BIO 1306 Lecture Notes - Lecture 4: Species Problem, Allopatric Speciation, Species

38 views3 pages
2 Feb 2017

Document Summary

In the gal pagos islands darwin discovered plants and animals found nowhere else on earth. 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 changes in allele frequency in a population over time. Macroevolution refers to broad patterns of evolutionary change above the species level. Concept 24. 1: the biological species concept emphasizes reproductive isolation. Species is a latin word 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 members of other populations. Gene flow between populations holds a species together genetically. Reproductive isolation is the existence of biological factors (barriers) that impede two species from producing viable, fertile offspring.