Evolution

mutation
change in DNA sequence that affects genetic information
artificial selection
nature provided variation, humans selected the variations that they found useful
fossil
preserved remains or evidence of an ancient organism
population
group of individuals of the same species that live in the same area
sediments
matter deposited by water or wind
convergent evolution
process by which unrelated things independently evolve similarities when adapting to similar environments
adaptation
any inherited characteristic that increases an organisms chance of survival — ability to respond to change favorably
survival of the fittest
individuals that are the most fit for the environmental conditions survive
common descent
principle that states all living things were derived from common ancestors
homologous structures
structures that have different mature forms but develop from the same embryonic tissues
gene pool
consists of all genes, including all the different alleles, that are present in a population
relative frequency
number of times that the allele occurs in a gene pool, compared with the number of times the other alleles for the same trait occur
single gene trait
controlled by a single gene that has two alleles
polygenic trait
controlled by two or more genes
stabilizing selection
when individuals by the center of the curve have higher fitness than those at either end of it
disruptive selection
occurs when individuals at upper and lower ends have a higher fitness than those in the middle
genetic drift
random change in allele frequencies that occurs in small populations
founder effect
change in allele frequencies as a result of the migration of a small subgroup of a population
fitness
how well an organism can survive and reproduce in its environment
genetic equilibrium
the situation in which allele frequencies remain constant
reproductive isolation
when the members of two populations cannot interbreed and produce fertile offspring
behavioral isolation
when two populations are capable of interbreeding but have differences in rituals or other reproductive strategies
temporal isolation
which two or more species reproduce at different times
extinct(ion)
means the species died out
relative dating
method of determining the age of a fossil by comparing its placement with that of others found in other layers of rock
era
3 of them (Paleozonic, Mesozonic, Cenozonic)
punctuated equilibrium
pattern of evolution when long stable periods are interrupted by brief periods of rapid change
vestigial structure
organ that serves no useful function in an organism
descent with modification
principle that each living thing has descended, with changes, from other species over time
adaptive radiation
rapid growth in the diversity of a group of organisms
divergent evolution
occurs when two or more biological organisms have a common evolutionary origin, and have diverged over time
gradualism
a theory which holds that profound change is a cumulative product of slow, but continuous process
variation
an instance of change or the rate of magnitude of change
co – evolution
the mutual evolutionary influence between two species
common ancestor
an ancient organisms that many more current organisms can be traced back hypothetically through various techniques
absolute dating
a means to date rocks whereby the rate of decay of known mineral is measured over time
natural selection
process by which individuals that are better suited to their environment survive and reproduce most successfully, “survival of the fittest”
directional selection
when individuals at one end of the curve have higher fitness than those in the middle or at the other end
divergence
the process whereby two or more organisms have diverged over time
speciation
the formation of new species over time, many factors can contribute to this