Missing Link: The adventures with the "Mirror Link"
The anatomist Raymond Dart saw the "child of Taung" as the missing link in the history of human development. But at first it was met with criticism.
The skull of the child of Taung.
(Image: Cicero Moraes (CC BY-SA 4.0))
100 years ago, the anatomist and palaeoanthropologist Raymond Dart examined a bone find from a Northern Lime Company quarry in Taung, Betschuanaland. It took the specialist from the University of Witswatersrand 73 days to uncover the skull. His first description of the "child of Taung" in the journal Nature in February 1925 hit like a bombshell among experts, as Dart recognized a missing link in the evolutionary history of humans in what he called "Australopithecus africanus". It would be 25 years before the researcher's assessment was generally shared.
Palaeontology is a game, wrote the palaeoanthropologist Yves Coppens in his work on the roots of man: "This game, which consists of linking the different species of one and the same genus, the genera of one and the same family or the families of one and the same order, is played by as many participants as there are specialists in the world. [...] The solutions provided are published so that the other players always know how the game stands. The reviews and new models are then published in turn, and the game continues indefinitely. There are only temporary winners, as every family tree is constantly called into question, all the more so because it is the human family tree."
Critical reactions
Raymond Dart did not have a good hand in the game at first. He estimated that the skull he examined was that of a six-year-old child who had lived around three million years ago and was able to walk upright and orient himself spatially in the savannah. He interpreted other finds from the quarry as tools, thus classifying Australopithecus africanus as a man-ape rather than an ape-man. He called the classification as a family Homo-simiadæ, ascribed to the hominids. Dart had sent his conclusions (PDF) to the journal Nature in early 1925, but the journal initially withheld them and only published them on February 5, 1925, accompanied by comments from influential paleoanthropologists. They were all negative, in stark contrast to the preliminary report that appeared in the Johannesburg newspaper Star and announced a sensation.
Two anatomists complained that it was difficult to determine the human-like condition of a young child and referred to young chimpanzees and gorillas. A paleoanthropologist spoke out against the bone find because Dart had not examined the geological conditions at the site himself and had left this to a geologist from Johannesburg.
Dart's colleagues made fun of the pebbles found, which according to Dart were used as tools by Africanus and derided them as "Dartefacts". They also rejected Dart's explanation that pre-humans had to evolve on the barren South African savannah (the veldt), while the chimpanzees and gorillas found sufficient food in the forests. The Out-of-Africa theory, as previously suggested by Charles Darwin, was considered completely outdated at the time. Many of the players were still under the impression of the "Eoanthropus dawasoni", which was found in England in 1913. This bone find, also known as "Piltdown Man", consisted of a medieval skull with the lower jaw of an orangutan. The clever forgery, which was only discovered in 1953, was seen as proof that the cradle of mankind was on the British Isles. Contemporaries were particularly impressed by the size of this pre-human derived from the skull.
For Australopithecus africanus, on the other hand, Raymond Dart assumed a height of 1.25 meters and a weight of 25 to 30 kilograms. Early man was small and weak. Other researchers were influenced by Ernst Haeckel's "natural creation story". He assumed that the cradle of mankind was in South-East Asia in the vicinity of the habitats of orangutans and gibbons. Finds of "Java Man" from 1891 supported this theory.
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"Adventures with the Mirror Link"
Figure 2 in this article shows which bone finds were known and classified in 1925 and compares them with the current state of research. You can see how far-sighted Raymond Dart was in his "Adventure with the Mirror Link" (the title of his 1959 autobiography) when he classified his find as early man. The change in doctrine began with the discovery of further fossils in Africa that could be classified as belonging to the Australopithecus family. The anatomist Wilfrid Le Gros Clark, who examined the "child of Taung" himself in 1946 and confirmed the hominid relationship, was particularly influential. With the discovery of the skeleton of "Lucy" in 1974 and three and a half million year old footprints in Tanzania between 1976 and 1978, the Out-of-Africa theory was finally generally accepted and the Taung child finally became the find of the century.
But what is definitive? The game of palaeontology that Yves Coppens, the co-discoverer of "Lucy", wrote about, continues. Many a missing link is waiting to be found, some players are waiting for their luck, others are not. A few weeks ago, the case of an archaeologist from the Palatinate region of Germany who did not take the dating of his finds very seriously became known. He caused a stir back in 2017 when he found teeth in Eppelsheim near Worms. According to him, they were the missing link par excellence and proved that the development of modern humans did not begin in Africa, but in Rhineland-Palatinate! However, according to the rules of the game, he did not publish this result in an international specialist magazine, but in a Mainz newspaper.
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