Meanings
- An ecogeographic rule describing the inverse relationship between water temperature and meristic characteristics in various species of fish, including the fact that fin ray, vertebrae, or scale numbers increase with decreasing temperature.
- An ecogeographic rule stating that, given any species in any region, the nearest related species is not likely to be found in the same region nor in a remote region, but in a neighbouring district separated from the first by a barrier of some sort.
Synonyms: Jordan's law
Synonyms & antonyms
proper nounAn ecogeographic rule stating that, given any species in any region, the nearest related species is not likely to be found in the same region nor in a remote region, but in a neighbouring district separated from the first by a barrier of some sort.
Origin
Named after American scientist David Starr Jordan (1851–1931).
Full word history & related roots →Cite this entry
Jordan's rule. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/Jordan's%20rule
“Jordan's rule.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/Jordan's%20rule. Accessed November 4, 2026.
WatkinsX Dictionary, s.v. “Jordan's rule,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/Jordan's%20rule.
Source: Jordan's rule on Wiktionary, CC BY-SA 4.0.