LIFE 102 Lecture Notes - Sympatric Speciation, Allopatric Speciation, Reproductive Isolation
Document Summary
Speciation, the origin of new species, is at the focal point of evolutionary theory. Evolutionary theory must explain how new species originate and how populations evolve. Microevolution consists of adaptations that evolve within a population, confined to one gene pool. Macroevolution refers to evolutionary change above the species level. Concept 24. 1: the biological species concept emphasizes reproductive isolation. Species is a latin words meaning kind or appearance . Biologists compare morphology, physiology, biochemistry, and dna sequences when grouping organisms. The biological species concept states that a species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring; they do not breed successfully with other populations. Gene flow between populations holds the phenotype of a population together. Reproductive isolation is the existence of biological factors (barriers) that impede two species from producing viable, fertile offspring. Hybrids are the offspring of crosses between different species.
