Hardy-Weinberg Equilibrium Flashcards
Define Biological Evolution.
The process through which the characteristics of organisms change over generations, driven by evolutionary mechanisms: Genetic drift, Migration, Mutation, Selection, and Non-random mating
What is the difference between Microevolution and Macroevolution?
Microevolution is small-scale changes within a pop. (mostly changes in allele frequencies over a few gens.) Macroevolution is a larger evolutionary change that leads to new species or groups
What is Microevolution?
Microevolution is the process of change.
What is Macroevolution
Macroevolution is the pattern of change.
What is an EX. of Macroevolution?
The evolution of mammals from reptilian ancestors
What is an EX. of Microevolution?
The change in color in a moth pop. due to pollution
What five conditions must be met for the proportions of alleles not to change? (Hardy-Weinberg Equilibrium)
The pop. is large
No migration in or out
No Mutations
Mating is random
All genotypes are just as fit
What are the five evolutionary mechanisms?
Genetic drift
Migration
Mutation
Selection
Non-random mating
Define Genetic drift
The random changes in allele frequencies
the allele can drift up and down from one gen to the next
Define Migration (Gene flow)
Movement of individuals between pop. leads to changes in allele frequencies
Define Mutation (rare)
Changes in the DNA sequence can introduce new genetic variation into a pop. It can be beneficial, neutral, or harmful
Define Selection
The process by which some traits become more common in a pop. because they have an advantage
Define Non-random mating
Mating that is based on specific traits leading to changes in genotype frequencies
The survival rate of a genotype (or phenotype) relative to the maximum survival or both reproductive rates of other genotypes in the population
It is a number between 0 and 1.
Relative Fitness
In population genetics what can cause fixation?
Genetic drift or selection
Genetic drift: random changes in allele frequencies can lead to fixation in small pop.
Selection: helpful alleles can become fixed if they have a survival benefit
The changes in a gene pool from a situation where there exists at least two variants of a particular gene (allele) in a given population to a situation where only one of the alleles remains. The gene has become “fixed.” What is this called?
Fixation
Summarize the effect of natural selection on the evolution of populations. Use the term “fitness” in your explanation.
Natural selection impacts evolution by selecting genotypes/phenotypes that have high fitness, leading to allele changes over time.
What is assortative mating?
Individuals choosing partners that have similar (positive assortative mating) or dissimilar (negative assortative mating) to themselves in certain traits
What is the definition of Hardy-Weinberg equilibrium?
Fundamental principles of pop. genetics that describes a state where allele and genotype frequencies in a pop. remain constant from gen. to gen. if conditions are met
p^2 + 2pq + q^2 = 1
where
p: The frequency of the dominant allele in the population
q: The frequency of the recessive allele in the population
p^2 = frequency of genotype Homozygous dominant (RR)
q^2 = frequency of genotype Homozygous recessive (rr)
2pq = frequency of genotype Heterozygous (Rr)
The mathematical representation of Hardy-Weinberg equilibrium