metamerism

[ muh-tam-uh-riz-uhm ]

noun

1. Zoology.
   1. division into metameres, the developmental process of somite formation.
   2. existence in a metameric state.
2. Chemistry. isomerism resulting from the attachment of different groups to the same atom, as C 2 H 5 NHC 2 H 5 and CH 3 NHC 3 H 7 .

metamerism

/ mɪˈtæməˌrɪzəm /

noun

1. Also calledmetameric segmentationsegmentation the division of an animal into similar segments (metameres). In many vertebrates it is confined to the embryonic nervous and muscular systems
2. chem a type of isomerism in which molecular structures differ by the attachment of different groups to the same atom, as in CH 3 OC 3 H 7 and C 2 H 5 OC 2 H 5

Word History and Origins

Origin of metamerism¹

1840–50; metamerism ( indef 1 ) metamere + -ism; metamerism ( indef 2 ) meta- + (iso)merism

Example Sentences

It’s a phenomenon called observer metamerism.

From Scientific American

The two types of display rely on metamerism, a phenomenon by which combinations of light that look the same actually differ in their spectral make-up, says Lucas.

From Nature

When a creeping plant propagates itself by runners, when a Nais or Myrianida breaks up into a series of similar segments, each of which becomes a worm like the parent, we have to do with the general fact that growing organisms tend to display a symmetrical repetition of equivalent parts, and that reproduction by fission is simply a special case of metamerism.

From Project Gutenberg

We are prohibited by a general consideration of metamerism in the Arthropoda from adopting the hypothesis of intercalation of somites.

From Project Gutenberg

The name “metamerism” has been given to this structural phenomenon because the “meres,” or repeated units, follow one another in line.

From Project Gutenberg