Related Experiment Videos
Rapid allopatric speciation in logperch darters (Percidae: Percina)
Thomas J Near1, Michael F Benard
1Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996-1610, USA. tnear@utk.edu
Evolution; International Journal of Organic Evolution
|February 9, 2005
Summary
Diversification rates in logperches, a freshwater fish clade, are unexpectedly high, challenging the idea that rapid speciation only occurs in sympatric environments. This study shows allopatric speciation can also be very fast.
Area of Science:
- Evolutionary Biology
- Speciation Research
- Ichthyology
Background:
- Theory suggests sympatric speciation leads to high diversification rates.
- Allopatric speciation's diversification rate is less understood.
- Previous studies linked higher speciation rates in freshwater fish to sympatric modes.
Purpose of the Study:
- To test if diversification rate can infer the geographic mode of speciation.
- To investigate diversification rates and speciation patterns in logperches, a darter clade.
Main Methods:
- Generated a phylogeny using mitochondrial DNA gene sequences for 10 logperch species.
- Estimated divergence times using a fossil-calibrated molecular clock.
- Calculated diversification rates using multiple methods and examined geographic speciation patterns.
Main Results:
- Logperch speciation is recent (4.20 to 0.42 million years ago), primarily in the Pleistocene.
- Observed high diversification rates, some exceeding those of known adaptive radiations.
- Diversification in logperches appears allopatric despite high rates.
Conclusions:
- Diversification rate alone cannot determine the geographic mode of speciation.
- Allopatric speciation can occur rapidly, as demonstrated by logperches.
- High diversification rates are not exclusive to sympatric speciation.