Darwin last article

The Castilla del oro foundation in panama

Darwin’s last article

Madrid, September 2011

The Castilla del Oro Foundation, led by Richard Fifer-Carles and chaired by Cristobal Colon in Spain will develop an important social and environmental labor in the area of Cerro del Andevalo –Huelva. In this line comes the concern about environmental issues, this time, we will tackle nature conservation.

The Famous naturist

On April 19, 1882, at 73 years of age, Darwin passed away in his beautiful country mansion in Down House. Just two weeks before, on April 6, the weekly magazine Nature had published his last work, a note titled “About the dispersion of the fresh water bivalves”. Darwin started by pointing out the great similarity that, in some very distant regions, have these and other species that live in fresh water, in contrast to the great differences exhibited by land animals, even though each river basin is independent from its neighbor. The famous naturalist had already discussed this topic on the thirteenth chapter of the Origen of Species. There, he attributed such similarities to changes on the ground levels which originated the rivers to pour into one another and, in the case of the fresh water mollusks, also to their dispersion by means of aquatic birds. To this effect he told his experience with a duck he placed in an aquarium where there have been incubated mollusk eggs, without specifying the species. A great number of young individuals stuck to the duck’s feet and survived there between 12 and 20 hours, time when, according to Darwin, the bird could have flown one thousand kilometers.

On his last note, Darwin made reference to another collaboration about the same topic already published four years before in Nature, on May the 30^th of 1878, this time under the title “Shell Movement”. After the publication of the Origin of Species, Darwin received letters from all over the world and that note from 1878 made reference to one sent by an American called Arthur Gray, who offered a prove to corroborate his idea that fresh water clams could be transported by aquatic birds. It was a drawing of the leg of a blue-winged teal (Anas Discors) hunted at a Massachusetts river with one of those clams stuck to a finger, in concrete a specimen of Unio Complanatus, possibly misidentified since this species is European. In any case, the clam was alive when the teal was taken.

Meanwhile, the note from 1882 was referring to another letter that told something similar, only now the spreading agent wasn’t a bird, but a beetle, and the clam belonged to another great family of bivalves that, with the naiads, had colonized the fresh waters: the tiny spherical. Darwin’s correspondent was this time a Walter Crick, a shoemaker from North Hampton fond of Natural Sciences and fossil collector. About him should be said that he had a grandson called Francis Crick, whom he never met, who published in 1953 in Nature a two page article that awarded him the Nobel Prize on Medicine in 1962, which he shared with this collaborator James Watson, the topic was regarding the structure of DNA, molecule on which sequence are produced the mutations and which contains the intimate substratum of the individual variation and, thus, the evolution of the species by natural selection.