The Races of Humanity
Richard McCulloch

Since the 1950 UNESCO Statement on Race there has been an increasing tendency to claim, based on Boasian anthropology and in promotion of a multiracialist agenda, that the human races are "socially constructed" and their existence is not supported by science, meaning not biologically and genetically real. This essay is an account, consistent with current scientific knowledge, of how the human races we know historically and today were really constructed.

The human species is blessed with great variety and diversity. Its rich diversity resulted from its global distribution, which caused the different populations of humanity to be geographically separated and thus reproductively isolated. Reproductive isolation enabled divergence -- the process of divergent evolution -- to occur, causing the isolated populations to evolve in different directions, developing their own distinct ensembles of genetic traits and characteristics.

Divergent evolution is the process by which new life forms are created by the division and separation of life into different branches. Human evolution has seen its share of divergent branching. The generic name commonly used to refer to the genetically different populations, branches or divisions of humanity -- that share both a common biological ancestry and an ensemble of unique, genetically transmitted traits and characteristics which distinguish them from other populations -- is "race." But in the human species, as in any species enjoying a great degree of variety, the constant branching and dividing that characterizes the process of divergent evolution has created many different levels of branches and divisions, each of which possesses genetic traits which distinguish it from other branches or divisions at the same level. For purposes of taxonomic accuracy each of these levels should have its own specific name and definition. The first or highest level is called the species, and it is simply and objectively defined as including all those populations which are capable of interbreeding with each other and producing fully fertile offspring, and which do in fact interbreed under conditions of close and extensive contact. The term race is commonly used to refer to a branch or division of the species possessing genetically transmitted physical traits which distinguish it from other branches or divisions of the same level. Adding to this definition, it will here also be defined as including only those persons who are capable of reproduction with each other without the loss or significant diminishment or alteration of the racially-distinctive genetic traits of either parent stock. The genetically transmitted traits which distinguish a race from other divisions at the same level (i.e., other races) should not be diminished or lost by reproduction within the race. If racially-distinctive traits are lost or diminished by within-group reproduction then the population group is at a level of division too broad and inclusive to be accurately defined as a race. If it is too narrow to be defined as a species, as it does not include all those populations capable of interbreeding, then it is at a level between race and species, which will here be referred to as a subspecies.

The closest living relative of humanity, the still existing species most closely related to Homo sapiens, is the Chimpanzee, whose ancestral line separated and branched from the line leading to humans about 5.5 million years ago. Even after 5.5 million years of divergent evolution humans and chimpanzees still have over 98% of their genes in common, with only a 1.23% (Time, October 9, 2006) to 1.6% difference in their genome. The genus Homo originated with Homo habilis in the region of the Great Rift Valley in Kenya and Ethiopia in east Africa about two million years ago, where it continued to evolve, first as Homo ergaster and Homo erectus, then as Homo antecessor (750,000 years ago) and Homo heidelbergensis (600,000-250,000 years ago; believed to be the direct ancestor of Homo neanderthalensis in western Eurasia), and then as Homo sapiens idaltu, the earliest modern humans, with finds in Ethiopia dated to 195,000 and 160,000 years ago (Scientific American, Vol. 16, No. 2, 2006, p. 78).

The current (2019) general consensus is that there were at least three major migrations or expansions of the genus Homo out of east Africa into Eurasia, either crossing the Sinai peninsula from Egypt into the Levant (the coast of what is now Israel, Lebanon and Syria), or crossing the southern entrance of the Red Sea (the Bab el Mandeb) from Djibouti in Africa to Yemen in Asia, from where they spread throughout most of Eurasia and developed into a variety of regional "archaic" human populations. The first of these major expansions out of east Africa into Eurasia was about 1.8 million years ago, the second about 600,000 years ago (associated with the spread of the Acheulean culture), and the last shortly after 100,000 years ago. Beginning in 1987, based on genetic studies showing that the mitochondrial DNA (mtDNA) and the Y-chromosome of all living humans is derived from the last of these major expansions, the common view expressed in the popular press (called "Out-of-Africa") has been that the modern humans of the final migration completely replaced the regional archaic human populations from the first two major expansions. But beginning circa 2002 genetic studies by Alan Templeton and others have increasingly supported the view (called "Out-of-Africa-Again-and-Again") that although all our surviving mtDNA and Y-chromosome lineages as well as the majority of our other genes derive from the most recent expansion, a significant minority of our other genes have much older "coalescence" dates and must therefore derive from the regional archaic human populations of the first two major expansions. These studies indicate that some genes from the regional populations of the first expansion were assimilated and perpetuated by the populations of the second expansion, and that some of the genes of both of the first two (archaic) expansions were assimilated by the modern humans of the final expansion.

The first dispersal of modern humans probably began soon after the emergence of Homo sapiens idaltu in east Africa about 195,000 years ago, with some populations heading west into the tropical forest of the Congo basin where they intermixed with local archaic elements and evolved into the Congoid subspecies, others remaining in east Africa where they evolved into the Capoid or Khoisanid (San-Bushmen) subspecies, and others moving north to the shores of the Red Sea, where they became the progenitors of the population that eventually migrated out of Africa and populated the rest of the world, intermixing with regional archaic human populations they encountered in varying degrees, and evolving into the Australoid, Mongoloid and Caucasoid subspecies. By 130,000 years ago there were perhaps 10,000 modern humans living in different populations in different regions of Africa. About 120,000 years ago one of these modern human populations that had expanded up the Nile valley crossed the Sinai peninsula out of Africa into the Levant but no traces have been found of them after 90,000 years ago.

The final major expansion out of east Africa into Eurasia, perhaps numbering only a few hundred people at the beginning, crossed from northeast Africa to southwest Asia after 90,000 years ago, where they engaged in some intermixture with the local archaic Neanderthal groups. The descendants of this population gradually expanded and dispersed, with the initial expansion being along the southern coast of Asia. The where and when of these early human migrations was largely determined by geography, especially changes in climate and sea level. The first main split or division in the expansion occurred when some groups continued to move east while others remained in southwest Asia. The second main branching or division probably occurred after the eastward migrating group reached southeast Asia and intermixed with local archaic Denisovan elements, with one branch continuing to move eastward, reaching southern China by 68,000 years ago, where it experienced additional archaic Denisovan intermixture, and another branch remaining in the Burma-Thailand region, where it evolved into a proto-Australoid population, then expanded south through Malaysia and Indonesia, reaching New Guinea by 77,000 years ago and Australia by 65,000 years ago.

The eruption, or explosion, of the Toba super-volcano in northern Sumatra circa 74,000 years ago, the largest such explosion in the last two million years, perhaps 100 times larger than the Krakatoa event off southern Sumatra in 1883, covered the entire Indian sub-continent in several meters of ash, probably destroying almost all life, including the early human population in the area. The populations to the east and south of the eruption were spared its catastrophic effects, but the population in southwest Asia, and to a lesser extent the population in east Africa, probably suffered severe climate effects. The population in west Africa, protected by mountains to the east, was not as seriously effected. Within a few thousand years India was repopulated from the east by proto-Australoids.

By 50,000 years ago the population that had remained in southwest Asia had evolved into proto-Caucasoids and began to expand: to the northwest up the Tigris-Euphrates valley to the Levant by 45,000 years ago; and to the northeast through Central Asia to the mammoth steppe of Siberia where they developed into the Ancient North Eurasians. From the Levant they expanded north into Anatolia, from there entering Europe through the Balkans and spreading the Aurignacian culture across southern Europe by 43,000 years ago. From the steppes of Siberia they moved westward into Europe, spreading the Gravettian culture, about 33,500 years ago. Shortly after this another Caucasoid group expanded from the Levant across North Africa. In this same time frame the population in Indochina and southern China had evolved into proto-Mongoloids and expanded northwards into the steppes of eastern Siberia, branching into southern and northern Mongoloid groups. Some of the northern proto-Mongoloids in eastern Siberia intermixed with Ancient North Eurasian Caucasoids and subsequently migrated east across the Beringia land bridge, from where they moved south into the Americas.

By 30,000 years ago the divergent evolutionary branching or dividing of the human species had produced five main lines or subspecies which are still extant: the Congoid of West and Central Africa; the Capoid of East and South Africa (later replaced in East Africa by the Congoid); the Australoid of India, Burma, Malaya, Indonesia, New Guinea and Australia; the Mongoloid of East Asia (later expanding to the southwest into Burma, Malaya and Indonesia, largely replacing the indigenous Australoids) and the Caucasoid of Europe, North Africa and West Asia. These subspecies branched or divided in turn into separate races, and these races branched in their turn into subraces, as part of the continuing process of divergent evolution.

Beginning about 20,000 years ago, when the global human population was perhaps a million, the Last Glacial Maximum (LGM) pushed the population of northern Europe south to refuge areas (refugia) in southern France, northern Spain, the Balkans and Ukraine, while the now fully-developed northern Mongoloid population in Siberia was also forced south to eastern and southern China. Both populations were greatly reduced in number during this period. When the Last Glacial Maximum began to recede about 15,000 years ago (13,000 B.C.) the survivors of these populations expanded northward again from their refuge areas, with Scandinavia and Britain being occupied about 11,000 years ago, by which time the global human population had risen to perhaps 10 million.

Agriculture and the Neolithic (New Stone Age) period began about 12,000 years ago in southwest Asia and shortly after in China. Prior to this all the populations of humanity had always been "hunter-gatherers," living by hunting and gathering the fruits of the natural vegetation, which could only support a low-density population, with Caucasoid hunter-gatherers in Europe, North Africa and West Asia (including the mammoth steppe of Siberia); Australoid hunter-gatherers in India, southeast Asia, Indonesia, New Guinea and Australia; Mongoloid hunter-gatherers in East Asia; Congoid hunter-gatherers in West and Central Africa, and Capoid hunter-gatherers in East and South Africa. Agriculture supported a much higher population density then hunter-gathering, and so enabled massive population growth which spurred geographic expansion and the replacement of hunter-gatherer peoples by Neolithic farmers in varying degrees. Over the course of many generations the Mongoloid rice farmers of southern China expanded southwards into southeast Asia and across Indonesia, mixing with, assimilating and largely replacing the smaller aboriginal populations of Australoid hunter-gatherers. Similarly, the Caucasoid wheat farmers of southwest Asia expanded eastward into Pakistan and northern India where they mixed with and partly replaced the native Australoid hunter-gatherers, westward across North Africa and northwest into Anatolia, and starting about 8,500 years ago (circa 6,500 BC) from Anatolia across Europe, mixing with, assimilating and partly replacing the indigenous Caucasoid hunter-gatherer populations. This expansion had two branches, the first moving through the Balkans and up the Danube valley into central and northern Europe, the other moving through the Mediterranean to the Iberian peninsula and then north through western Europe, reaching the British Isles about 6,000 years ago (circa 4,000 BC), and is noted for creating megalithic structures such as Stonehenge (circa 2,500 BC).

The last major demographic and genetic shift in the Caucasoid region started about 5,200 years ago (circa 3,200 BC) with the expansions of what is currently (2019) referred to as the Yamnaya peoples of the Pontic-Caspian steppe, centered in what is now Ukraine. The Yamna are also known as the Kurgan people, with both terms derived from their custom of burying their dead in pit graves (local word "yama" for pit) under mounds or tumuli of earth (local word "kurgan" for mound or barrow). The Yamna-Kurgans, largely descended from the Ancient North Eurasians, were a semi-nomadic pastoral people who herded cattle and sheep on the steppe and domesticated the horse for use in herding and war. They were also the source and carriers of the Indo-European languages which they spread with their conquests and genes. By 2,600 BC the peoples of the "Corded Ware" (named after the style of their ceramic ware or pottery) aka "Battle-Axe" cultural area or "horizon" across north-central and northeastern Europe were genetically over 75 percent Yamna-Kurgan in ancestry, largely replacing the earlier mixture of hunter-gatherer and Neolithic farmer elements.

After 2,500 BC the predominantly Yamna-Kurgan elements of the Corded Ware culture blended with the peoples of the expanding "Bell Beaker" culture (also named after the style of their pottery) of western and central Europe and with this culture expanded into the British Isles, again largely replacing the existing population.