Unit 6 Biology

inherited characteristic that increases an organism's chance of survival

body parts in unrelated species that have common functions, but different anatomical structures; are the result of convergent evolution

the rapidly evolving ability of bacteria to withstand the effects of an antibiotic; is caused by the misuse and overuse of antibiotics

a change in gene frequency following a dramatic reduction in the size of an original population resulting in a loss of genetic diversity

occurs when natural selection favors one of the extreme variations of a trait

form of natural selection that favors individuals at both extremes of the phenotypic range

the change in species/populations over time

any evidence of past life; provide evidence of evolution

loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population

exchange of genes between populations due to the migration of individuals; can be a very important source of genetic variation

all of the genes present in a single species

evolution that occurs due to random change or chance events in small populations

a mechanism of evolution in which members of a species become physically separated from each other and over time become different species

a mistake or change in the normal sequence of DNA; can be random/spontaneous OR caused by radiation, tobacco smoke, and chemical exposure

mechanism by which evolution occurs; when the environment favors a trait an organism with that trait is more likely to survive; AKA "survival of the fittest"

the decreased susceptibility of insects over time to chemicals used to kill them

a branching diagram that shows the evolutionary relationships among organisms based on their DNA; shows common ancestry

the formation of a new species from an existing species

Natural selection that favors intermediate forms by acting against extreme phenotypes

explains how eukaryotic cells evolved from prokaryotic cells

A structure/organ that has little or no purpose in a modern day organism, but may have had a purpose in a distant ancestor; examples include: wings of flightless birds, human appendix & coccyx, and hip bones of whales.