Genetics of Adaptation Flashcards
What are the three steps to demonstrate adaptation by natural selection?
Link trait values with fitness values by comparing variations.
Identify the genetic basis of the trait, including genes and alleles.
Show how ecological context causes evolutionary changes in the trait.
Why is it important to know the genetic basis of a trait when studying adaptation?
It helps identify the specific genes and alleles contributing to the phenotype, enabling better understanding of the evolutionary process.
How do realistic tests help demonstrate mechanisms of selection?
They link specific ecological contexts to how selective forces influence trait evolution.
What are the two main sources of adaptive alleles?
New mutations arising in populations.
Standing genetic variation, where existing alleles become advantageous in new contexts.
Which allows faster adaptation: new mutations or standing variation?
Standing variation allows faster adaptation because alleles already exist in the population and can quickly become advantageous under selective pressure.
Under what conditions do novel mutations contribute to adaptation?
They contribute when they provide a fitness advantage, but their impact depends on environmental context and whether they occur at the right time.
How does environmental context affect mutation fitness?
Mutations are neutral in non-selective environments but advantageous when selective pressures (e.g., high salt) provide fitness benefits.
How does parallel evolution differ from convergent evolution?
Parallel evolution involves closely related species developing similar traits independently, while convergent evolution involves unrelated species evolving similar traits due to similar environments.
What are QTL and how are they studied?
QTL are genome regions influencing quantitative traits, studied through methods like genome-wide association studies (GWAS).
What are two key pathways for adaptation?
New mutations provide fresh genetic material.
Standing variation repurposes existing alleles under new selective pressures
