20 terms

Biology: Ch. 13

artificial selection
selecting and breeding individuals that possess desired traits
fossil record
sequence in which fossils appear within layers of sedimentary rocks
geographic distribution of species
similarity in characteristics that results from common ancestry
vestigial organs
structures that are of marginal or no importance to organism
group of individuals in same species living in same place at same time
gene pool
total collection of genes in a population at any time
change in the nucleotide sequence of DNA
bottleneck effect
genetic drift from drastic reduction in population size, surviving population no longer representative of original population
founder effect
genetic drift when few individuals isolated from larger population, composition of new population's gene pool not reflective of original population
sexual dimorphism
marked differences between secondary sex characteristics of males and females
sexual selection
form of natural selection where individuals with certain characteristics more likely than other individuals to obtain mates
balancing selection
natural selection maintains stable frequencies of two or more phenotypic forms in population
heterozygous advantage
heterozygous individuals have more reproductive success than homozygotes
relative contribution an individual makes to the gene pool of next generation
descent with modification
all life is connected by common ancestry, descendants have accumulated adaptions to changing environments over time
hardy weinberg equilibrium
allele and genotype frequencies of a population remain constant if population is large, mating is random, and no mutation, gene flow, or natural selection
antibiotic resistance
directional selection resulting from excessive or incorrect use of antibiotics
preservation of variation
variation preserved by hiding recessive alleles