“TREE OF LIFE”: At the Museum of Science, Darwin’s familiar tale unfolds like a drawing-room detective thriller, complete with magnifying glass. |
One of the coolest parts of the show is the pair of giant live Galápagos tortoises, in bumpy gray-brown shells, that shuffle about on stumpy dinosaur legs. Darwin amused himself by riding these beasts. Nearby is a display of dead Galápagos tortoises that shows how tortoises from one island had “saddlebacked” shells that made it easier for them to reach up and munch tall local cacti while those from another island ate plants close to the ground and so made do with a dome-shaped shell.After sailing on, Darwin noticed that Galápagos mockingbirds differed from island to island too. The differences between finches of the different Galápagos islands were even more apparent, with beaks ranging from short and stout to long and pointy. Back home in England in 1834, he set about figuring out why. Of the many Darwin relics here, among the most striking is a tiny notebook from the late 1830s in which he scribbled “I think” and then a diagram of what looks like a bare twig. It’s an early stab at an evolutionary tree. He’s homing in on the big new idea, and the air is electric.
In 1838, Darwin read an essay about population growth by Thomas Malthus and was struck by the political economist’s idea that limited food supplies restrain the size of human populations. Darwin realized this could apply to critters as well. In 1842, he outlined his idea: plants and animals with advantageous variations were likely to live longer, thus leaving more offspring, some of which would inherit the beneficial traits. Over generations, this process of “natural selection” — his first use of the term — could create new species.
Darwin took his sweet time about breaking the news. That was in part because he feared (correctly) that people would regard evolution as an attack on religion. (A video touches on the continuing religious controversy, but just barely.) In 1842 he moved to quiet Kent, 16 miles outside London, to putter around in his study (lovingly re-created here with Darwin’s actual microscope, chemical bottles, specimen boxes, and work table), garden, and greenhouse. He mulled the breeding of domesticated pigeons, rabbits, cabbages, and gooseberries.
His idyll was shattered in June 1858 when a package arrived from the naturalist Alfred Russel Wallace on the Indonesian island Ternate. Wallace had arrived at his own theory of natural selection, even citing the same passage from Malthus that Darwin had noted. “I never saw a more striking coincidence,” a miserable Darwin wrote to a friend. “All my originality, whatever it may amount to, will be smashed.”
To assert Darwin’s achievement while recognizing Wallace’s, Darwin’s pals arranged for the two men’s papers to be presented jointly to a London scientific society. (Wallace didn’t hear about the event until it was over, but he accepted the arrangement generously.) Then in 1859 Darwin rushed into print with On the Origin of Species: By Means of Natural Selection or The Preservation of Favoured Races in the Struggle for Life. Genuflect before one of only 28 known surviving pages from his original manuscript. Darwin, now a sage fellow with a Father Time beard, followed it up 12 years later with The Descent of Man, which said that we “descended from a hairy quadruped, furnished with a tail and pointed ears.”
