From J. D. Hooker [11 May – 3 December 1860]1
reducing individuals here & destroying genera elsewhere— Whether man reduces the bulk of organic & increases that of inorganic matter or no there cannot be a doubt that his influence is devoted to reducing existing species & hence improving our means of classification, which is only another expression for, further sundering allied forms—2 The number of new varieties he creates are as nothing to the destruction of old & the reduction of the battle field for the remainder.— the struggle is hence all the harder in the space he leaves to native vegetation.3 Man & his intellect are all part of the scheme & must not be shirked. Still the question makes me giddy from its complication.
I think little of his objection on the score of varieties of the lineal descendent of A. becoming confounded with those of ⟨B⟩4 no doubt such cases occu⟨r⟩ I have somewhere I think alluded to them as very probably frequent. ⟨I should⟩ now put into this category all those anomalous plants which hover between two otherwise very remote species in genera or families.5 It struck me that such cases were well explained by your divergent series—6 Such cases if decided ones should be rare— so they are— There is however the perpetual difficulty of deciding between reversion of character & persistence of character. Let us suppose that Dicots. were developed through & after Monocots, & regard Conifers as anomalous Dicots nodding towards Cryptogams & we have a case in point,— the Conifers are either Dicots that vary towards Cryptogs. or (as I should incline to suppose) a sub series of Dicots. developed parallely to the main Monocot branch, but in which alone ⟨ ⟩ the Cryptog. characters persisted 7 Watson must think that subsequent variation may as easily be towards8 the old type as away from it— this is conceivable of course, but I maintain it is not so in nature— it is opposed to my idea of centrifugal variation.—9 Now variation is not centrifugal because of any repulsive or repellent power, but simply because in fact it is a million chances to one that identity of form once lost will be returned to.10 Each character we estimate is a compound of lesser characters each too minute to estimate in the gross, but missed if with-drawn. A petal if further varying after it has once varied has a thousand characters of form color consistence nervation &c &c &c to chuse amongst (so to speak) besides those its grandparents bore. After all, experience is our best guide, & we do not find in the human race any reversion so strong as would lead us to confound a man with his ancestor, a Yankee with an Englishman— Whoever saw a Grandfathers portrait that would really pass for his Grandsons—& if we do not find reversion amongst individuals so close in kin & in time, how can we expect them in organisms that have reached the specific term of divergent development—
True you may have a 10th removed lineal descendent (who supposing the name of Wedgwood to be lost to genealogists—except by a stray portrait) may so resemble the Wedgwood portrait that an Ethnologist would call him an anomalous Darwin representing the lost Wedgwood type.—but the chances are a hundred to one in favor of both Wedgwood & Darwin physiognomy being wiped out long before the 10th. generation—11 How often do we consider 2 people strikingly alike till we see them together & then consider them wholly unlike; this is because one minute character common to both was alone carried away, in the mind, but which, though no doubt present, is not perceived when again sought for amongst the thousand other characters of the 2 faces.
CD annotations
Footnotes
Bibliography
Wedgwood, Barbara and Wedgwood, Hensleigh. 1980. The Wedgwood circle, 1730–1897: four generations of a family and their friends. London: Studio Vista.
Summary
CD’s divergent series explains those anomalous plants that hover between what would otherwise be two species in a genus.
Inclined to see conifers as a sub-series of dicotyledons that developed in parallel to monocotyledons, but retained cryptogamic characters.
Mentions H. C. Watson’s view of variations.
Man has destroyed more species than he has created varieties.
Variations are centrifugal because the chances are a million to one that identity of form once lost will return.
In the human race, we find no reversion "that would lead us to confound a man with his ancestors".
Letter details
- Letter no.
- DCP-LETT-3036
- From
- Joseph Dalton Hooker
- To
- Charles Robert Darwin
- Sent from
- unstated
- Source of text
- DAR 205.5: 217 (Letters), DAR 47: 214
- Physical description
- inc †
Please cite as
Darwin Correspondence Project, “Letter no. 3036,” accessed on 6 October 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-3036.xml
Also published in The Correspondence of Charles Darwin, vol. 13 (Supplement)