Theme 4B Flashcards
(11 cards)
What is a population?
An interbreeding group of individuals that belong to the same species and live within a restricted geographical area
What is the shift from mendelian genetics to population genetics?
Shift from individual to population level thinking. The frequency of an allele in a population is often not the same as the ratio in a single cross
When will evolution by natural selection not occur?
No variation, variation is not heritable, variation is heritable but has no fitness consequence
What is the null hypothesis for evolution?
There will be no change in allele frequencies over time
What is the first condition of Hardy Weinburg?
A single locus with two alleles does not change state between generations (no evolution, no mutation). No new alleles arise in the population
What is the second condition of Hardy Weinburg?
Alleles are not added to the population or taken away (no gene flow from other populations such as immigration and emmigration)
What is the third condition of Hardy Weinburg?
The population is very big (infinite in theory). This assumption eliminates the effect of random processes that could change allele frequencies (like genetic drift).
What is the fourth condition of Hardy Weinburg?
Natural selection does not affect the alleles considered. Regardless of genotype at locus, all diploid individuals have the same fitness. Probability of surviving to breed, mate, fertilizing is the same for all individuals. Genotypes do not differ in fitness
What is the fifth condition of Hardy Weinburg?
Random mating; regardless of their genotype at the locus, all diploid individuals have the same chance of mating (equally likely for all)
When all these conditions of hardy Weinburg are present, what happens to allele frequencies?
The allele frequencies will stay constant between generations
What does Hardy Weinburg tell us in general?
In it a null hypothesis, so it tells us when evolution is not happening
