I've written before about why Origin is so important - On the Origin of Species: still going strong - so this time I'm just going to leave you with another one of my favorite passages:
Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change, to the beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection.
Part of the genius of Origin is how meticulously Darwin builds his argument, pedagogically bringing together many lines of evidence by using examples that are well known to the reader. In this passage from chapter 4 (beautifully written, it must be said), Darwin anticipates arguments against the thought that such a simple and elegant idea as natural selection could underlie the vast complexity of the natural world, and demonstrates his point by bringing out the example of human-directed artificial selection, something that by his time was well known among plant and animal breeders.
Later in Origin, in chapter 13, he once again uses artificial selection to make the point that all living organisms are united by a common origin.
As the evidence appears to me conclusive, that the several domestic breeds of Pigeon have descended from one wild species, I compared young pigeons of various breeds, within twelve hours after being hatched; I carefully measured the proportions (but will not here give details) of the beak, width of mouth, length of nostril and of eyelid, size of feet and length of leg, in the wild stock, in pouters, fantails, runts, barbs, dragons, carriers, and tumblers. Now some of these birds, when mature, differ so extraordinarily in length and form of beak, that they would, I cannot doubt, be ranked in distinct genera, had they been natural productions. But when the nestling birds of these several breeds were placed in a row, though most of them could be distinguished from each other, yet their proportional differences in the above specified several points were incomparably less than in the full-grown birds.
It's this keen observational skill, clarity and untiring curiosity that continues to be an inspiration 150 years on.
Swedish blog tags: Vetenskap, Evolution, Biologi, Darwin, Om arternas uppkomst
Technorati tags: Science, Evolution, Biology, Darwin, On the origin of species