The Evolution of Homo Sapiens

The noted blogger Fjordman is filing this report via Gates of Vienna.
For a complete Fjordman blogography, see The Fjordman Files. There is also a multi-index listing here.


Homo sapiens, our own species, is distinct from other mammals: great apes such as chimpanzees, gorillas and orangutans and from early hominids. At some point between 8 and 4 million years ago gorillas and then chimpanzees split off from the evolutionary line that would lead to humans. As Michael H. Hart explains in his fine book Understanding Human History, Australopithecus afarensis, our likely hominid forefather, lived in East Africa about 3.5 million years ago. The Australian anthropologist Raymond Dart (1893-1988) discovered the first fossil of an Australopithecus africanus, a slightly more evolved version of A. afarensis, in 1924 in southern Africa. It was neither ape nor human and caused a stir at the time. Prior to this find, most Western scholars had believed that humans evolved in Eurasia.

Louis Leakey (1903-1972), the son of British missionaries, was an archaeologist and naturalist working in British-ruled East Africa. He went to school at Cambridge University in England, majoring in anthropology and graduating in 1926. From the very start Louis felt that our species arose in Africa, a concept which is now widely held but was controversial at that time. Through their tireless exploration and research, Louis and his English wife, the archaeologist and anthropologist Mary Leakey (1913-1996), made the Olduvai Gorge in the Serengeti region in northern Tanzania, famous for its wildlife, their domain. They made a series of spectacular paleoanthropological and archaeological discoveries in East Africa and founded a Leakey family dynasty of leading scientists that is currently in its third generation.

Lucy, the skeleton of an Australopithecus afarensis that lived 3.2 million years ago, was discovered in Ethiopia in 1974 by the American paleoanthropologist Donald Johanson (born 1943) along with the French anthropologist Yves Coppens (born 1934). The genus Homo diverged from Australopithecines more than two million years ago with Homo habilis, which made very crude stone tools called Oldowan after the Olduvai Gorge. About 1.8 million years ago a new species, Homo erectus, arose in East Africa, the first hominid to spread out of Africa. The earliest fossil of Homo erectus (“human that stands upright”), the Java Man, was discovered by Dutch physician and paleoanthropologist Eugène Dubois (1858-1940) in 1891 on the island of Java, then under Dutch colonial rule. H. erectus existed not just in Africa but in parts of Eurasia as far as Java in Southeast Asia, but apparently never settled in Australia or the Americas; this was achieved by early modern Homo sapiens during the past 40,000 years.

The exact evolutionary sequence leading to our own Homo sapiens is disputed, but a commonly held view is that we derive from Homo erectus, which again derived from Homo habilis, which in turn derived from Australopithecus afarensis. The prevailing view among anthropologists is that Homo sapiens originated in Africa about 350,000 years ago. They are often referred to as “archaic Homo sapiens.” About 100,000 years ago Homo sapiens sapiens, which includes all modern humans, arose in sub-Saharan Africa and eventually spread throughout the entire world, displacing all other variants of the hominid family.

There were undoubtedly other, less evolved, Homo species which are now extinct. It is not impossible that there was some multiregional evolution or admixture with existing Homo populations when anatomically modern men moved into Eurasia; this remains a hotly disputed area of paleoanthropology. For example, Homo floresiensis (“Flores Man”) is a possible species discovered in 2003 on Flores in Indonesia. It apparently survived until after 10,000 BC, which would make it the final branch of archaic humans to go extinct. Yet there is not yet a consensus on the matter, with some scholar viewing it as a version of Pygmies.
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A very widespread view among scientists is the “Out of Africa” theory of the recent African origin of anatomically modern humans. According to this theory, Homo sapiens originated in Africa, moved into Eurasia and beyond 50-60,000 years ago and replaced other, more archaic human species. The British anthropologist Chris Stringer (born 1947) is one of the leading proponents of the recent “Out of Africa” theory.

A strikingly large proportion of leading evolutionary biologists, starting with Alfred Russel Wallace and Charles Darwin, come from the English-speaking countries. The American physical anthropologist Jeffrey H. Schwartz (born 1948) researches the origins of primates, including humans. Henry McHenry (born 1944) Professor of Anthropology at the University of California, Davis, studies evolutionary history of hominid bipedalism, locomotion (e.g. walking, jogging, running) on two legs. It is not uncommon to see animals standing briefly on two legs, but only a few of them do this consistently. Most other animals, including chimpanzees, gorillas and even cats, may stand on two legs on a temporary basis in order to perform a particular function. Today, only humans and birds demonstrate habitual bipedalism.

The human family tree grows more complex all the time, but I personally believe that the out-of-Africa theory is largely correct. The pathologist Robin Warren (born 1937) in 1979 discovered the bacterium Helicobacter pylori at the University of Western Australia together with physician Barry J. Marshall (born 1951). In 2005 they shared the Nobel Prize in Medicine for their discovery of H. pylori and its role in gastritis and peptic ulcer disease. Thanks to them, peptic ulcer is no longer a chronic, frequently disabling condition, but a disease that can be cured. Infection of the stomach by H. pylori is ubiquitous among humans, but genetic diversity in it decreases with geographic distance from Africa. Like its hosts, simulations indicate that the bacterium spread from East Africa almost 60,000 years ago.

Two prehistoric migrations peopled the Pacific. One reached New Guinea and Australia, and a second, more recent, one extended through Melanesia on to the Polynesian islands. These migrations were accompanied by two distinct populations of Helicobacter pylori. The first split from Asian populations 31,000 to 37,000 years ago and, in concordance with archaeological history, remained largely isolated thereafter in Australia until the European colonial period. The second human expansion 5000 years ago dispersed one branch of the large Austronesian language family into Melanesia and Polynesia. These languages have their greatest diversity in Taiwan outside of mainland China, where the Austronesian expansion probably began just before 3000 BC, at roughly the same time as the Indo-European expansion began in Europe. Austronesian-speaking peoples gradually spread throughout the islands of Southeast Asia and from there on to the Pacific islands in several waves as they invented improved outrigger canoes capable of undertaking such long sea voyages.