The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. 1857.07.02. I will mainly look at small genera as due to extinction. CUL-DAR165.99. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 8.2023. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR165 contains letters to Darwin: Gaertner - Gurney.

The brown crayon number '22' indicates that this document was filed by Darwin in his portfolio for the subject of Palaeontology: extinction. This note follows from a 1 June 1857 letter from Asa Gray. See CUL-DAR8.47bA. Darwin annotated the letter "Trees & disjoined species"

[1]

July 2d/57/

I will mainly look at small genera as due to extinction─ I look at species with disjoined ranges as due to local extinction, which is first stage to entire extinction─

Therefore as in these cases common cause has been at work, I shd suppose they wd often be identical, ie that species with disjoined ranges wd. occur in small genera.─ (Exclude F.W & marsh Plants & Alpines as special caused have come into play)

Consider list in D. C. work

Asa Gray list smashes it this notion ─ The disjunction is not due to extinction.

Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)