In the fall of 1924, Raymond Dart made an astonishing discovery: the skull of a juvenile australopithecine, nicknamed the Taung Child. Dart had found a human ancestor, but the scientific community wasn't yet ready for such an apelike relative. Alternately dismissed and ridiculed, Dart took the reaction personally. In the more than 20 years that passed between his published description of Australopithecus africanus and its acceptance, he largely withdrew from anthropology, leaving the defense of the fossil child to an exuberant associate, Robert Broom. But as far as winning over the scientific community was concerned, Broom was a mixed blessing.
Robert Broom was born in Scotland in 1866 to a family of limited means. Growing up poor, he developed a dislike for the wealthy elite, and the resentment a poor boy can feel for the rich translated into a lifelong distrust of established authority. Challenging such authority became his lifelong vocation.
In his twenties, Broom followed his brother to Australia, drawn partly by the chance to study marsupials and monotremes, but he didn't linger there for very long. A look at some fossils dug up from South Africa's Karoo region convinced Broom to head for Cape Town, his patient wife in tow. Without an invitation or significant funding, however, he gave up on his first attempt to settle in South Africa, and he and his wife retreated to Britain. A few months later, however, they were back. An obstetrician, Broom set up medical practices in towns near the fossil localities he wanted to study. In 1903, he finally obtained a professorial post at Victoria College, studying zoology and geology. A couple years later, he was named honorary curator at the South African Museum. It turned out to be the start of a stormy relationship. Broom was briefly accommodated by a free rail pass to enable him to move around the country digging and describing fossils (he was often short of cash), but when the rail pass was revoked by a new railroad minister, Broom blamed the museum. He cultivated other working relationships, and eventually came under fire for selling South African fossils to foreign institutions. By the early 1920s, was barred from studying the museum's collections, and kicked out of the South African Association for the Advancement of Science.
In the mid-1920s, Dart's Taung Child discovery riveted Broom, who dropped in on Dart unannounced, reportedly dropped to his knees in adoration of the Taung Child, and then shifted the focus of his own research from fossil mammals to paleoanthropology. Broom's influence in the field was limited, but he realized that the Taung Child's status as a juvenile hampered its acceptance by the science community (juvenile apes look much more humanlike than adult apes) and that adults were needed.
Before South Africa was known for hominids, it was known for gold, and lime is useful in gold processing, so European settlers mined the limestone caves west of Johannesburg and Pretoria — with explosives — for many years. In 1936, Broom approached G.W. Barlow, the quarry supervisor at the Sterkfontein Caves. Barlow had worked at the quarry at Taung years earlier, so when Broom asked for fossils like the Taung Child, Barlow knew what he meant. Within days, Barlow gave Broom a fossil cast of a braincase. More digging found an associated skull, though a badly mangled one. But it was enough for Broom to declare it the type specimen of a new species: Plesianthropus transvaalensis. In 1947, Broom and his assistant John T. Robinson discovered another australopithecine fossil, this one in much better shape. Broom nicknamed this fossil Mrs. Ples. Both the type specimen and Mrs. Ples, whose gender is still a matter of debate, have been reclassified as Australopithecus africanus, and Mrs. Ples is estimated at 2.5 million years old.
Paleontologists of all stripes face challenges in describing fossil species. If two individuals show considerable differences, is that just variation within one species, or two different species? Scientists who err on the side of grouping individuals together are called lumpers. Scientists who err in the opposite direction are called splitters, and Broom was known to be a notorious hominid splitter. Another of his arguments, which has better withstood the test of time, is that australopithecines came in two basic types: robust and gracile, and both walked upright. He found the remains of both types, and he defined the robust australopithecine Paranthropus robustus in 1938.
Broom excelled at finding fossils, due perhaps partly to his boundless energy. In his seventies, he could scramble up slippery fossil-laded slopes faster than people half his age. His success might have also been due to something else, something borrowed from miners: dynamite. He blasted overburden away from precious fossils — a practice that cracked Mrs. Ples's skull and hampered attaching accurate dates or contexts to multiple fossils. Broom argued that the rock was so hard, he really had no other choice. After the dust settled, Broom would appear crawling over the quarry looking for bones, wearing his trademark black suit.
Given his support of Dart's find of a human ancestor in Africa, one might expect Broom to be a Darwinian, but he was not. Natural selection struck Broom as insufficient to account for the diversity of life on Earth. Random mutations taken advantage of by natural selection could not, in his view, explain the jewel-toned feathers of hummingbirds, much less the genius of Shakespeare.
Broom could be called an intelligent design advocate, though his candor might make even the Discovery Institute blush. He proposed that the variety of life could be explained more plausibly by "spiritual agencies." Unlike today's IDers, Broom believed not in one intelligent designer, but in a multitude of designers with different priorities. For instance, the designer of drab raptors was perhaps driven by a Nordic-like interest in ruthless efficiency, while the designer of the pretty peacock would have made an excellent shopping companion for someone on a generous budget. Broom elaborated his views on the actions of spiritual agencies in his 1933 book The Coming of Man: Was it Accident or Design?
Broom knew the scientific community didn't agree with him. He didn't care. In fact, he wasn't the only one to question the power of natural selection at the time; Darwin's theory actually experienced varying levels of acceptance in the decades following The Origin of Species. The neo darwinian synthesis, which would ultimately incorporate elements of natural selection, genetics, mutation, population biology and paleontology, hadn't quite come to fruition when Broom published his manifesto.
Besides his belief in spiritual agencies, Broom clung to a few other notions not uncommon for the time. One was a suspicion that specialized organisms have a harder time adapting to new circumstances, and that most life on Earth was highly specialized and couldn't evolve any more. Another was the belief that human intelligence only reached its full flower in temperate zones; in the tropics, good men degenerated — a typical racial stereotype from the early 20th century. Yet another belief was that modern man was the ultimate aim of all evolution (apparently the spiritual agencies could all agree on that). Having achieved mankind, evolution had come to an end on our planet.
Just as he believed that evolution could simply stop once it had reached its goal, Broom reputedly felt the same way about his own life. Having finished a monograph on hominids in 1951, he was said to write, "Now that's finished . . . and so am I." He died later that evening.
Narrative text and graphic design © by Michon Scott - Updated June 18, 2019