Darwin’s Birthday

Happy Birthday, Charles Darwin

Darwin hanging from a tree

La Petite Lune, 1871

February 12, 2015 marks the 206th birthday of naturalist Charles Darwin, whose lifelong work established the scientific theory that all species of life have descended over time from common ancestors through a branching pattern of evolution. The Arnold Arboretum celebrates the life and achievements of one of the foremost thinkers in science.

Darwin’s quotations about trees

 
In the last number of Nature (vol. xiv , p 10), Mr. Pryor states that the flowers of the wild cherry are bitten off in large numbers in much the same manner as I formerly described in the case of the primrose. Some days ago I observed many cherry blossoms in this state, and to day I saw some actually falling I approached stealthily so as to discover what bird was at work, and behold it was a squirrel. There could be no doubt about it for the squirrel was low in the tree and actually had a blossom between its teeth. It is none the less true that birds likewise bite the flowers of the cherry tree.
From Nature. A Weekly Illustrated Journal of Science, “Cherry blossoms,” 1876
 
It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us.
On the Origin of Species, 1859
 
I found a clump of petrified trees, standing upright, with the layers of fine Sandstone deposited round them, bearing the impression of their bark. These trees are covered by other Sandstones & streams of Lava to the thickness of several thousand feet. These rocks have been deposited beneath water, yet it is clear the spot where the trees grew, must once have been above the level of the sea, so that it is certain the land must have been depressed by at least as many thousand feet, as the superincumbent subaqueous deposits are thick.— But I am afraid you will tell me, I am prosy with my geological descriptions & theories.
Letter to Susan Elizabeth Darwin, April 23, 1835

Darwin Correspondence Project

Darwin Correspondence Project

The Darwin Correspondence Project provides access to at least 15,000 letters, written between 1821 and 1882, and “Darwin & Gender” is the newest feature to reveal his accomplishments and complexities.
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“You ask about my doctrine which led me to expect that Trees would tend to have separate sexes.  I am inclined to believe that no organic being exists which perpetually self-fertilises itself. This will appear very wild, but I can venture to say that if you were to read all my observations on this subject, you would agree it is not so wild as it will at first appear to you, from flowers said to be always fertilised in bud &c &c &c.— It is a long subject to which I have attended to for 18 years!
Letter to Asa Gray, after March 15, 1857
 
“I am taking “Weeping trees”, as an example how inexplicable the laws of inheritance are; some weeping trees reproducing themselves almost truly by seed, & some quite failing to do so.”
Letter to Thomas Rivers, Feb 1, 1863
 
In plants the down on the fruit and the colour of the flesh are considered by botanists as characters of the most trifling importance: yet we hear from an excellent horticulturist, Downing, that in the United States smooth-skinned fruits suffer far more from a beetle, a curculio, than those with down; that purple plums suffer far more from a certain disease than yellow plums; whereas another disease attacks yellow-fleshed peaches far more than those with other coloured flesh. If, with all the aids of art, these slight differences make a great difference in cultivating the several varieties, assuredly, in a state of nature, where the trees would have to struggle with other trees and with a host of enemies, such differences would effectually settle which variety, whether a smooth or downy, a yellow or purple fleshed fruit, should succeed.
On the Origin of Species, 1859
 
In treatises on many kinds of cultivated plants, certain varieties are said to withstand certain climates better than others: this is very strikingly shown in works on fruit trees published in the United States, in which certain varieties are habitually recommended for the northern, and others for the southern States; and as most of these varieties are of recent origin, they cannot owe their constitutional differences to habit.
On the Origin of Species, 1859
 
Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. But analogy may be a deceitful guide. Nevertheless all living things have much in common, in their chemical composition, their germinal vesicles, their cellular structure, and their laws of growth and reproduction. We see this even in so trifling a circumstance as that the same poison often similarly affects plants and animals; or that the poison secreted by the gall-fly produces monstrous growths on the wild rose or oak-tree. Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.
On the Origin of Species, 1859

Did you know?

One of the most famous quotations attributed to Darwin was not originally his idea? “Survival of the fittest” was first coined by the early evolutionist and polymath Herbert Spencer in 1864. Darwin then used this phrase, with attribution, in the fifth and sixth (final) editions of On the Origin of Species.

Related Links

Arboretum Library Holdings

On the Origin of Species
The different forms of flowers on plants of the same species (HOLLIS)