Unit 7 · 7.10 — Speciation [cite: 28, 44]
13 learning items · ~1.38% exam weight (unit share)
Everything to learn here
- Concept: True speciation occurs when two diverging populations become entirely reproductively isolated, preventing any gene flow and allowing totally independent evolutionary divergence [cite: 13, 45].
- Vocabulary: Allopatric Speciation — speciation that occurs strictly when populations are completely geographically separated by an impassable physical barrier [cite: 14, 45].
- Vocabulary: Sympatric Speciation — speciation occurring completely without geographic separation, often due to massive polyploidy errors or rapid behavioral shifts [cite: 14, 45].
- Vocabulary: Prezygotic Barriers — biological mechanisms (temporal, habitat, behavioral, mechanical) that successfully prevent mating or successful fertilization from ever occurring [cite: 45].
- Vocabulary: Postzygotic Barriers — biological mechanisms (reduced hybrid viability or absolute hybrid sterility) that completely prevent a hybrid zygote from successfully developing into a fertile, reproducing adult [cite: 45].
- Vocabulary: Vocabulary: Biological Species Concept — A definition of species as groups of organisms that can interbreed to produce fertile offspring.
- Vocabulary: Vocabulary: Punctuated Equilibrium — An evolutionary pattern where species undergo rapid change after long periods of little to no modification.
- Concept: Case studies like Hawaiian Drosophila illustrate how isolation and different ecological pressures lead to the formation of new species.
- Concept: Speciation is the process by which two populations become reproductively isolated, preventing the exchange of genetic material.
- Vocabulary: Vocabulary: Gradualism — The theory that evolution proceeds through the accumulation of small changes over very long periods.
- Vocabulary: Vocabulary: Adaptive Radiation — The rapid evolution of many species from a single ancestor when new environmental niches become available.
- Vocabulary: Vocabulary: Convergent Evolution — The process where unrelated species evolve similar traits independently due to adapting to similar environments.
- Concept: Reproductive isolation is maintained by pre-zygotic and post-zygotic barriers that prevent successful gene flow between different populations.
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