Ernst Haeckel and his recapitulation theory
When approaching Haeckel (1834–1919), you discover that he was complicated – and maybe this is the reason for his attractiveness. This is not only so for his controversial theory of recapitulation, a very tricky subject, whose claim that ‘ontogeny recapitulates phylogeny’ is tough by itself, but for the interaction of a wide range of interests and their evolution during his life. His vigorous human nature emerges, for better or worse, beyond his results and great mistakes, and delineates the profile of an 18th-century-like scientist (I think that he was out of step with his time), artist, natural philosopher and traveller – the latter also in romantic terms. He was undoubtedly a smart person, with rare comprehension skills and a terrific ability to analyse and summarise. He was the first person known to use the terms ‘First World War’, ‘Darwinism’ and ‘ecology’, for example, and to postulate a ‘missing link’ between ape and man (which was proven correct when Java Man was found in 1891), an indubitable sign of his proactive understanding.
Ernst Haeckel was born in Potsdam, Prussia back then. He studied medicine and science at the University of Berlin, and was professor of zoology at Jena until his retirement. However, he spent his life not only in the campuses and laboratories of the universities, but mainly travelling far and wide, from the North Sea to Sicily, to Ceylon and beyond. Always carrying his microscope, sketchpads and watercolours. His idol was Goethe and his light Charles Darwin.
Darwin’s The Origin of Species, which had been translated into German in 1860, represented a sort of revelation to him. His enthusiasm for the theory of evolution grew so much that he created evidence to support his beliefs, in a very naïve (and fraudulent too) way. To explain the gap between inorganic non-living matter and the first spark of life, he invented for example minute protoplasmic organisms called Monera, ‘not composed of any organs at all, but consist entirely of shapeless, simple homogeneous matter … nothing more than a shapeless, mobile, little lump of mucus or slime, consisting of an albuminous combination of carbon.’ (“The Imaginary Monera” – Russell Grigg).
In his book Natürliche Schöpfungs-geschichte, published in German in 1868 and in English in 1876 with the title The History of Creation, Haeckel proposed the idea that humans developed as embryos through stages in which they were identical to other main types of animals in the same stages. Thus, he claimed that an individual organism’s biological development, or ontogeny, parallels and summarises its species’ evolutionary development, or phylogeny. Especially the Church fought this controversial and discredited ‘law of recapitulation’. However, Haeckel’s aim wasn’t to consider the human foetus as a fish (this was the argument widely used by abortionists), but to show the evidence of evolution and to understand the connection between phylogeny and ontogeny, in which he strongly trusted. He used several illustrations prepared by his own teacher, Albert von Kölliker, whose goal was to explain human development while also showing other mammalian embryos to demonstrate a coherent process. It seems that Haeckel changed these illustrations purposely to support his theory, and, according to the vehemence of his character, this hypothesis is utterly reasonable. Rumour had that Haeckel was charged with fraud by several professors and convicted by an academic court, but there isn’t evidence of this part of the story. Robert Richards, an author and professor of the History of Science and Medicine at the University of Chicago, in a paper published in 2008, defended Haeckel’s work and stated that some of the criticisms of embryo drawings were legitimate, while others were unfounded. In any case, even though the drawings have been considered often inaccurate or fake, they show still an interesting comparison and are used for evidence for evolution.
Now, it is clear that there is not a one-to-one correspondence between ontogeny and phylogeny, or rather the idea is now known to be completely false. However, we have to understand the time in which Haeckel lived, the problems of research, the tools available, and especially the strong resistances to Darwin’s theory – of which he was a sort of German prophet.
Later, Haeckel launched a scientific discipline, the ecology, dedicated to studying the interaction between organism and environment (his book The Riddle of the Universe became a bestseller), and developed a philosophy called ‘monism’. The German Monist League, which combined ecological holism with social views, became soon a manifesto for nationalism and racism and was one of the main seeds for National Socialism.
Thus, it seems that both Haeckel’s illuminations about evolution and ecology – through his recapitulation theory and his philosophy of nature – had had divergent and unintentional results, becoming the flags for abortionists (“The infamous fish stage in Human Embryos” – Russell Grigg) and Nazis (“Haeckel and the Rise of Nazism” – Russell Grigg again).
Just to underline how much Ernst Haeckel is a controversial character, we must not forget that he was a masterly artist, able to influence many art forms, including light fixtures, furniture, jewellery and architecture too. I have said that his idol was Goethe, for whom morphology had aesthetic roots. Haeckel’s on-the-spot drawings of vegetation, animals and creatures were turned into more than 1000 engravings and then transformed into coloured lithographs that are still considered to be one of the marvels of 19th-century naturalist drawings. If you Google his images, you certainly recognise many forms that characterised the Art Nouveau movement.
In conclusion, Haeckel’s legacy lies in art more than in science, where artistic exuberance and naivety is not tolerated anymore.