Bergmann's rule

noun

Berg·​mann's rule

ˈbərg-mənz,

ˈberg-

: a statement of the principle that within a polytypic wide-ranging species of warm-blooded animals the average body size of members of each geographic race varies inversely with the mean environmental temperature

Word History

Etymology

after Karl Bergmann †1865 German biologist

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!