Rocky Road: Ernst Haeckel

Ernst Haeckel

In a letter to her son in the 1870s, Emma Darwin, the great naturalist's wife, wrote that a recent guest was "very nice and hearty and affectionate, but he bellowed out his bad English in such a voice that he nearly deafened us." The guest was Ernst Haeckel.

From Wonderful Life by Stephen Jay Gould

From Art Forms in Nature by Ernst Haeckel

Born in 1834, Haeckel was both an early and an ardent proponent of Darwinism. He studied medicine at the universites of Würzburg and Berlin, but soon realized he hated disease too much to be a good doctor, observing, "I view anatomy purely from the viewpoint of the natural history of man — not a medical one!" When he opened a medical practice in Berlin, it was only a formality. He then embarked on a lengthy trip to Italy, financed by his father, where the young man toyed with the idea of becoming a landscape painter. By then, Dad had lost patience, and Haeckel abandoned that fancy and turned to science. Armed with a powerful microscope he had picked up in Florence and tiny marine organisms he had identified during his trip, he set out to make history in science. Later historians had to admit, however, that plenty of his science was speculative.

In 1868, Haeckel published History of Creation arguing that human evolution consisted of precisely 22 phases, the 21st — the "missing link" — being a halfway step between apes and humans. (The missing link was what the Dutchman Eugène Dubois, discoverer of Homo erectus, would later resolve to find.) Haeckel championed the notion of "ontogeny recapitulates phylogeny," in other words, the development of an individual shows the evolutionary history of its species. He compared embryos of various vertebrate species to support this argument, but grossly exaggerated the similarity of the embryos in their early stages. Even one of his contemporaries, Wilhelm His, accused him of distorting his images. The years have been kinder to the more retrained hypothesis of Karl Enrst von Baer, who simply argued that different species' embryos look more alike than do the adults.

Many of the ideas Haeckel promoted throughout his career have failed to endure 20th- and 21st-century scientific scrutiny. Far worse, many of his ideas were racist. A notable example is his supposition that humans comprised 12 distinct species, evolved from an ancestor who had lived on a now submerged continent he called Lemuria. Haeckel expected — and wasn't very upset by the idea — that the "superior" Germanic peoples would eventually drive out the "inferior" groups. He advocated strong governments encouraging racial competition and war. In the decades after his death, such extreme eugenic leanings had murderous consequences. It's hard to say what Haeckel actually would have thought had he seen the consequences of the Third Reich, and in all fairness, his sentiments were commonplace around the turn of the 20th century.

From Art Forms from the Ocean by Ernst Haeckel

In 1866, Haeckel published a set of genealogical trees showing the relationships of all known orders of organisms. These, like his theories on human evolution, have been criticized by later scientists. In his tree of vertebrate evolution, he downplayed seemingly unimportant organisms, such as fish, even though fish remain the most diverse of all vertebrates. He also portrayed patterns of evolution that don't necessarily occur, like increasing diversity over time. Yet this was the first outline of biology incorporating the principles of Darwinian evolution, and a major accomplishment. And Haeckel's speculations sometimes proved correct. The Cambrian Period, roughly 545 to 505 million years ago, marked a dramatic diversification of life forms found in the fossil record, yet the fossil record is pretty sparse before that time. In the 1870s, Haeckel asserted that Precambrian life forms had been tiny — roughly the same size as modern embryos. Modern finds of Precambrian fossils suggest that Haeckel was right.

One of Haeckel's earliest works was an atlas of radiolarians, published in 1862. Radiolarians are single-celled organisms whose lineage extends back to the Precambrian. Haeckel thought radiolarians were multi-cellular animals, and he misinterpreted their nuclei and the symbiotic algae that some of them carried. Nevertheless, he produced illustrations of the radiolarians that were both detailed and beautiful. It has been argued that what he "saw" was influenced by Jugendstil, the Art Nouveau form popular in Germany at the time. Whether or not artistic style influenced Haeckel's illustrations, his illustrations certainly influenced later art forms, including light fixtures, jewelry, furniture, and even a gateway to the Paris Word Fair in 1900. Later in his career, Haeckel produced Art Forms in Nature, a work that he published in a series of 10 installments. Designed to interest the general public in naturalism, they included Haeckel's own illustrations of animals, plants and microscopic organisms. In 1913, he published a set of photographs titled Nature as an Artist, aimed at countering accusations that his illustrations could be misleading. Today, however, many scientists and science historians share the conviction that his images were at best highly contrived, beautiful as they may be.

For more information:
Art Forms in Nature by Ernst Haeckel
Art Forms from the Ocean by Ernst Haeckel
Wonderful Life by Stephen Jay Gould
I Have Landed by Stephen Jay Gould
Evolution by Edward J. Larson
Human Origins: The Search for Our Beginnings by Herbert Thomas
"Painting the Whole Picture?" by Philip Ball in Nature Magazine, February 1, 2007 issue
Making Modern Science by Bowler and Morus
Java Man by Swisher, Curtis and Lewin
Evolution: The Triumph of an Idea by Carl Zimmer
Your Inner Fish by Neil Shubin
Evolution by Linda Gamlin
The Man Who Found the Missing Link by Pat Shipman
The Lying Stones of Marrakech by Stephen Jay Gould