Thursday, September 04, 2008

The Torch of Evolution

I had meant to look this up before I went to the Galapagos earlier this year. I stumbled across it this morning, so I wanted to mention it here.

It's a passage from Nathaniel Philbrick's book "In the Heart of the Sea: The Tragedy of the Whaleship Essex," a historical account of the sinking of a whale ship that probably inspired some of the story line for Melville's Moby-Dick. At one point the Essex stops in the Galapagos to gather some tortoises for food. Having taken 180 tortoises from tiny Hood Island (now Isla EspaƱola) in four days, they headed to nearby Charles Island (now called Santa Maria, or Floreana, depending on who you listen to), where they picked up a 600-pound tortoise that took six men to carry.

But on their last day on the island this went awry:
On the morning of October 22, Thomas Chappel, a boatsteerer from Plymouth, England, decided to play a prank. Not telling anyone else on the Essex what he was up to, the mischievous Chappel (who was, according to Nickerson, "fond of fun at whatever expense") brought a tinderbox ashore with him. As the others searched the island for tortoises, Chappel secretly set a fire in the underbrush. It was the height of the dry season, and the fire soon burned out of control, surrounding the tortoise hunters and cutting off their route back to the ship. With no other alternative, they were forced to run through a gauntlet of flame. Although they singed their clothes and hair, no serious injuries resulted--at least not to the men of the Essex.

By the time they returned to the ship, almost the entire island was ablaze. The men were indignant that one of their own had committed such a stupid and careless act. But it was Pollard who was the most upset. "[T]he Captain's wrath knew no bounds," Nickerson remembered, "swearing vengeance upon the head of the incendiary should he be discovered." Fearing a certain whipping, Chappel did not reveal his role in the conflagration until much later. Nickerson believed the fire killed thousands upon thousands of tortoises, birds, lizards, and snakes.

The Essex had left a lasting impression on the island. When Nickerson returned to Charles years later, it was still a blackened wasteland. "Wherever the fire had raged neither trees, shrubbery, nor grass have since appeared," he reported. Charles would be one of the first islands in the Galapagos to lose its tortoise population. Although the crew of the Essex had already done its part in diminishing the world's sperm-whale population, it was here on this tiny volcanic island that they contributed to the eradication of a species.
We didn't go to Isla Santa Maria on our trip. There are dive sites there, but it wasn't part of our itinerary. I would have liked to see what the island looks like today. On the map I bought at the Charles Darwin Research Station (ironically, about the closest we came to Isla Santa Maria), the islands are colored to show vegetation and such. Isla Santa Cruz is pretty much entirely a lush green. Isla Santa Maria is almost completely brown, with just a bit of green near the peak.

One of the reasons people visit the Galapagos is to see the islands where Charles Darwin explored and examined the variety of life and the environmental factors that shape it, contributing to his development of his theory of speciation. A mere fourteen years or so before Darwin's visit, a careless, reckless sailor almost single-handedly wiped out at least one subspecies (PDF) of that great variety. I've read estimates that whalers may have taken as many as 15,000 tortoises from this one island for food, not to mention those wiped out by the fire.

As I noted in my other Galapagos posts, the hand of man rests heavily on the islands. Nature has done amazing things there, but mankind seems determined to show that it, too, can shape the course of evolution and extinction.

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