Rocky Road: Louis Agassiz

Louis Agassiz

In 1834, in the midst of a terse debate over the nature of sedimentary strata in England, the eminent geologist Roderick Impey Murchison realized he needed some reliable identifications of fossil fish, as well as some stellar support. He turned to an accomplished young scientist and recent winner of the Geological Society of London's prestigious Wollaston medal: Louis Agassiz. Charming as well as talented, Agassiz had persuaded the great Georges Cuvier to entrust him with the task of describing the world's fossil fishes, in Les Poissons Fossiles. This single monograph, completed between 1833 and 1843, increased more than tenfold all formally described vertebrates known to science.

From Finders, Keepers by Rosamond Wolff Purcell and Stephen Jay Gould

Besides Cuvier, Agassiz credited his success to the support of his long-time artist-collaborator Joseph Dinkel, who drew most of the plates in Les Poissons Fossiles. But this illustration, of a fish submitted for description by August Goldfuss, was done by Goldfuss's collaborator Christian Hohe, and named for Agassiz's personal friend but professional adversary Charles Lyell.

Despite their differences on other issues, Agassiz and Lyell both put their support behind a revolutionary new theory: the Ice Age (in the Pleistocene). Originally a disbeliever, Agassiz found himself persuaded by Ignace Venetz and Jean de Charpentier that Switzerland had once been buried under a great glacier; he eventually became the indispensible popularizer of their ideas. Later discussions with his old school buddy Karl Schimper fueled his much more extensive and controversial Ice Age theory. (The two would later have a bitter falling out over who truly deserved credit for the idea.) In 1837, Agassiz presented the theory at a meeting of the Swiss Society of Natural Sciences, but the scientific community was not yet ready for the idea, and it would take years before fellow geologists were persuaded. In fact, Agassiz figured out the correct picture, but based on the wrong assumption: He was convinced that the Ice Age had extinguished all life on the planet to prepare it for its present flora and fauna, especially people.

Just a few years after publication of Les Poissons Fossiles and his presentation of the Ice Age theory, financial ruin and a failed first marriage drove Agassiz to the other side of the Atlantic. This move marked a turning point in his life; he never again achieved the same level of innovation and discovery. In his later years, he became best known for his staunch opposition to Darwinian evolution. So vehement was his resistance to any discussion of the subject that his students — partly as a joke, partly motivated by irritation over other matters — formed an organization named the "Society for the Protection of American Students from Foreign Professors." When Agassiz learned of the club, he forced the students to leave. Agassiz was especially irritated when his own findings were interpreted as evidence of evolution. He described what he called "three-fold parallelism" — the relationship between comparative anatomy, embryology and geology. Ernst Haeckel cited it as "one of the strongest proofs of the truth of the theory of evolution." Agassiz was nearly apopleptic.

Still certain that the Ice Age had wiped out all life, Agassiz journeyed to the equator looking for evidence of glaciers. The only "evidence" he found was silt. (In fact, glacial deposits have been found in equatorial regions, but from much earlier geologic periods than the Pleistocene.)

In his later years, however, Agassiz still contributed to science in significant ways. He founded the Museum of Comparative Zoology at Harvard. He helped persuade Abraham Lincoln to form the National Academy of Sciences. And his second wife founded Radcliffe College. Agassiz's son, Alexander, was also a prominent scientist. Unlike his father, Alexander quietly accepted Darwin's theory of evolution, though he devoted himself (unsuccessfully) to challenging Darwin's theory of coral atoll formation.

For more information:
The Ice Finders by Edmund Blair Bolles
Finders, Keepers by Rosamond Wolff Purcell and Stephen Jay Gould
The Meaning of Fossils by Martin J.S. Rudwick
To See the Fellows Fight by John C. Thackray
The Great Naturalists edited by Robert Huxley
The Great Devonian Controversy by Martin J.S. Rudwick
Charles Darwin, Geologist by Sandra Herbert
Cultures of Natural History edited by Jardine, Secord and Spary
The Dragon Seekers by Christopher McGowan
Evolution's Workshop by Edward J. Larson
The Rarest of the Rare by Pick and Sloan
Evolution by Linda Gamlin