BIO Exam 3 Review

What is Population Evolution?

Selection acts on individuals carrying alleles for certain traits, Evolution occurs in populations

What is Microevolution?

change in allele frequency in a population over generations

What are the 4 sources of genetic variation?

1) Mutations

2) Sexual Reproduction

3) Gene Flow

4) Genetic Drift

What is a Gene Pool?

allele frequencies in a population

Why can the # of alleles per gene in an individual be different from the # of alleles per gene in a population?

Individuals inherit only 1 allele from each parent, a population’s gene pool includes all variants

What is genetic drift?

allele frequency changes w/o regard to if traits provide a reproductive advantage

What is the founder effect?

group of individuals immigrates to a new area and establishes a new population, change in allele frequency when a new population is established

What does the founder effect do?

increases genetic drift

What is the bottleneck effect?

reduction in the diversity of alleles in a population

What are the types of Natural Selection?

• Directional: changes the average value of a trait

• Disruptive: increases variation in a trait

• Stabilizing: reduces variation in a trait

What is Directional selection?

average phenotype of a population changes in one direction, a more extreme phenotype is favored

What is Selection pressure?

aspect of the environment that reduces survival and reproductive of a phenotype

What is Disruptive selection?

overall amount of genetic variation among individuals in the population is increased, eliminates phenotypes near the average value

What is Stabilizing selection?

genetic variation in the population is reduced, but no change in average value of a trait

What is the Hardy-Weinberg Principle?

allele and genotype frequencies in a large population will remain constant from generation to generation

What are 5 conditions that lead to changes in allele frequency in a population?

1) Mutation

2) Gene Flow

3) Genetic Drift

4) Non-random mating

5) Natural Selection

Difference between random & adaptive evolution?

• random evolution has genetic drift and mutations that change gene frequencies

• adaptive evolution is a directional change driven by natural selection

What does the branching pattern on a phylogenetic tree indicate about evolutionary relationships?

order of divergence and common ancestry

What is a Taxon?

named unit at any levels of hierarchy (ex: family)

What is Phylogeny?

evolutionary history of a group of organisms with their lineage and relationships

What is the Sister Taxa?

2 closest relatives in a phylogenetic tree sharing a common ancestor

What are Shared Ancestral characters?

characters that originate in the ancestor

What are Shared Derived characters?

characters different from ancestor and unique to the clade

What is a Clade?

complete group of descendants from a single ancestor

What are homologies?

character inherited from a recent common ancestor

What is homoplasy?

character that does not share a recent common ancestor

What are characteristics shared by Archae & Bacteria, but not Eukarya?

Both have a circular chromosome, RNA polymerase

What are characteristics shared by Archaea & Eukarya, but not Bacteria?

Both have RNA polymerase,

What are the ancestral characteristics that unite the Archaeplastida?

What are the shared derived traits that unite the plant kingdom?

Cuticle and pores

What is a Gene pool?

What is a locus?

What is a gene?

What is an Allele?

What is stabilizing selection?

What is disruptive selection?

What is directional selection?

What is gene flow?

individuals from a distinct population bring new alleles into the local population

What is sexual dimorphism?

What is parsimony?

What is sister taxa?

What is an out group?

What is a shared ancestral character?

What is a shared derived character?

What is Cynobacteria?

What is endosymbiosis?

What is Archaea?

What is an ancestral character?

What is a shared derived trait?

What is the definition of Biotic?

What is the definition of Abiotic?

What is the definition of niche?

What is Trophic level?

What is the definition of a population?

What is the definition of a ecosystem?

What is clumped dispersion?

What is random dispersion?

What is uniform dispersion?

What is a Quadrat?

What is a Transect?

What is a mark recapture?

What is the definition of carrying capacity?

What is the definition of birth rate?

What is the definition of death rate?

What is dispersion?

How organisms are distributed spatially

What are the 3 methods of estimating population density?

What is exponential growth?

What is logistic growth?

Density dependent vs. Density independent?