Triangulating the genetic basis of adaptation to multifarious selection

Area of Science:

• Ecological genomics
• Evolutionary biology
• Population genetics

Background:

• Understanding adaptation in natural populations is key to ecological genomics.
• Identifying genetic drivers of adaptation is challenging due to complex selective pressures and polygenic traits.
• The freshwater microcrustacean Daphnia is a model organism for studying adaptation.

Purpose of the Study:

• To disentangle the genomic signature of multidimensional selection in Daphnia populations.
• To identify candidate genomic regions associated with adaptation to predation, parasitism, and anthropogenic land use changes.
• To provide a template for future ecological genomics research combining multiple approaches.

Main Methods:

• Utilizing spatially structured Daphnia populations across a geographic mosaic of environmental stressors.
• Analyzing historical genotypes preserved in lake-bottom sediments.
• Conducting selection experiments to observe adaptive responses.
• Combining genomic investigation with ecological and experimental approaches.

Main Results:

• Identification of specific genomic regions associated with adaptation to distinct environmental pressures.
• Demonstration of Daphnia's capacity for repeated adaptive evolution in response to isolated selective pressures.
• Successful disentanglement of multidimensional selection's genomic footprint.

Conclusions:

• The study successfully identified genomic regions linked to adaptation in Daphnia populations facing multiple stressors.
• This research provides a robust framework for future ecological genomics studies using model organisms.
• The findings highlight the power of integrating ecological, historical, and experimental data for understanding adaptation.