Where does dissimilation collide?

In phonology, dissimilation is a sound change or alternation in which one of two nearby similar or identical sounds is altered so that it becomes less like the other, which is the reverse of assimilation. A classic case involves two liquid sounds such as r or l in one word, where one of them shifts, as when Latin words with repeated liquids passed into the Romance languages with a single liquid changed. Bye's 2011 survey Dissimilation in The Blackwell Companion to Phonology gathered these patterns and the competing theories built to explain them. This meaning is about speech sounds moving apart within a spoken word, not about a cell releasing energy or a migrant community drifting from the majority.[1]

Unit

One sound shifting away from a nearby similar sound, within a word or across a boundary

Recovery means

Not applicable

Measured by

Identified by comparing related word forms and reconstructing the historical or rule-governed change between two similar sounds

In metabolism, dissimilation names the energy-yielding branch of an organism's chemistry: a compound is broken down or transformed mainly to release usable energy, rather than being built into the cell's own material, which is the assimilatory branch. In the nitrogen cycle, for example, microbes can reduce nitrate either to incorporate its nitrogen into biomass (assimilatory) or simply to respire with it and harvest energy (dissimilatory). Kuypers, Marchant, and Kartal's 2018 review The microbial nitrogen-cycling network set out this assimilatory versus dissimilatory division across the cycle. Here dissimilation is a metabolic pathway inside living cells, unrelated to a sound shifting in a word or a community asserting a distinct identity.[2]

Unit

A metabolic transformation that yields energy rather than building biomass, per pathway or per cell

Recovery means

Not applicable

Measured by

Traced by tracking substrates, products, and energy yield, and by labeling atoms to separate energy-harvesting pathways from biomass-building ones

In the study of immigration, dissimilation is the process by which a group, often the children of immigrants, becomes more ethnically distinct rather than blending into the majority, sometimes because official labels and the reactions they meet sharpen a separate identity. It is the counter-process to assimilation, and it can grow across generations instead of fading. Rumbaut's 2005 chapter Assimilation, dissimilation, and ethnic identities traced how second-generation Americans can move toward, and not only away from, a marked ethnic identity. This meaning is about people and cultural belonging, not about consonants in a word or reactions inside a cell.[3]

Unit

A shift of a group or generation toward a more distinct ethnic identity

Recovery means

Not applicable

Measured by

Assessed through surveys of ethnic self-identification and panethnic labels, and their change across immigrant generations