Daily Archives: April 19, 2016


Honoring Darwin

Darwin Finches

Darwin with 4 of his 13 finch species

April 19 marks the 134th anniversary of Charles Darwin’s passing.  Darwin was not only the father of evolution, but also a giant in the advancement of science. Author of at least 20 books, Darwin was best known for one: On The Origin of Species.

Having read three books about Darwin, including one that he wrote, and having traveled recently to the Galapagos Islands with Naturalist Journeys, I am in greater awe of him now than I was before.

Imagine leaving your friends and family behind at age 26 for a three-year globe-trotting adventure in a ship filled with people, most of whom you did not know.  During the voyage on the Beagle, Darwin endured long bouts of sea sickness, various other ailments, threats of violence and profound loneliness. Darwin collected a tremendous number of specimens and took copious notes on species he found in at least a dozen countries on four continents. The journey lasted much longer than expected — five years!

One of the things Darwin postponed was his higher education at divinity school.  The man that religious conservatives have condemned for his theory of evolution for the last two centuries was training for a career in the church.  Darwin remained a committed Christian to the end of his life and denied that his theory of evolution was in conflict with the church.

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Galapagos Mockingbird

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Large Ground Finch

His theory of evolution was heavily influenced by the adaptations made over the years by Mockingbirds and Finches on the Galapagos archipelago.  The key to the finch’s survival was their beak.  He noticed that they came from a common ancestor (as did the mockingbirds), then through adaptive radiation developed specialized beaks to maximize food and survival opportunities on the islands.  This allowed them to adapt to conditions on different islands.  As we discovered on our recent trip to the Galapagos, the islands often have great distances between them, up to 100 miles, with a wide variety of habitats ranging from bare volcanic basalt to scrub desert and Palo Santos forests.

Iquana crabs

Marine Iguana with Sally Lightfoot Crabs

Evidence of evolution was and still is everywhere on the Galapagos. Darwin referred to the islands as a “living laboratory of evolution.” In addition to noticing the variations in beaks of the finches, he noticed different species of Mockingbirds living on different islands, variations in giant tortoise shells from island to island, iguanas that could swim (Marine Iguanas), and the world’s only flightless cormorant.

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Galapagos Flightless Cormorant

Twenty-four years after his epic voyage, he submitted a paper together with Alfred Wallace to the Linnaean Society of London.  Wallace conducted his field studies in the Amazon River Basin and in Malaysia, Singapore and the island of New Guinea.  The two great naturalists independently arrived at the same theory at about the same time.  Natural selection was the mechanism for evolution they both discovered via their field work and analyses of species in different parts of the world.

In 1859 Darwin published the Origin of the Species.  The central idea was in fact simple: organisms change over time to adapt to their surroundings.

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Giant Galapagos Tortoise

Darwin and Wallace’s discovery not only revolutionized our thinking in general, but it also showcased the power of science.  As Eric Weiner said in his brilliant book The Beak of the Finch “Science formalizes our special kind of collective memory, or species memory, in which each generation builds on what has been learned by those that came before, following in each other’s footsteps, standing on each other’s shoulders.  Each generation values what it can learn from the one before, and prizes the discoveries it will pass on to the next…”  Thanks to Darwin and Wallace, science and medicine in particular have made tremendous advances.

Finally, there is a very human context for Darwin’s discoveries.  Adaptations are not only apparent in Galapagos wildlife, they are apparent in humans.  In Weiner’s words “Our minds and talents are variable for the same evolutionary reason as finch’s beaks are variable in the Galapagos:  jack-of-all trades master of none.  And what drives this radiation within our species is a process like character divergence.  Though we may not think of it as Darwinian, we all feel its pressure, wanting and needing to do what we are made for – seeking the task for which we are most fit.”

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Darwin arch & monument, Puerto Ayora

Darwin’s extensive field work, studies, specimens and writings have formed the basis for biological understanding ever since. We should all be grateful for the man’s intelligence, dedication and courage.

 

Sources:  The Voyage of the Beagle by Charles Darwin; Beak of the Finch by Eric Weiner; The Origin by Irving Stone