Friday, August 7, 2015

Adventure classics – Before finches, Darwin had fossils

The Voyage of HMS Beagle
by Charles Darwin
Who hasn’t heard about Charles Darwin’s collection of Galapagos finches? But who gives credit to the fossil finds of South America for their part as muses to the father of evolutionary biology?

Not even Darwin realized the importance of the fossils he first encountered in 1833, not quite two years into the adventure that had saved him from life as a clergyman, the fallback profession of 19th century middle-class young Englishmen. After giving up on the study of medicine (the sight of surgeries performed without aid of then unheard of anesthetics made him sick), he managed to complete a university course of study (although without honors), the prerequisite for a career in the church.

In fact, he spent most of his time at university riding, shooting, and collecting insects, activities that would prepare him admirably for work as a scientist/explorer of the time, however questionable they might have been for a priest of the Church of England. And it was at Cambridge that he met others interested in “natural sciences” such as biology, including clergymen/naturalists Adam Sedgwick and Leonard Jenyns.

Sedgwick and Jenyns had received invitations to accompany the Royal Navy’s HMS Beagle on a survey mission of the coasts of South America. Both declined due to other commitments, although it’s easy to imagine a reluctance of each to be the gentleman-companions of the Beagle’s short-tempered Captain Robert Fitzroy playing some part in their refusals. And then they remembered their young friend. Despite the opposition of his father (another career change, Charles?), Darwin accepted the invitation with alacrity, setting sail on December 27, 1831, for a voyage that would change his life and the world.

Official, he was the Beagle’s geologist. With the scientific world agog over a new theory of geologic change proposed by Charles Lyell, Darwin packed a copy of Lyell’s Principles of Geology to prep for his new job. He would later dedicate his own first book to the Scottish geologist.

Lyell’s theory of the gradual change of the Earth over time was at odds with the prevailing doctrine of catastrophic change. But Darwin found that Lyell’s theory helped explain his observations of the ship’s early stops at the Canary and Cape Verde islands fringing the Atlantic coast of Africa. As the Beagle coasted around South America, Darwin plunged into geology with a vengeance.

“The Beagle arrived (in Argentina) on the 24th of August,” he noted in his journal. “With Captain Fitz Roy’s consent, I was left behind, to travel by land to Buenos Ayres. . . (including a section) highly interesting from the number and extraordinary character of the remains of gigantic land-animals embedded in it.”

Among these were fossils whose size first led Darwin to believe they were rhinoceros. They were later identified as species of extinct giant ground sloths. One would later be named Mylodon darwinii after its discoverer.

Collecting fossils as gleefully as he did everything else, including an attempt to use the bola weapon of the South American gauchos he rode with, he moved on. Galapagos and its finches were still in the future and it would be years more before he began to unravel the mystery of the giant bones.

(Next Friday, Adventure classics continues an August of adventures at sea with Darwin’s Voyage of HMS Beagle.)

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