neomorphn.
/ˈniːə(ʊ)mɔːf/, U.S. /ˈnioʊˌmɔrf/ 1. Biology. An anatomical structure or feature that has arisen during phylogeny as a new development, rather than by derivation from earlier features; a structure that does not have a homologue in earlier forms.
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the world > life > biology > biological processes > evolution > [noun] > morphogenesis > derivation or appearance of characters
acquired1794
neomorph1886
paedomorphism1892
neotenia1896
habitat form1902
caenogenesis1909
fetalization1922
paedomorphosis1922
hominization1953
synapomorphy1966
synapomorph1969
1886 W. N. Parker tr. R. Wiedersheim Elements Compar. Anat. 33 It is uncertain whether the dermal skeleton present in Armadillos..is to be derived directly from that of Reptiles, or whether it is to be considered as formed independently, that is, as a new acquisition or ‘neomorph’ (Gadow).
1906 Amer. Naturalist 40 80 There is, at the present time, abundant evidence to show that the functional mouth of the vertebrate of to-day is a neomorph.
1956 A. S. Romer Osteol. Reptiles vii. 328 In this case [sc. of the pterosaur skeleton] the majority opinion is that the true pubis is included in the plate and that this anterior element is a neomorph, a prepubis.
1998 Zool. Jrnl. Linn. Soc. 124 43 The postspinal lamina, on the neural spines of middle and caudal dorsal vertebrae [of fossil sauropods], represents a neomorph rather than a fusion of pre-existing structures.
2. Genetics. A mutant allele that produces an effect qualitatively different from that of the wild-type allele.
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the world > life > biology > biological processes > genetic activity > genetic components > [noun] > allele > types of allele
dominant1900
unit character1902
multiple allelomorph1913
lethal1917
marker1930
multiple allele1930
amorph1932
hypomorph1932
neomorph1932
isoallele1943
hypermorph1949
1932 H. J. Muller in Proc. 6th Internat. Congr. Genetics I. 245 Somewhat different from the negatively acting, competing mutant genes, or antimorphs, is the class which I am provisionally terming ‘neomorphs’. A good example is the dominant mutant, Hairy wing, near the left end of the X chromosome.
1946 Nature 12 Oct. 520/1 Among spontaneous mutations which are known to occur at this locus some would be expected to be neomorphs.
1967 Evolution 21 850 (title) Latent neomorphs and the evolution of dominance.
1988 Mouse News Let. Nov. 133 A radiation-induced deletion covering the T locus and the proximal distorter..produced an effect resembling that of t rather than wild-type, and hence the proximal distorter is not a neomorph.
1998 Proc. National Acad. Sci. U.S.A. 95 10036/2 One or the other of these genes could have evolved as a neomorph.
This entry has been updated (OED Third Edition, September 2003; most recently modified version published online March 2022).
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n.1886