a specific sequence of nucleotides in DNA or RNA that is the unit of inheritance specifying the structure of a protein.

gene flow

the transfer of genes from one population to another; contributes to genetic diversity.

gene frequency

percentage of a certain form of gene within a population in relation to the total forms that could possibly be expressed in genes.

generalized trait

a trait not adapted to a specific environment or niche.

genetic drift

an accidental shift in gene allele frequencies.


all the hereditary information (i.e., genetic make-up) of an organism that is encoded in DNA.


genetic material; the combination of alleles that make up an organism's DNA; entirely hereditary.


in taxonomic classification, describes a group of organisms that all belong to the same family but not to the same species. Populations within the same genus are related but incapable of successful interbreeding.


the period between fertilization of the ovum and birth.


characterized as being small bodied or has lightly-constructed anatomy; the opposite of robust.


[syn. clade] a group organisms with similar characteristics that may or may not depict evolutionary relationships.

gradistic classification

a way to classify organisms based on grade as opposed to ancestry.

greater apes

refers to the gorilla, chimpanzee, and orangutan.