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Genetic and morphological divergence among sympatric canids
R K Wayne1, B Van Valkenburgh, P W Kat
1Department of Biology, UCLA 90024-1606.
The Journal of Heredity
|November 1, 1989
Summary
Species divergence is influenced by evolutionary time, not just competition. South American foxes diverged rapidly, while African jackals showed little change over millions of years, challenging common evolutionary assumptions.
Area of Science:
- Evolutionary biology
- Comparative anatomy
- Molecular evolution
Background:
- Species character divergence is often linked to competition.
- The role of evolutionary time in divergence is frequently underestimated.
- Congeneric, sympatric canids provide a model for studying divergence.
Purpose of the Study:
- To investigate the relationship between evolutionary time and character divergence.
- To compare divergence patterns in South American foxes and African jackals.
- To assess the impact of time on morphological and genetic divergence.
Main Methods:
- Morphological analysis of body mass, dental, and cranial shape.
- Estimation of divergence time using mitochondrial DNA restriction site polymorphisms.
- Comparative analysis of two canid groups on different continents.
Main Results:
- African jackals exhibit low morphological divergence despite over 2 million years of evolution.
- South American foxes show significant morphological divergence within 250,000 years.
- Divergence patterns are inconsistent with recent common ancestry as the sole explanation for low divergence.
Conclusions:
- Evolutionary time significantly impacts the rate and extent of character divergence.
- Morphological stasis can occur over long evolutionary timescales in some lineages.
- Competition alone may not fully explain observed patterns of species divergence.