Born in Africa_ The Quest for the Origins of Human Life - Martin Meredith [11]
Dart’s article was published in Nature on 7 February, and one week later Nature published the comments of the four eminent experts it had solicited. All four emphasised the difficulty of assessing a fossil, especially a juvenile fossil, from a preliminary report and a few photographs. But they all nevertheless detected more similarities with apes than humans.
Keith’s opinion, in particular, carried enormous weight. He was a central figure in an international circle of distinguished scientists, holding high office in several scientific organisations. His initial response was guarded:
It may be that Australopithecus does turn out to be ‘intermediate between living anthropoids and man’, but on the evidence now produced one is inclined to place Australopithecus in the same group or sub-family as the chimpanzee and gorilla. It is an allied genus. It seems to be near akin to both.
Elliot Smith was more sceptical. During Dart’s tenure at University College, he had acted as his mentor and had been instrumental in persuading him to take up the post in Johannesburg. But now he was worried about the extent of Dart’s claims. ‘Many of the features cited by Professor Dart as evidence of human affinities, especially the features of the jaw and teeth mentioned by him, are not unknown in the young of the giant anthropoids and even in the adult’. And he asked for more proof. ‘What above all we want Professor Dart to tell us is the geological evidence of age, the exact condition under which the fossil was found, and the exact form of the teeth’.
Smith Woodward was dismissive. ‘I see nothing in the orbits, nasal bones, and canine teeth definitely nearer to the human condition than the corresponding parts of the skull of a modern young chimpanzee’. He challenged Dart’s assertion about an African origin for humankind. ‘The new fossil from Africa certainly has little bearing on the question’. And he concluded by regretting that Dart had chosen to use a ‘barbarous’ combination of Latin and Greek in naming the specimen Australopithecus.
Duckworth was more sympathetic. It was illustrations from Duckworth’s treatise Morphology and Anthropology that Dart had used to make a comparison between the Taung specimen and apes. But he raised the question of whether the apparent humanlike features were not due to the young age of the specimen and concluded that the Taung child was most closely related to a gorilla.
In answering this barrage of criticism, Dart was severely hampered by the circumstances surrounding the discovery of the Taung child’s skull. At the time the skull was picked up in the quarry, no attempt had been made to measure, photograph or accurately record the site’s stratigraphy in a way that would have helped establish how old the specimen was. The all-important question of the age of the skull thus remained unresolved. Nor was Dart able to overcome the difficulty of proving that the ‘humanoid’ features to which he had pointed were not due to its childlike age; no adult specimen was available.
But the most formidable hurdle he faced was how to overcome objections about the size of its brain. Keith calculated that the infant Australopithecus possessed a brain capacity of less than 450 cubic centimetres; and that the brain capacity of an adult of its kind would reach no more than 520 cubic centimetres. It was thus hardly a suitable candidate for being in the direct line of human ancestors.
Worse was to follow. The experts had based their opinions entirely on Dart’s description and illustrations. They were keen to see, if not the original specimen, then at least a cast (replica) of it. But Dart was slow to produce casts. No one in his department knew how to make them; nor did he. Eventually he hired a professional plasterer for the job.
But instead of giving the experts a preview of the casts, Dart sent them as exhibits to the South African pavilion at the British Empire Exhibition at Wembley