Evolutionary genomics I (DONE) Flashcards
What is the focus of evolutionary genomics?
Understanding the genetic basis of phenotypic variation & how genetic variation shapes adaptation, speculation & evolution
What are the main processes shaping genomic variation?
Selection, gene flow & recombination
What are genome-wide association studies (GWAS)?
GWAS identify genetic variants associated w phenotypic traits across the genome
How do Manhattan plots help in GWAS?
They visualise the strength of association between genetic variants & phenotypic traits
What is the genetic basis of phenotypic variation in Darwin’s finches?
Variants influencing blunt vs pointed beaks, potentially linked to ancient alleles
What does “standing variation” mean?
Pre-existing genetic variation in a population that selection can act upon
What is a selective sweep?
A process where beneficial mutation rapidly increases in freq –> reducing genetic diversity near the locus
How do hard & soft selective sweeps differ?
Hard sweeps = involve new mutations
Soft sweeps = act on existing variation
What genomic signature indicated a selective sweep?
- Reduced genetic diversity
- Inc linkage disequilibrium
- Higher differentiation from other pops
What study demonstrated habitat-driven genetic selection?
Deer mice (Peromyscus maniculatus) showing coat colour adaptation to their environment
What is genetic drift?
Random changes in allele frees, significant in small pops
What is gene flow?
Exchange of genetic material between pops, introducing variation
What is adaptive introgression?
Transfer of beneficial alleles between species through hybridisation
Give an example of adaptive introgression?
Snowshoe hares acquiring winter coat colour adaptation thru gene flow
What role does recombination play in genomic variation?
It reshuffles genetic material, breaking linkage disequilibrium & shaping genetic diversity
