Being of the same typical structure; having like relations to a fundamental type to structure; as, those bones in the hand of man and the fore foot of a horse are homologous that correspond in their structural relations, that is, in their relations to the type structure of the fore limb in vertebrates.
similar body parts in different species as a result of descent from a common anscestor
Nucleic acid molecules with the same base sequence except for minor differences in alleles; (ii) nucleic acid molecules originating from strains of the same species, thus having at least long stretches of identical DNA base sequences; (iii) gene or protein families having a recognizable common evolutionary origin.
a correspondence of two organs in structure, position, and origin
In phylogenetics, describing particular features in different individuals that are genetically descended from the same feature in a common ancestor. In molecular biology, often "homologous" simply means similar, regardless of genetic relationship.
Shared by virtue of inheritance from a common ancestor. A character or character state shared by two organisms (which may represent different species or clades) is said to be homologous if that character or character state was present in all of their ancestors back to and including their most recent common ancestor.
corresponding, as in relative position or structure; a homologous tumor is made up of cells resembling those of the tissue in which it is growing
Pertaining to DNA molecules that have identical or nearly identical base sequences.
derived from tissue or DNA of a member of the same species.
corresponding in origin, structure, and position.
corresponding in structure, such as homologous antigens.
Describing the relationship between a pair of structures or processes that show a fundamental similarity because of their having descended from a common ancestor. Homologous structures in related species have the same evolutionary origin although their functions may differ widely: e.g. the flipper of a seal and the wing of a bat. Homologous genes in a genome share a similar DNA base sequence because they arose by duplication of an ancestral gene.
Descended from a common ancestor. Defined in 1843 by Richard Owen, the British Palaeontologist as the "same organ under every variety of form and function". For molecular sequence data, it is taken to mean that two sequences or even two characters within sequences are descended from a common ancestor. This term is frequently mis-used as a synonym for 'similar', as in "two sequences were 70% homologous". This is totally incorrect! Sequences show a certain amount of similarity. From this similarity value, we can probably infer that the sequences are homologous or not. A statement that is attributed to Walter Fitch is that (I'm prarphrasing here) homology is like pregnancy. You are either pregnant or not, two sequences are either homologous or they are not.
In phylogenetics, describing particular features in different individuals that are genetically descended from the same feature in a common ancestor. In molecular biology, homologous sequences often mean significantly similar sequences that are highly likely to have a common descent.
having the same evolutionary origin but serving different functions; "the wing of a bat and the arm of a man are homologous"
From the same source, or having the same evolutionary function or structure.
A pair of genes, traits, or structures from different, but related, species from a common ancestral organism which are identical or very similar to each other. The shared commonality may not necessarily perform the same functions in each organism, nor perform the functions it did in the common ancestor. Back to glossary index
description for physical features that are formed in similar ways during embryonic development and that have a similar structure (e.g., the flipper of a whale, the arm of a human and the wing of a bat are all homologous organs)
Similar in position, structure, function, or characteristics.
Resulting from a common ancestry, or of the same orgin.
Corresponding or alike in structure, position, or origin.
similarity in the sequence of a protein or nucleic acid or in the structure of an organ that reflects a common evolutionary origin. Molecules or sequences that exhibit homology are referred to as homologs. In contrast, analogy is a similarity in structure or function that does not reflect a common evolutionary origin. (Molecular Cell Biology/Harvey Lodish [et al.] - 4th)
similar in appearance, structure and usually function. For HIV, the same strain of the virus.
Similar in appearance or structure, but not necessarily function.
Regions of DNA molecules that have the same nucleotide sequence.
same structure serving different functions. e.g., elephant's front legs and bats wings (compare with analogous)
Homologous chromosomes have corresponding DNA sequences and come from separate parents.
