AP®︎ Biology: Topic 8.7 Flashcards

A heritable variation favored by selection because it increases fitness in a specific environment.

Mutations arise by chance, but selection nonrandomly increases beneficial variants and removes harmful ones.

The heterozygous genotype has higher fitness than either homozygous genotype in a given environment.

A nonnative organism that spreads in a new ecosystem and disrupts native populations or ecosystem processes.

Introduced species often expand rapidly because predators, parasites, or competitors are absent in the new habitat.

An introduced vine in the southeastern United States that rapidly overgrows and smothers native vegetation.

An invasive freshwater mollusk that clogs infrastructure and removes plankton from aquatic food webs.

Toxin concentration increases at higher trophic levels as predators consume contaminated prey.

Excess nutrients cause algal blooms whose decomposition depletes oxygen in aquatic ecosystems.

Human movement can spread pathogens into new regions where native species lack resistance.

An introduced fungal disease spread by bark beetles that killed large numbers of elm trees.

A water mold disease introduced to susceptible crops, causing widespread potato failure.

Long-term shifts in temperature and precipitation that alter habitats, species ranges, and ecosystem processes.

Large-scale tree removal that destroys habitat, fragments forests, and changes community structure.

Conversion of natural land into cities, causing habitat fragmentation, pollution, and heat island effects.

Growing one crop over large areas, reducing biodiversity and simplifying ecosystem structure.

Periodic warming of the tropical Pacific that shifts global weather, rainfall, and ecosystem conditions.

Tectonic plate movement that changes landmass positions, isolating or connecting populations over time.

A mass extinction event caused by asteroid impact that drastically reshaped global ecosystems.