L27 Ecological Genetics Flashcards
Ecological Genetics
see onenote
Study of evolutionary forces in an ecological context
Genetics of ecologically important traits
Concerned with evolution that can be fast e.g. related to human activities
Biotic vs Abiotic
Biotic
- Predator-prey relationship
- Disease
- Competition
Abiotic
- Nutrition
- Temperature
- Water
Biotic and abiotic factors can interact, not independent of each other BUT we treat them as independent
Ecological genetic focusses on genetic diversity in an ecological genetics
see onenote
- molecular genetic diversity
- trait polymorphisms
- quantitative genetic diversity
An adaptive molecular marker
see onenote
- allozyme variation in butterflies
- phosphoglucose isomerase (PGI)
PGI
see onenote
- heterozygotes for PGI are more active at cooler morning temperatures
- early flight provides reproductive fitness advantage
- functional studies suggest why PGI heterozygotes fly better in the cold
- in vitro measure of catalytic efficiency at low temperatures
- adaptive, natural selection infuences allelic frequencies of polymorphic gene
- PGI is polymorphic
- maintained by balancing selection
Many other examples of polymorphisms under selection
- allozymes
- chromosomal rearrangements
- indels
- SNPs
- evidence difficult to collect, led to attempts to scan for multiple polymorphisms
Polymorphism scans
see onenote
- time or space
- across environmental gradients
- gradients replicated
- use Fst to identify outliers
Habitat-mediated selection
see onenote
Swiss alps vs French alps
2 outliers that were relevant
- Anything above the line was an outlier, potential signature of selection
- Same outliers between Swiss alps and French alps at same elevation and Fst BUT a lot of the other dots were not the same - adaption at different loci? Is the outlier actually an outlier?
Polymorphism scans depend on…
see onenote
Genes that repeatedly pop out
Genes that repeatedly pop out
- Genes are linked in the network
- Level of repeatability not at the gene level but at the network level, all connected in the some way (a little bit of this gene and that gene?)
- Replay the tape and end up with a slightly different answer BUT you still end up in the same network
- In ecological genetics, not worth it to study a single gene but may be worth it to study a single gene in a network
How often can variation in genes be associated with ecologically relevant traits?
- Sometimes
- Maybe more often in a network
- More so in a group of relatable genes
- Don’t forget functional analyses
