derived traits
characteristics found only in one descendent branch and in the ancestral form
Cladistic
a method of analysis that reconstructs phylogenies by inferrring relationship based on shared characters
Cladogram
a diagram that is based on patterns of shared, derived traits and that shows the evolutionary relationships between groups of organisms
Phylogeny
The study of evolutionary relationships among organisms
Radiometric dating
the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products
Relative dating
method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock
Embryology
The branch of biology that studies the formation and early development of living organisms
Morphology
the branch of biology that deals with the structure of animals and plants
Mass extinction
event in which many types of living things become extinct at the same time
Geologic timescale
records the history of the Earth based on correlations between rocks (or fossils contained in them) and time periods of the past
Speciation
The process by which a new species evolves from a prior species, the most basic process in macroevolution.
Hardy-Weinberg
principle that allele frequencies in a population will remain constant unless one or more factors cause the frequencies to change
Variation
(biology) an organism that has characteristics resulting from chromosomal alteration
Genetic equilibrium
situation in which allele frequencies remain constant
Artificial selection
selection by humans for breeding of useful traits from the natural variation among different organisms
Allele frequency
how often a form of a gene appears in a gene pool
Evolution
a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)
Natural selection
a natural process resulting in the evolution of organisms best adapted to the environment
Acquired traits
charcteristics or behavior not genetic or inherited
vestigial structures
remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.