Book Review: Darwin’s Other Theory
By Vicki Linton
Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral by David Dobbs has an unlikely subject for a book marketed to a general audience. More than anything it is about Alexander Agassiz. It caught my attention for that reason, as there are no modern biographies of the son of Louis Agassiz. But if it might be wondered who would care about Louis Agassiz, it’s vastly more doubtful that anyone other than an academic specialist would be interested in Alexander Agassiz. (Why I am interested is another post!)
The book bases its claim for a larger audience on the inclusion of Charles Darwin in its title. And for reasons I will get to, Darwin’s is the most interesting story in the book.
Dobbs explores the conflict between Darwin and Agassiz by following much of the life of Alexander. The conflict was one of ideas; the topic at issue was how coral reefs are formed. Beneath the subject of coral reefs, Dobbs sees a contrast in scientific method between Darwin and the younger Agassiz.
Dobbs’ hypothesis is that Alexander was motivated to find fault with Darwin’s coral reef theory because it was Darwin’s theory of evolution which buried his father Louis’s theories of creationism, leaving the older Agassiz behind as science progressed in the 19th Century.
Most of Alexander Agassiz’s quest to overturn Darwin’s theory of coral reefs occurred after Darwin had died. Agassiz did accept Darwinism and it is not clear from Dobbs’ telling that Alexander’s motivation was to avenge his father.
Dobbs presents the conflict between Darwin and Agassiz as fundamentally about how to do science. In pursuing science, Darwin thought large, using imagination to create an explanation and then searching the evidence to see if the hypothesis would fit the facts.
Against his bold approach, Agassiz was a cautious collector of facts, loathe to build encompassing theories until he had seen for himself enough evidence that he felt he could move toward a comprehensive explanation.
Alexander Agassiz lived out this approach as he tackled the question of how coral reefs formed. He sailed to nearly all the South Pacific islands rimmed by coral reefs and spent days measuring atolls and their surrounding waters, visiting many more islands than Darwin ever did. Darwin, Dobbs says, did most of his thinking about coral reefs in his Down House study, pouring over charts drawn by others.
In fact, as Darwin biographer Janet Browne tells it, Darwin conjured up his theory of coral reef formation six months before he ever saw a coral reef. The theory did not come without observation, however. Darwin was observing and studying geological processes along the South American coast when, during an excursion high into the Andes, he hit upon an explanation for coral reef formation.
Months later Darwin had a brief glimpse of coral reefs in Tahiti. His only close observation came when the Beagle stopped at the Keeling Island atoll while crossing the Indian Ocean on the way home to England. He never saw another reef after that.
Agassiz did not believe a short visit and book study were enough to understand coral reefs. He chartered ships for several months-long trips to the South Pacific and the Indian Ocean to gather the evidence he felt was needed.
Yet all his voyaging and careful observation led to failure. Ultimately science showed that Charles Darwin’s coral reef theory was correct.
And that is the most interesting story of Reef Madness. Darwin briefly visited a few reefs on his Beagle voyage. After he returned home he pondered what he saw and the theory that had come to him in the Andes. Years before he published his theory of evolution, he published this explanation of coral reefs.
Long into the 20th century, the scientific arguments about coral reefs continued. Darwin’s theory maintained adherents but many scientists proposed other ideas. The technology to definitively determine what the correct answer was did not exist.
Until the 1950s. Then scientists were able to drill deep enough into coral reefs to determine that long before, in an era without advanced technology, Darwin had thought up the correct explanation.
Alexander Agassiz was a good and careful scientist. His published work included a massive study classifying the world’s echinoderms (e.g. starfish) that still has value today. But his was not a mind of daring and creative imagination and he was not able to contribute to science at the level of Charles Darwin. And so, like his father Louis, he too has been left behind by science.
Ironically, Louis Agassiz was a big thinker. He intended his creationist ideas to explain all of life. He imagined the evidence fit his views, but it did not. Alexander Agassiz’s caution may have derived from watching Louis’s boldness crumble to nothing. But then when Alexander pursued his careful science, his ideas too were defeated by a big thinker—the same Charles Darwin whose theory had invalidated his father’s.
Oh and if you want to know how coral reefs are formed? You’ll have to read the book.