Human Origins and Evolution: From Ardi to Lucy to Us

Darwinian scholars accessed a mostly European paleontological record of human evolution from primarily archaeological contexts. Huxley's lectures on man's place in nature--and Lyell's book on the antiquity of man--were already 45 years old when the Paleontological Society was founded in 1908. Eighteenth-century, post-Darwinian breakthroughs in hominid paleontology involved the unveiling and differentiation of neanderthals as regular occupants of Pleistocene Europe via discoveries such as Cro-Magnon in France (1868), Spy in Belgium (1886), and Krapina in Croatia (1899-1905). An earlier and more primitive hominid was found on Java by Dubois in 1891. By the time of the Society's founding, debates about the place of neanderthals and most ancient Homo had already been formulated by scholars like Schwalbe and Keith. The neanderthal debate has only recently subsided in the face of consilient breakthroughs in the paleontological and neontological (biomolecular) realms.

The last century of hominid paleontology has seen the veil lift progressively from younger to older. The illumination of early hominid diversity and phylogenetic relationships began with Dart's breakthrough discovery of South Africa's Taung child in 1924, but decades passed before Australopithecus was afforded hominid status. Breakthrough discoveries at Kromdraii (1938) and Olduvai Gorge (1959) established beyond doubt the presence of a robust hominid clade. Even older fossils from Hadar and Laetoli (1970s) then revealed very primitive Australopithecus. The four-million-year horizon was broken during the 1990s to reveal the presence of Ardipithecus. Today hominid paleobiology is probing at the roots and branches of the clade with a wide assortment of tools ranging from DNA sequencers to micro-CT scanners, but the next major breakthroughs will continue to be based on fieldwork, the discipline's bedrock.