Robert Broom and the “End of Evolution”

During my studies of the history of paleontology I have often stumbled upon the work of the same scientists over and over again. The 19th century anatomists Richard Owen and Thomas Henry Huxley, especially, worked on a variety of fossil vertebrates and were critical to the establishment of paleontology as an evolutionary science, yet there are other influential researchers who have not retained the same level of notoriety. The Scottish paleontologist Robert Broom, an immigrant to South Africa who belonged to the generation of scientists after Owen and Huxley, was among these lesser-known figures.

What Broom is best known for will depend on who you ask. A paleoanthropologist will tell you that Broom was one of the few scientists who believed that Raymond Dart’s 1925 discovery of Australopithecus africanus was important to understanding human origins. While Dart put his paleoanthropological research on hold after the discovery, Broom scoured the fossil deposits of South Africa to find mind fossil “ape-men.” A dinosaur specialist, however, might tell that Broom’s description of the archosaur Euparkeria appeared to throw support to the idea that both birds and dinosaurs had evolved from a group of bipedal, crocodile-like creatures that were called “thecodonts” at that time. (Though we now know that birds are only modified dinosaurs.) This work was related to Broom’s description of the Permian synapsids/stem mammals of the Karoo desert, and his efforts to establish the evolutionary proximity of these fossils to mammals were especially important.

Yet Broom should not be viewed only in the light of the number of fossils he found or genera he described. Broom had his own unique view of how evolution worked, and he shared these views most prominently in multiple works towards the end of his life. Succinctly put, in his last works Broom stated that evolution had halted for every species except humans, and he believed that evolution in the past had been driven by supernatural factors.

Like Richard Owen, Broom rejected both natural selection and Lamarckism as potential factors for evolutionary change. Instead he believed that the evolution of life occurred through a sequence fore-ordained by a Creator, and that once humans had evolved the transmutation of other species was halted for our benefit. Only our species could keep reaching up the evolutionary ladder set before us. While Broom couched this belief in the scientific-sounding claim that all living animal species were too-specialized to evolve any further, his peers could not accept his view of evolution as supernaturally-guided.

(This rejection is interesting given the popularity of the idea among paleontologists during Broom’s time that evolution might be driven by internal factors and even directed towards certain endpoints. Perhaps such ideas were not as offensive to researchers because they could be squared with theology without actually allowing a place for theology within scientific discourse.)

As historian Marc Swetlitz has pointed out, however, Broom’s books on this subject, like The Coming of Man: Was it Accident or Design?, had a significant influence on Julian Huxley. Huxley, grandson of T.H. Huxley and a popularizer of the “Modern Synthesis” of evolution that coalesced in the mid-20th century, had long espoused a belief in human progressive development. Huxley was tired of seeing humans go to war over competing economic and social ideals. If we took our cues from evolution, a natural phenomenon which had clearly made our species superior, then we could form a more peaceful and productive society.

This “progressive” view of life made Broom’s work instantly appeal to Huxley. Huxley could not accept some of Broom’s religious conclusions, but he used Broom’s work to support the idea that evolution had come to a halt in every species except our own. Broom’s work provided the scientific basis for what Huxley wanted to believe.

Ultimately, though, this aspect of Broom’s work only seems to be remembered by historians of science and modern creationists who wish to capitalize on Broom’s teleological vision of life’s history. Not only did Broom work during a time that is often overlooked by science popularizers (the public could be forgiven for thinking that paleontology/evolutionary science lay dormant between 1870 and the late 20th century), but he proposed a spiritually-infused version of evolution that was generally rejected by this colleagues. Like many scientists of decades past, Broom continues to be cited but his work is rarely fully understood.

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