What does Arabidopsis polymorphism look like genome-wide?
A. thaliana shows clear global population structure and isolation by distance; demography can mimic selection in standard tests.
Source
The pattern of polymorphism in Arabidopsis thaliana
What they did
Genotyped many markers across hierarchical and worldwide Arabidopsis accessions and analyzed structure, LD, and neutrality statistics.
What they found
Clear global structure and isolation by distance; selfing does not make it asexual lineages; polymorphism not unusually low; demography can invalidate naive selection tests.
The limits
What it doesn't show
Does not map every selected locus causing adaptation.
Key terms
- Population structure
- Systematic allele-frequency differences among groups.
- Isolation by distance
- Genetic similarity declining with geographic distance.
- Linkage disequilibrium (LD)
- Non-random association of alleles at different loci.
- Selfing
- Self-fertilization mating system.
Flashcards
Want these cards to stick?
Save the deck to NoteFren and study it with spaced repetition.
Quiz yourself
Global pattern
Common questions
Is A. thaliana asexual?
No—selfing ≠ clonal lineages.
Global pattern?
Clear population structure / IBD.
Polymorphism level?
Not unusually low vs flies/humans.
Selection tests caveat?
Demography can mimic selection.
More on Natural selection