Discovery of human antiquity
The discovery of human antiquity was a major achievement of science in the middle of the 19th century, and the foundation of scientific paleoanthropology. The antiquity of man, human antiquity, or in simpler language the age of the human race, are names given to the series of scientific debates it involved, which with modifications continue in the 21st century. These debates have clarified and given scientific evidence, from a number of disciplines, towards solving the basic question of dating the first human being.
Controversy was very active in this area in parts of the 19th century, with some dormant periods also. A key date was the 1859 re-evaluation of archaeological evidence that had been published 12 years earlier by Boucher de Perthes. It was then widely accepted, as validating the suggestion that man was much older than had previously been believed, for example than the 6,000 years implied by some traditional chronologies.
In 1863 T. H. Huxley argued that man was an evolved species; and in 1864 Alfred Russel Wallace combined natural selection with the issue of antiquity. The arguments from science for what was then called the "great antiquity of man" became convincing to most scientists, over the following decade. The separate debate on the antiquity of man had in effect merged into the larger one on evolution, being simply a chronological aspect. It has not ended as a discussion, however, since the current science of human antiquity is still in flux.
Contemporary formulations
Modern science has no single answer to the question of how old humanity is. What the question now means indeed depends on choosing genus or species in the required answer. It is thought that the genus of man has been around for ten times as long as our species. Currently, fresh examples of species of the genus Homo are still being discovered, so that definitive answers are not available. The consensus view is that human beings are one species, the only existing species of the genus. With the rejection of polygenism for human origins, it is asserted that this species had a definite and single origin in the past. The hypothesis of recent African origin of modern humans is now widely accepted, and states that anatomically modern humans had a single origin, in Africa.The genus Homo is now estimated to be about 2.3 to 2.4 million years old, with the appearance of H. habilis; meaning that the existence of all types of humans has been within the Quaternary.
File:Spreading homo sapiens la.svg|thumb|left|The spread of Homo sapiens, from the red area, over the last 100,000 years, represented with geographical areas for Neanderthals and early hominids. H. sapiens replaced other species of the genus Homo, over a long period of time.
Once the question is reformulated as dating the transition of the evolution of H. sapiens from a precursor species, the issue can be refined into two further questions. These are: the analysis and dating of the evolution of Archaic Homo sapiens, and of the evolution from "archaic" forms of the species H. sapiens sapiens. The second question is given an answer in two parts: anatomically modern humans are thought to be about 300,000 years old, with behavioral modernity dating back to 40,000 or 50,000 years ago. The first question is still subject to debates on its definition.
Historical debates
Discovering the age of the first human is one facet of anthropogeny, the study of human origins, and a term dated by the Oxford English Dictionary to 1839 and the Medical Dictionary of Robert Hooper. Given the history of evolutionary thought, and the history of paleontology, the question of the antiquity of man became quite natural to ask at around this period. It was by no means a new question, but it was being asked in a new context of knowledge, particularly in comparative anatomy and palaeontology. The development of relative dating as a principled method allowed deductions of chronology relative to events tied to fossils and strata. This meant, though, that the issue of the antiquity of man was not separable from other debates of the period, on geology and foundations of scientific archaeology.The first strong scientific arguments for the antiquity of man as very different from accepted biblical chronology were certainly also strongly controverted. Those who found the conclusion unacceptable could be expected to examine the whole train of reasoning for weak points. This can be seen, for example, in the Systematic Theology of Charles Hodge.
For a period, once the scale of geological time had become clear in the 19th century, the "antiquity of man" stood for a theory opposed to the "modern origin of man", for which arguments of other kinds were put forward. The choice was logically independent of monogenism versus polygenism; but monogenism with the modern origin implied time scales on the basis of the geographical spread, physical differences and cultural diversity of humans. The choice was also logically independent of the notion of transmutation of species, but that was considered to be a slow process.
William Benjamin Carpenter wrote in 1872 of a fixed conviction of the "modern origin" as the only reason for resisting the human creation of flint implements. Henry Williamson Haynes writing in 1880 could call the antiquity of man "an established fact".
Theological debates
The Biblical account included- the story of the Garden of Eden and the descent of humans from a single couple;
- the story of the universal biblical Flood, after which all humans descended from Noah and his wife, and all animals from those saved in the Ark;
- genealogies providing in theory a way of dating events in the Old Testament.
Human origins and the "universal deluge" debated
The Flood could explain extinctions of species at that date, on the hypothesis that the Ark had not contained all species of animal. A Flood that was not universal, on the other hand, had implications for the biblical theory of races and Noah's sons. The theory of catastrophism, which was as much secular as theological in attitude, could be used in analogous ways.File:Arche Noé Vaisseau Eglise.jpg|thumb|Noah's Ark, a stained glass window of the earlier 17th century, Church of Saint-Étienne-du-Mont, in Paris.
There was interest in matters arising from modification of the biblical narrative, therefore, and it was fuelled by the new knowledge of the world in early modern Europe, and then by the growth of the sciences. One hypothesis was of people not descended from Adam. This hypothesis of polygenism implied nothing on the antiquity of man, but the issue was implicated in counter-arguments, for monogenism.
La Peyrère and the completeness of the Biblical account
appealed in formulating his Preadamite theory of polygenism to Jewish tradition; it was intended to be compatible with the biblical creation of man. It was rejected by many contemporary theologians. This idea of humans before Adam had been current in earlier Christian scholars and those of unorthodox and heretical beliefs; La Peyrère's significance was his synthesis of the dissent. Influentially, he revived the classical idea of Marcus Terentius Varro, preserved in Censorinus, of a three-fold division of historical time into "uncertain", "mythical", and "historical".Debate on race
The biblical narrative had implications for ethnology, and had its defenders, as well as those who felt it made significant omissions. Matthew Hale wrote his Primitive Origination of Mankind against La Peyrère, it has been suggested, in order to defend the propositions of a young human race and universal Flood, and the Native Americans as descended from Noah. Anthony John Maas writing in the 1913 Catholic Encyclopedia commented that pro-slavery sentiment indirectly supported the Preadamite theories of the middle of the 19th century. The antiquity of man found support in the opposed theories of monogenism of this time that justified abolitionism by discrediting scientific racism.Already in the 18th century polygenism was applied as a theory of race. A variant racist Preadamism was introduced, in particular by Reginald Stuart Poole and Dominic M'Causland. They followed the views of Samuel George Morton, Josiah C. Nott, George Gliddon, and Louis Agassiz; and maintained that Adam was the progenitor of the Caucasian race, while the other races descended from Preadamite ancestry.
James Cowles Prichard argued against polygenism, wishing to support the account drawn from the Book of Genesis of a single human origin. In particular he argued that humans were one species, using the interfertility criterion of hybridity. By his use of a form of natural selection to argue for change of human skin colour as a historical process, he also implied a time scale long enough for such a process to have produced the observed differences.
Incompatible views of chronology
The Early Christian Church contested claims that pagan traditions were older than that of the Bible. Theophilus of Antioch and Augustine of Hippo both argued against Egyptian views that the world was at least 100,000 years old. This figure was too high to be compatible with biblical chronology. One of La Peyrère's propositions, that China was at least 10,000 years old, gained wider currency; Martino Martini had provided details of traditional Chinese chronology, from which it was deduced by Isaac Vossius that Noah's Flood was local rather than universal.One of the considerations detected in La Peyrère by Otto Zöckler was concern with the Antipodes and their people: were they pre-Adamites, or indeed had there been a second "Adam of the Antipodes"? In a 19th-century sequel, Alfred Russel Wallace in an 1867 book review pointed to the Pacific Islanders as posing a problem for those holding both to monogenism and a recent date for human origins. In other words, he took migration from an original location to remote islands that are now populated to imply a long time scale. A significant consequence of the recognition of the antiquity of man was the greater scope for conjectural history, in particular for all aspects of diffusionism and social evolutionism.