Download EVOLUTION Hereditary changes in groups of living organisms over

EVOLUTION Hereditary changes in groups of living organisms over time.
NATURALSELECTION A theory of evolution developed by Darwin, based on four ideas: excess
reproduction, variations, inheritance, and the advantages of specific traits in an environment.
ANALOGOUS A structure that has the same function but different construction, and was not inherited
from a common ancestor.
FOSSILRECORD Evolutionary thinkers feel this “record” provides strong direct evidence to support
evolution.
VESTIGIAL The type of structure that is a reduced form of a functional structure, which evolutionists feel
indicates shared ancestry.
HOMOLOGOUSSTRUCTURE An anatomically similar structure inherited from a common ancestor, so it is
thought.
CAMOUFLAGE An adaptation that allows an organism to blend into its surroundings.
ADAPTATION An inherited characteristic of a species that develops over time in response to an
environmental factor, enabling the species to survive.
ADAPTIVERADIATION The diversity of a species into a number of different species, often over a relatively
short period of time.
HARDYWEINBERG This principle describes conditions within which evolution does not occur; it has a
special formula which shows how allele frequencies in populations stay the same unless they are
affected by a factor that causes change.
BOTTLENECK The process in which a large population declines in number, then rebounds.
DIRECTIONAL This ‘selection’ indicates that there is a shift of a population toward an extreme version of
a beneficial trait.
FOUNDEREFFECT A random effect that can occur when a small population settles in an area separated
from the rest of the population and interbreeds, producing unique allele variations.
FOSSIL Preserved evidence of an organism, often found in sedimentary rock, that provides evidence of
past life.
DISRUPTIVE A type of ‘selection’ in which individuals with average traits are removed, creating two
populations with extreme traits.
GENETICDRIFT A random change in allelic frequencies in a population.
GRADUALISM The theory that evolution occurs in small, gradual steps over time.
PUNCTUATED This “equilibrium” is a theory that evolution occurs with relatively sudden periods of
speciation followed by long periods of stability.
SPECIATION The evolutionary process by which new isolated kinds of organisms (species) happen.
SPECIES A group of organisms that can interbreed and produce fertile offspring.
OPPOSABLE When a “thumb” can touch any of the other fingers, it is said to be this; primates have
them.
BIPEDAL An organism (such as a primate) that can walk on two legs is called this.
HOMO The genus that we human beings belong to.
AUSTRALOPITHECUS The supposed ancestor of the genus Homo, “Lucy” is the most-common fossil of
this type, which follows the out-of-Africa hypothesis.