W9L3 - Population Genetics Flashcards
(17 cards)
What is population genetics
study of variation within populations and the evolutionary forces which shape it
What must the frequencies of all the alleles of a gene add up to
one or 100%
What does it mean if a population is in Hardy-Weinberg equilibrium
it is not evolving and allele frequencies will stay the same across generations
Explain the components of this equation and what type of frequency it measures
Measures allele frequency and p -> frequency of dominant allele, q = frequency of recessive allele
Explain the components of this equation and what type of frequency it measures
genotype frequency p^2 = frequency of homozygous dominant genotype, 2pq = frequency of heterozygous genotype (Gg), q^2 = frequency of homozygous recessive genotype (gg)
When the Hardy-Weinberg equilibrium is in equilibrium what are the 2 things that are true?
- Allele frequency will not change from one generation to the next
- the actual genotype frequencies observed in the population will match the predicted genotypes based on the Hardy-Weinberg model.
What does it mean if the gene in the population is not in Hardy-Weinberg equilibrium?
An evolutionary force is acting up on it
What is evolution?
change in the frequencies of alleles in a population over successive generations
What is genetic drift
changes in allele frequency due to chance events such as bottleneck/founder effect
What is the bottleneck effect
population gets drastically reduced (E.g natural disaster, disease etc > smalle group survives = decrease in genetic variations
What is the founder effect
small group leaves a population = start a new one somewhere else = new population gene is based on the founders not the original population
What is non-random mating
individuals choose mates on the basis of phenotype = sexual selection, when humans intervene = selective breeding
What is natural selection
Individuals that possess advantageous traits = increase likely to reproduce = increase prevalence hence adapts to its environment
What is migration
movement of individuals from one population to another
What is immigration
movement of individuals INTO a population
What is emigration
movement of individuals OUT of a population
What is gene flow
movement of genes/alleles from one population through the migration of individual and subsequent mating with members of the recipient population
