Chapter 7 Flashcards
(15 cards)
What did Darwin theorize?
Natural Selection
What is natural selection?
the theory that nature chooses individuals with traits that are most fit
Define biotic factor.
Living environmental factors (plants, other animals)
Define abiotic factor.
Nonliving environmental factors (soil, weather, access to water, ect)
What is artificial selection?
when humans select for specific traits (domestication, dog breeds)
What is convergent evolution?
when similar traits evolve from similar pressures in different/ unrelated species
What are the drivers of evolution? (3x)
Mutation, genetic drift, gene flow
What may cause genetic drift? (2x)
bottlenecks, founder effect
What may cause gene flow?
migration (in and out)
What are some ways ancestry can be visualized? (2x)
phylogenic trees, cladograms
What is speciation?
When two populations become reproductively isolated from each other and two new species evolve
What is allopatric speciation?
When speciation occurs via physical separation (a physical barrier)
What is sympatric speciation?
When speciation occurs via a reproductive barrier (unsexyness)
What are some prezygotic barriers? (5x)
temporal isolation (breeding times), habitat isolation, behavioral isolation (courtship/mating ritual), mechanical isolation (reproductive organs), gametic isolation (fertilization)
What are some postzygotic barriers? (3x)
hybrid inviability (death before maturity), hybrid sterility (cannot produce offspring with either parent species), hybrid breakdown (viable first gen, inviable second gen)
