Limited Evidence for Parallel Evolution Among Desert-Adapted Peromyscus Deer Mice

Area of Science:

• Genomics
• Evolutionary Biology
• Conservation Genetics

Background:

• Climate change and desertification necessitate understanding heat and dehydration tolerance genes.
• Comparing desert-adapted species can reveal shared evolutionary adaptations.
• Identifying genetic signatures of selection aids biodiversity conservation.

Purpose of the Study:

• To investigate parallel evolution in desert adaptation by comparing genomic signatures of selection.
• To identify candidate genes associated with heat and dehydration tolerance in the canyon mouse (Peromyscus crinitus).
• To explore divergent molecular mechanisms of adaptation among deer mouse species.

Main Methods:

• Generated a chromosome-level genome assembly for Peromyscus crinitus.
• Analyzed population-level genomic resequencing data from Peromyscus eremicus and Peromyscus maniculatus.
• Compared signatures of selective sweeps across species to identify shared and unique adaptation loci.

Main Results:

• Few shared candidate loci for desert adaptation were identified across the studied species.
• No strong support for a shared pattern of parallel evolution in arid adaptation was found.
• Identified candidate genes in P. crinitus related to osmoregulation and metabolic tuning under selective pressure.

Conclusions:

• Desert adaptation in deer mice likely involves divergent molecular mechanisms rather than parallel evolution.
• Species-specific historical demography may influence the capacity for arid adaptation.
• Candidate genes involved in osmoregulation and metabolism offer insights into P. crinitus's adaptation to hot, dry environments.