Genetics Flashcards
What is the definition of an evolutionary force?
Any factor that brings about changes in allele frequencies over time in a population and is thus capable of causing evolutionary change
What are the 4 evolutionary forces?
natural selection
mutation
random genetic drift
gene flow
What is a population?
A groups of organisms of the same species living in the same georgraphical area at the same time who have the capacity of interbreeding
What is Hardy-Weinberg principle?
The principle states that in the absence of evolutionary forces allele frequencies in a population will remain constant from one generation to the next
What is the Hardy-Weinberg equation?
p^2 + 2pq + q^2 = 1
What are the differences between migration and gene flow?
migration is more or less a permanent move of individuals which doesn’t always involve interbreeding between immigrant and host
gene flow always involves interbreeding but not involve a permanent migration
What is random genetic drift?
A mechanism for evolutionary change resulting from random fluctuations in allele frequencies from one generation to the next
What is founder effect?
Genetic differences between a newly founded population and its parent population due to the small size of the founding group
What is population bottleneck?
A bottle neck occurs when many members of a population die and only a few are left to reproduce. The new population has a restricted gene pool with different allele frequencies
What is a key factor that determines the rate of evolution due to RGD?
Population size - inverse relationship
What is a genetic polymorphism?
The occurrence of two or more commonly occurring alleles at a locus in a population, frequency of the most common allele less than 0.99
What is an example of a polymorphism?
Sickle cell in Africa
When is a locus monomorphic?
When the most common allele has a frequency of greater than 0.99
What is an example of a monomorphism?
ABO in South American natives - all group O
What is a gene pool?
The sum of all the genetic material in a population
How can a population that was monomorphic become polymorphic?
Mutation
Gene Flow
Natural Selection
Genetic Drift
Sexual selection
polyploidy
Is gene flow increasing or decreasing?
gene flow can enhance RGD by introducing new genetic material and maintaining diversity,
RGD can affect patterns of gene flow through local adaptation and ecological barriers.
How does gene flow interact with RGD?
gene flow can enhance RGD by introducing new genetic material and maintaining diversity, while RGD can affect patterns of gene flow through local adaptation and ecological barriers.
What are the assumptions of Hardy-Weinberg?
the allele and genotype frequencies in a population will remain constant from generation to generation
From an evolutionary perspective, what does a change in allele frequencies mean?
a change in allele frequencies signifies that evolutionary processes are occurring within a population
What are the consequences of inbreeding?
inbreeding can have profound negative effects on individuals and populations, leading to reduced fitness, increased health issues, and greater extinction risk.
What is the coefficient of inbreeding?
the coefficient of inbreeding quantifies the degree of inbreeding in an individual or population, providing important insights into genetic health, fitness, and evolutionary potential.
What are similarities between simple and complex traits?
Genetic Basis
Phenotypic Variation
Environmental Influence
Heritability
Selection Pressure
Differences between simple and complex traits
Simple Traits: controlled by a single gene or a few genes
- inheritance patterns, such as dominant-recessive relationships.
- typically discrete, meaning individuals either express the trait or they do not
Complex traits: influenced by multiple genes, often located at different loci.
- the effects of multiple genes contribute to the phenotype
- significantly affected by environmental factors.
What does heritability capture?
the genetic contribution to phenotypic variation in a trait
What are concordance rates used for?
for assessing the genetic and environmental contributions to traits and diseases.
How is heritability measured?
parent-offspring regression, sibling comparisons, twin studies, and variance partitioning.
The distinction between narrow and broad sense heritability
What are some limitations of heritability?
population specificity
environmental influences
potential for misinterpretation
the complexity of genetic interactions.
