Hardy-Weinberg
What does the Hardy-Weinberg principle predict?
Allele and genotype frequencies will remain constant in a population if no evolutionary forces act on it.
Which type of selection favors the average phenotype?
Stabilizing selection
What is genetic drift?
A change in allele frequencies due to random chance
What is speciation?
The formation of new species
What is anagenesis?
Evolution within a single lineage without branching
What are the five conditions required for Hardy-Weinberg equilibrium?
Large population, random mating, no mutations, no gene flow, no natural selection
Which type of selection favors one extreme phenotype?
Directional selection
What is the founder effect?
Genetic drift that occurs when a small group colonizes a new area
What is allopatric speciation?
Speciation due to geographic isolation
What is cladogenesis?
Evolution that results in the splitting of a lineage into two or more species
Which Hardy-Weinberg condition would be the most difficult to maintain when studying a large population of worms in a lab?
No mutations
Which type of selection favors both extreme phenotypes over the average?
Disruptive selection
What is the bottleneck effect?
A sudden population reduction that changes allele frequencies
Name two prezygotic isolation barriers.
Temporal, behavioral, mechanical, habitat
What helps preserve genetic diversity in a population?
Heterozygote advantage, gene flow, mutations, frequency-dependent selection
Why is Hardy-Weinberg considered a "null model"?
Why is Hardy-Weinberg considered a "null model"?
Give an example of directional selection in nature.
Ex: Beak size in Darwin’s finches during drought
What is assortative mating?
Mating between individuals with similar phenotypes
What is hybrid sterility?
A postzygotic barrier where offspring cannot reproduce
What does fecundity mean in an evolutionary context?
The reproductive output of an individual
What is Hardy-Weinberg's Equation?
P2+2PQ+Q2=1
What type of selection may lead to speciation by splitting a population into two phenotypic groups?
Disruptive selection
Why does non-random mating violate Hardy-Weinberg?
It leads to sexual selection- a type of evolution
What is the difference between prezygotic and postzygotic barriers?
Prezygotic prevents mating or fertilization; postzygotic affects offspring viability or fertility
How can species be identified? (2 ways)
Biological, morphological, ecological, phylogenetic species concepts