AP®︎ Biology: Topic 7.10 Flashcards
Master key terms and definitions for Topic 7.10 of AP Biology – Speciation to help you prep for quizzes and the AP exam.
Speciation
The formation of new species from existing populations through evolutionary divergence.
The formation of new species from existing populations through evolutionary divergence.
A condition in which populations can no longer interbreed and exchange genes.
A species is a group that can interbreed and produce viable, fertile offspring.
Random allele frequency changes can cause isolated populations, especially small ones, to diverge.
Related populations become increasingly different as they adapt to different environments.
Rapid diversification of one lineage into many species occupying different ecological niches.
Unrelated lineages independently evolve similar traits under similar selective pressures.
New species form after populations become geographically separated and reproductively isolated.
New species form without geographic separation, often through niche differences or mate choice.
Populations live in different habitats and rarely encounter each other to mate.
Populations breed at different times, preventing mating and gene exchange.
Different courtship signals or mating behaviors prevent populations from interbreeding.
Differences in reproductive structures prevent successful mating between populations.
Egg and sperm cannot fuse successfully, so fertilization does not occur.
A hybrid embryo forms but fails to develop properly or survive.
A hybrid survives but cannot produce functional gametes or fertile offspring.
First-generation hybrids are viable, but later generations have reduced fitness or fertility.
Selection favors both extreme phenotypes over intermediate forms within a population.
Fruit flies on Hawaiian islands illustrate divergent evolution and allopatric speciation across islands.
A host shift from hawthorn to apple led to reduced gene flow without geographic separation.
Lizards with different displays, dewlap colors, and habitats show behavioral reproductive isolation.
Rapid evolutionary change after long stasis contrasts with slow, continuous change over time.
Before fertilization barriers prevent mating, while after fertilization barriers reduce hybrid viability or fertility.
