Definition of homology
plural homologies
1
: a similarity often attributable to common origin
2 a
: likeness in structure between parts of different organisms (such as the wing of a bat and the human arm) due to evolutionary differentiation from a corresponding part in a common ancestor — compare analogy
b
: correspondence in structure between a series of parts (such as vertebrae) in the same individual
3
: similarity of nucleotide or amino acid sequence (as in nucleic acids or proteins)
4
: a branch of the theory of topology concerned with partitioning space into geometric components (such as points, lines, and triangles) and with the study of the number and interrelationships of these components especially by the use of group theory — called also
homology theory; compare cohomology
