BIOL 1202 Lecture : BIO 1202 Notes
Document Summary
Homologous and analogous structures: homologous other because of common ancestry. Structures or other attributes in different species that resemble each: analogous. Structures that are similar in function but not in structure and developmental and evolutionary origin. Homologous structures: vertebrate embryos: all vertebrates share similar developmental genes, differences arise by some genes being switched on or off at varying times during development. Convergent evolution: similarity between 2 organisms structures or molecules due to independent evolution along similar lines rather than descent from a common ancestor. Fossil record: show change in organisms through time, change in types of organisms. Many species have become extinct: not only provides evidence of small-scale changes but of origin of major groups. e. g. the cetaceans. The smallest unit of evolution: one common misconception about evolution is that individual organisms evolve during their lifetime, evolutionary processes (e. g. natural selection) acts no individuals, but populations evolve. Mutation: mutation changes in nucleotide sequence of dna.
