Chromosomal inversions often underlie local adaptation and reproductive isolation and are widely believed to evolve via natural selection.Yet, in spite of a long history of study, the specific role chromosomal inversions play during adaptation remains unclear.
A key model authored by Kirkpatrick & Barton posits that inversions can be favored by selection if they create tightly-linked “cassettes” of locally-adapted alleles that act as single alleles of large effect and are shielded from maladaptive gene flow.
The core prediction of this model is that maladaptive gene flow generates a fitness differential between inverted and non-inverted haplotypes, which results in the inverted haplotype evolving to high frequency.
As part of my NSF-funded research at Duke University, I am working on an experimental test of this idea. Our two aims are:
- Create several novel chromosomal inversions using modern transgenic approaches.
- Perform an experimental test of the role of maladaptive gene flow in driving the adaptive evolution of these inversions.