Term | Definition |
evolution | the change in allele frequency of a population over time [B] |
natural selection | the process by which organisms that are better adapted to their environment are more likely to survive and reproduce (mechanism for evolution) [B] |
adaptation | a genetic variation (expressed as a trait) that is favored by selection in a particular environment [B} |
species diversity | the number of different species in a particular area [B] |
limited resources | less available food, water or space than is required by a population (above the carrying capacity) [B] |
competition | struggle for existence between organisms for mates or limited resources (winners are more fit, better adapted) [B] |
genetic variation | the difference in alleles or genes between organisms within the gene pool of a species [B] |
mutation | this change in DNA (nucleotide sequence) is the original source of variation [B] |
genotype and phenotype | 1) the 2 alleles (ex: Ww) for a trait
2) the expression of a trait (ex: widow's peak) [B] |
speciation | the formation of a new species following reproductive isolation (results in species diversity) [B] |
evidence of evolution | includes, but is not limited to fossil record, morphological homologies and DNA/protein similarities [B] |
common ancestor | an ancestral species shared by two or more species as evidenced by commonalities (can be shown on a phylogenetic tree or cladogram) [B] |
genetic drift | changes in the gene pool of a small population due to chance (examples include a bottleneck and the founder effect) [BB] |
radioactive dating | a method of determining the age of fossils and rocks using half-lives of radioactive isotopes (example: carbon dating) [BB] |
mutagen | causes mutations in DNA (includes radiation, some metals and biological agents) [BB] |
heterozygous advantage | preserves variation in gene pools by greater reproductive success in heterozygotes over individuals homozygous for either of the associated alleles (example: sickle cell allele and malaria resistance) [BB] |
reproductive isolation | two populations whose members are distinct species since they are blocked from interbreeding and producing fertile offspring (example: geographical isolation) [BB] |
gene pool | the total collection of genes in a population at any one time [BB] |
Charles Darwin | an English naturalist and geologist, best known for his contributions to evolutionary theory [BB] |
evolutionary fitness | for each individual this is measured by reproductive success due to use of inherited adaptations [BB] |
extinction | the end of life for all members of a species (a lack of genetic variation can increase the chance of this occurring) [BB] |
morphological homologies | similarity between two species in their form and structure of the whole organisms or their parts (including vestigial organs) [BB] |
adaptive radiation | the emergence of numerous species from a common ancestor introduced into an environment (often seen on islands) [BB] |
Miller-Urey experiment | showed the possibility of making complex organic molecules from inorganic molecules in the simulated conditions (as understood in 1953) of early Earth. [BB] |
Hardy-Weinberg equilibrium | the absence of evolution if all of the following 5 conditions are true: large populations, no mutations, no migration, random mating and no selection [Lab: Mathematical Modeling] |
Hardy-Weinberg equations | p2 + 2pq + q2 = 1 and p + q = 1 [Lab: Mathematical Modeling] |
q | allele frequency of the recessive allele (or second allele) in a population [Lab: Mathematical Modeling] |
p | allele frequency of the dominant allele (or first allele) in a population [Lab: Mathematical Modeling] |
2pq | the frequency of the heterozygous genotype in a population [Lab: Mathematical Modeling] |
p2 | the frequency of the homozygous dominant genotype in a population [Lab: Mathematical Modeling] |
q2 | the frequency of the homozygous recessive genotype in a population [Lab: Mathematical Modeling] |
allele frequency | The proportion of a particular allele in a population (written as a decimal) [Lab: Mathematical Modeling] |
artificial selection | The selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits. [Lab: Artificial Selection] |
bar graph | uses rectangles of different heights to characterize data that is categorical (example: # of plants with different ranges of trichomes) [Lab: Artificial Selection] |
trichomes | hair-like structures found on plants (functions include, defense, lowering plant temperature and water absorption) [Lab: Artificial Selection] |
directional selection | a type of natural selection for a multigenic trait that favors individuals on one end of the phenotypic range (graphically shown as shift to the left or right) [Lab: Artificial Selection] |
inherited trait | a trait or characteristic that is passed through DNA from one generation to the next [Lab: Artificial Selection] |
life cycle | The entire sequence of stages in the life of an organism, from the adults of one generation to the adults of the next [Lab: Artificial Selection] |
generation | all individuals of a species born and living at about the same time (examples: P, F1, F2, etc.), [Lab: Artificial Selection] |
BLAST | a program that searches for regions of similarity between a biological sequence (DNA or proteins) and a genome database of many species [Lab: BLAST] |
cladogram | phylogenetic tree that branches repeatedly, suggesting a classification of organisms based on the time sequence in which evolutionary branches arise. [Lab: BLAST] |
derived characteristics | a trait that is shared by organisms with a recent common ancestor. (can be listed on a cladogram) [Lab: BLAST] |
morphological characteristics | traits that refer to structure or form such as shape, length or color of the body [Lab: BLAST] |
DNA comparison | a percent comparison of the DNA code of genes between two different species (can use BLAST) [Lab: BLAST] |
protein comparison | a percent comparison of the proteins between two different species (can use BLAST) [Lab: BLAST] |
nucleotide sequence | the order of the nucleotides (A,G,T and C) within a gene [Lab: BLAST] |