Biology - Unit 7: Evolution

AP/IB Biology Unit 7 flashcards

Darwin's Theory of Evolution

Explains evolution via natural selection and genetic variation.

Natural Selection

Survival of better-adapted individuals in an environment.

Microevolution

Small evolutionary changes within a species over time.

Macroevolution

Large-scale evolutionary changes leading to new species.

Radioactive Carbon Dating

Dating method using carbon-14 decay in organic materials.

Convergent Evolution

Different species develop similar traits due to environment.

Divergent Evolution

Related species evolve different traits over time.

Homologous Organs

Same structure, different function across species.

Analogous Organs

Different structure, same function across species.

Punctuated Equilibrium

Rapid evolution followed by long periods of stability.

Gradualism

Slow, continuous evolution over long time periods.

Population Genetics

Study of allele frequency changes within populations.

Gene Polymorphisms

Variations in DNA sequences within a population.

Natural Selection Factors

Natural selection, genetic drift, mutation, gene flow, mating.

Mutation

Random DNA changes creating new alleles in populations.

Migration

Movement of alleles between populations affecting diversity.

Genetic Drift

Random changes in allele frequencies in small populations.

Founder Effect

New population established by a small group.

Bottleneck Effect

Population reduction leading to decreased genetic diversity.

Nonrandom Mating

Mating patterns that affect allele frequencies in populations.

Directional Selection

Favors extreme traits, shifting population mean in one direction.

Stabilizing Selection

Favors average traits, reducing variation in a population.

Disruptive Selection

Favors extreme traits, potentially leading to speciation.

Fitness

Ability to survive and reproduce in an environment.

Species

Group of organisms capable of interbreeding and producing offspring.

Allopatric Speciation

Speciation due to geographic isolation of populations.

Sympatric Speciation

Speciation occurring without geographic isolation.

Niche

Role of an organism in its environment.

Clone

Genetically identical organism produced asexually.

Ecotypes

Genetically distinct populations adapted to specific environments.

Prezygotic Isolation Mechanisms

Barriers preventing fertilization between different species.

Postzygotic Isolation

Barriers occurring after fertilization affecting hybrid viability.

Adaptive Radiation

Rapid evolution of many species from a common ancestor.

Darwin's Finches

Example of adaptive radiation and natural selection.

Hybridization

Interbreeding between different species producing hybrids.

Rapid Evolution

Quick evolutionary changes due to strong selective pressures.