Definition of homeosis in US English:


(British homoeosis)

nounPlural homeoses

  • The replacement of part of one segment of an insect or other segmented animal by a structure characteristic of a different segment, especially through mutation.

    • ‘Genes identified by such mutations are called homeotic genes because when mutated they result in homeosis - the transformation of a whole segment or structure into another related one, as in the transformation of antenna to leg.’
    • ‘This research on homeosis was intended to support both his view of genetic structure and his view of evolution.’
    • ‘Even when the case for a pattern of homeosis is more firmly established, the underlying mechanism responsible for the pattern is not easily accessible.’
    • ‘He used examples such as environmental sex determination and homeosis as possible examples.’
    • ‘However, those experiments show only what morphological changes are possible to manipulate experimentally, not what actually happened in evolution, and one question is why homeosis would occur at all.’


Late 19th century: from Greek homoiōsis ‘becoming like’, from homoios ‘like’.