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Using ghost lineages to identify diversification events in the fossil record
1Department of Palaeontology, The Natural History Museum, London SW7 5BD, UK. lionel.cavin@ville-ge.ch
Biology Letters
|February 8, 2007
Summary
This study introduces a new method to distinguish genuine species diversification from fossil record bias. A drop in average ghost lineage duration indicates true evolutionary radiation, as seen in Cretaceous ray-finned fish.
Area of Science:
- Paleontology
- Evolutionary Biology
- Ichthyology
Background:
- Fossil diversity records may be skewed by preservation biases, complicating interpretations of true species diversification.
- Differentiating between genuine evolutionary radiations and artifacts of the fossil record is crucial for understanding macroevolutionary patterns.
Purpose of the Study:
- To develop and test a novel method for distinguishing true diversification events from preservational biases in the fossil record.
- To apply this method to assess the nature of diversity changes in Cretaceous ray-finned fishes.
Main Methods:
- Calculated the average ghost lineage duration across successive time intervals.
- Hypothesized that genuine radiations cause a drop in average ghost lineage duration, while preservation bias does not.
- Applied the method to Aptian-Maastrichtian ray-finned fish fossil data.
Main Results:
- The developed method successfully differentiates between genuine diversification and preservational bias.
- A significant drop in average ghost lineage duration was observed during the Cenomanian.
- This indicates a genuine biological radiation event in ray-finned fishes during the Cenomanian.
Conclusions:
- The ghost lineage duration method provides a robust tool for interpreting fossil diversity data.
- Cretaceous ray-finned fish diversity shows evidence of a true evolutionary radiation event in the Cenomanian.
- This finding enhances our understanding of macroevolutionary dynamics in marine ecosystems.
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