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Updated: May 15, 2025
04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
899
The diffused evolutionary dynamics of morphological novelty
1Institut de Biologie de l'ENS, Département de biologie, École normale supérieure, CNRS, INSERM, Université Paris Science and Lettres, Paris 75005, France.
Summary
Evolutionary rates for body size are stable, not slowing down as adaptive landscape theory predicts. Species sorting and sustained lineage evolution drive long-term trends, creating continuous novelty.
Area of Science:
- Evolutionary biology
- Paleontology
- Phylogenetics
Background:
- Understanding evolutionary rates is key to deciphering life's history.
- Adaptive landscape theory suggests evolutionary rates slow after reaching adaptive peaks, but evidence is debated.
Purpose of the Study:
- To develop and apply a novel phylogenetic model to assess body size evolution and rates.
- To test predictions of adaptive landscape theory against empirical data spanning 450 million years.
Main Methods:
- Developed a phylogenetic "diffused Brownian motion" model for nuanced rate variation.
- Analyzed body size evolution across 2,950 extinct and 792 extant species.
- Examined evolutionary rates over 450 million years of data.
Main Results:
- Evolutionary rates were found to be stable and not influenced by phenotypic disparity.
- Findings contradict adaptive landscape theory's predictions of rate slowdowns.
- Long-term body size increases result from sustained lineage evolution and clade-level sorting.
Conclusions:
- Evolutionary rates are more constant than previously assumed.
- Species actively shape their environments, driving continuous evolutionary novelty.
- Adaptive landscape theory may not fully explain macroevolutionary trends in body size.
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