What does natural selection act upon?
the individual
The results of natural selection, which is evolution, are measured at the population level.
What is the key question addressed in the lecture regarding population genetics?
How do we know when the genes of a population have changed?
This question focuses on determining if evolution has taken place.
In a monohybrid cross, what is the F1 generation composed of?
heterozygous individuals
This generation results from mating two purebred individuals with a trait caused by 2 alleles.
What are the genotypes and their probabilities represented by in a population with alleles R and r?
R2 + 2Rr + r2 = 1.0
This equation represents the frequency of different genotypes within the generation created by hybrid parents.
What do p and q represent in population genetics?
- p: frequency of one allele
- q: frequency of the second allele
The sum of p and q must equal 1.0.
What is the Hardy-Weinberg Equilibrium equation?
p2 + 2pq + q2 = 1.0
This equation expresses the combined genotypic frequencies in a population.
If there are 4 alleles (p, q, w, z) at the same locus, what is the equation for their frequencies?
(p + q + w + z) x (p + q + w + z) = 1.0
This represents the combined genotypic frequency for multiple alleles.
What does the Hardy-Weinberg Principle state about allele frequencies?
- p is always the same generation after generation
- q is always the same generation after generation
This principle challenges earlier beliefs about dominant and recessive traits.
What are the assumptions of the Hardy-Weinberg model?
- Random mating
- No mutation
- No migration
- Infinite population size
- No natural selection
If any assumption is violated, H-W does not apply.
What does the Hardy-Weinberg equilibrium hypothesis act as?
a null hypothesis
It is used to determine if genetic changes are taking place at a particular locus within a population.
What happens if the change in data from one generation to the next is greater than what randomness would allow for?
the null hypothesis is rejected
This indicates that the population has evolved.
What is the typical approach researchers take when they detect a change in a population?
They hypothesize what is causing the change and develop an experiment to test it
Researchers often assume that a violation of Hardy-Weinberg assumptions is causing the change.
