AP Biology - Unit 7: Natural Selection

Flashcards covering key vocabulary and concepts from the lecture notes on Natural Selection, Hardy-Weinberg, Phylogeny/Evidence, and Speciation.

Natural Selection

Developed by Charles Darwin; established due to variation in the population and competition for resources; organisms with more favorable traits are more likely to survive and reproduce.

Examples of Natural Selection

Peppered moths and antibiotic resistance.

Artificial Selection

Organisms with certain traits are bred until the population has that trait; humans affect variation in the population.

Examples of Artificial Selection

Dog breeds, corn from Maize, and Wild Mustard -> Cauliflower, Broccoli, Cabbage, Kale & Kohlrabi.

Disruptive Selection

Selection for the two extreme phenotypes; selection against the intermediate phenotype.

Stabilizing Selection

Selection for the intermediate phenotype; selection against the two extreme phenotypes.

Directional Selection

Selection for an extreme phenotype; selection against the other phenotypes.

Biochemical Evidence of Evolution

Comparison of DNA or protein; comparison of the number of differences.

Homologous Structures

Similar structures due to common ancestry; Ex: Bat wing and Cat arm.

Ancestral/Derived Traits

Characteristics derived from ancestor or from descendants.

Biogeography

Distribution of species and ecosystems in geographic space & through geological time.

Sympatric Speciation

New species from a surviving ancestral species while both continue to inhabit the same geographic region.

Allopatric Speciation

Occurs when biological populations of the same species become isolated due to geographical changes.

Prezygotic Isolation

Before a zygote is created.

Behavioral Isolation

Two organisms have different mating rituals (dance, song, etc).

Temporal Isolation

Two organisms mate at different times (day, month, year, etc.).

Geographic Isolation

Two organisms are separated by a geographical barrier.

Habitat/Ecological Isolation

Two organisms mate in different ecological environments.

Mechanical Isolation

Two organisms are incompatible anatomically.

Gametic Isolation

Two gametes are unable to fuse.

Postzygotic Isolation

After a zygote is created.

Reduced Hybrid Viability

Hybrid is not healthy/viable.

Reduced Hybrid Fertility

Hybrid is not fertile.

Hybrid Breakdown

First-generation hybrid is ok, but second and more generations, the hybrid starts decreasing viability and fertility.