological Scaling Relationships in Drosophila
Published on: October 1, 2011
Accelerated body size evolution during cold climatic periods in the Cenozoic
Julien Clavel1, Hélène Morlon2
1Institut de Biologie de l'École Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, École Normale Supérieure, Paris Sciences et Lettres (PSL) Research University, F-75005 Paris, France clavel@biologie.ens.fr.
Summary
Climate change significantly impacts the evolution of body size in birds and mammals. Evolutionary rates are higher during cold periods, suggesting climate influences selective pressures.
Area of Science:
- Evolutionary Biology
- Paleoclimatology
- Comparative Phylogenetics
Background:
- The accumulation of ecological and morphological diversity over geological time is a key question in evolutionary biology.
- Adaptive radiation theory explains rapid phenotypic divergence due to biotic interactions but often overlooks abiotic influences.
- Previous studies on abiotic drivers of phenotypic evolution are limited to a few lineages or small clades.
Purpose of the Study:
- To develop a phylogenetic comparative framework for assessing how clade-wide phenotypic evolution rates vary with abiotic drivers.
- To test the influence of global average temperature trends on body size evolution in birds and mammals.
Main Methods:
- Developed a phylogenetic comparative framework.
- Applied the framework to comprehensive bird and mammal phylogenies.
- Utilized body size data for 9,465 extant species and Cenozoic global temperature trends.
Main Results:
- Body size evolution rates in birds and mammals are primarily driven by past climate.
- Evolutionary rates were unexpectedly higher during cold periods compared to warm periods across most groups.
- Climate's effect on body size evolution is a general feature of endotherm evolution.
Conclusions:
- Climate change, particularly temperature shifts, plays a major role in shaping species' evolution.
- Temperature influences evolutionary rates by modifying selective pressures, not solely through metabolic effects.
- Past climatic changes have significantly shaped species' evolution and will likely continue to do so in the future.
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