base pair

the four bases in DNA: adenine (A), guanine (G), thymine (T), and cytosine (C). During the replication process, adenine bonds with thymine (A-T), and cytosine bonds with guanine (C-G), if there are no mutations.


paired elements present on both the left and right side of the body, or a condition that effects both sides of the body.


a cusp pattern where ridges (i.e., lophes) are present between the pair of mesial and distal molar cusps.

binomial nomenclature

the scientific name of an organism consisting of two taxonomic terms (i.e., the genus and species name). The binomial nomenclature for modern humans is Homo sapiens.

biological diversity

[syn. biodiversity] the different environments and species on the earth; the genetic variability seen in life.


a form of positional behavior (i.e., posture and locomotion) that utilizes only the hind limbs; an animal that locomotes on two legs is referred to as a biped. See also facultative bipedalism and habitual bipedalism.


arboreal locomotion in which the body is suspended under the hands, legs or tail, and locomotion is propelled by the arms swinging alternately and grasping branches. Apes and humans are able to brachiate.

branching event

a point on the evolutionary lineage of an organism which diverges, or splits off, from the ancestral line into a new evolutionary lineage as a result of numerous unique adaptations.

Broca's area

area of the brain located on the left side of the fontal lobe responsible for the production of speech, including muscle control of the mouth, tongue and larynx.

brow ridge

[syn. supraorbital torus] the bony protrusion above the eye orbit seen in many primates. The brow ridge is very pronounced in Archaic Homo sapiens (i.e., H. heidelbergensis) and H. neanderthalensis.


for premolars and molars, a relative term referring to the part of the tooth that is closer to the cheek, the opposite of lingual.


premolars and molars that have low, rounded cusps.