Evolution (Topic 4) - Key Terms

Vocabulary flashcards covering key terms from evolution, genetic drift, speciation, polyploidy, and reproduction.

Geographic isolation

A physical barrier like an ocean/river that divides populations and blocks gene flow.

Non-disjunction

Failure of chromosome pairs to separate properly during meiosis, creating abnormal chromosome numbers.

Prezygotic isolation

Barriers that prevent mating or fertilization between populations (e.g., timing, behavior, habitat).

Postzygotic isolation

Barriers after fertilization that reduce viability or fertility of hybrids.

Genetic drift

Random changes in allele frequencies across generations due to chance rather than selection.

Bottleneck effect

A big reduction in population size that lowers genetic variation and shifts allele frequencies.

Founder effect

A bottleneck where a new population is started by a small sample of individuals, reducing genetic diversity.

Gene flow

Movement of alleles between populations

Speciation

The process by which one lineage splits into two or more distinct species.

Sexual reproduction

Reproduction involving two parents, producing offspring with greater genetic variation than asexual reproduction.

Asexual reproduction

Reproduction without a mate; offspring are genetically similar.

Antibiotic resistance

In bacteria, where mutations confer survival in the presence of antibiotics.