Multiple chromosomal inversions modulate continuous local adaptation along a steep thermal cline

Area of Science:

• Evolutionary genetics
• Population genetics
• Marine biology

Background:

• Chromosomal inversions are linked to ecotype divergence.
• Their role in continuous adaptive divergence of complex traits is unclear.

Purpose of the Study:

• Investigate how chromosomal inversions facilitate clinal adaptive divergence along environmental gradients.
• Understand the role of inversions in maintaining adaptation despite gene flow in marine fish.

Main Methods:

• Quantitative genetics
• Population genetics
• Transcriptomics
• Artificial selection experiments

Main Results:

• Three chromosomal inversions are associated with multiple adaptive traits and show strong divergent selection.
• These inversions display contrasting selection signatures across latitudes.
• Inversions appear to control distinct aspects of complex traits, enabling modular adaptation.

Conclusions:

• Chromosomal inversions are key drivers of clinal adaptive divergence in marine fish.
• Inversions facilitate adaptation to diverse environmental pressures by controlling complex traits modularly.
• This mechanism allows adaptation despite significant gene flow.