BIOL 1202 Chapter : Chapter 23 Biology
Document Summary
One common misconception about evolution is that individual organisms evolve during their lifetime. Evolutionary processes (e. g. natural selection) acts on individuals, but populations evolve. Mutations: changes in nucleotide sequence of dna: source of new alleles and genes. Point mutation: change in one nucleotide base in a gene. Chromosomal mutation: delete, disrupt, or rearrange many loci on a chromosome. Gene duplications: duplication of whole segments of chromosomes. Mutation rate averages 1 in every 100,000 genes per generation. In sexually reproducing organisms, sexual recombination produces most of the variability in each generation. Discrete characters: classified on an either/or basis: e. g. flower color in pea plants. Quantitative characters: vary along a continuum within a population: e. g. height, weight. Concept 23. 2: the hardy-weiberg equation can be used to test whether a population is evolving. Population: a group of individuals of the same species living in a certain defined area. H-w equlibrium: describes a population that is not evolving (i. e. allele frequencies don"t change)
