In OoA, today’s Africans evolved into modern man (Hss) in Africa, left Africa 65,000 ya and migrated to Asia, replaced all the Asians who were already there without interbreeding with them, and lost their African alleles and acquired completely new Asian alleles. In OoE, the Asians and the Caucasians evolved as two separate, but occasionally interbreeding, lineages from over 2 mya, but the African lineage did not so much evolve as it did acquire.
All humans evolved “up, up, and away” from an ape ancestor, but Africans did not evolve as far away, for the simple reason that they remained in the same type of environment that that ape ancestor lived in (i.e., they were close to equilibrium, Chapter 4, Rule 10) and were not subjected to the harsh selection of a northern climate. Furthermore, only a small part of the evolution of Africans was due to the selection of traits coded for by mutations that arose in Africans; instead, Africans mostly received mutations that had occurred in Eurasians when those Eurasians migrated into Africa and interbred with them. 1 Had no Eurasian hominins ever entered Africa, there would be no members of theHomo genus in Africa today.
The migrations of primates from Eurasia into Africa may have begun as long ago as the prosimians, followed by monkeys, quadrupedal apes, bipedal apes, Australopithecus, 2 erectus, northern Hs, and finally Hss. As time passed, the migrations came from one part of Eurasia, then another, then perhaps back to the first part again, but this time by a more evolved hominoid, and so on, off and on for millions of years.
Because the intervals in between migrations into Africa were not long enough for the newer and older migrants to evolve into different species, interbreeding to produce viable hybrids was possible and common. 3 As usual, only those hybrids who were best adapted for Africa survived. The numbers of more evolved migrants entering Africa at any one time was vastly less than the number of less evolved earlier migrants with whom they could interbreed, so migrants were absorbed, leaving behind few fossils; the only evidence of their presence is their alleles in their hybrid offspring. In this way, over millions of years, a huge variety of more advanced Eurasian alleles entered the genomes of African primates, and that is why Africans have the most genetic variation (Figure 19-2) 4 but no ancestors (quotes at the beginning of this chapter). 5
As those more advanced hominoids arrived in Africa from Eurasia they, and their hybrid offspring, pushed the less advanced hominoids away from their entry point in NE Africa. The earlier and more primitive arrivals did not go extinct immediately, but retreated to less desirable territories, dwindling in numbers but clinging on for many, many years before they went extinct. 6
Meanwhile, back in Eurasia, where the alleles were being generated that enabled hominoids to advance into modern humans, a similar process had already occurred, but hundreds of thousands of years earlier than in Africa. That is, when a new allele arose in Eurasia that was more adaptive in Eurasia, perhaps because it gave protection from the cold or the greater intelligence needed to survive the winters (see “Intelligence Enhancing Processes,” in Section IV), there was also interbreeding between those who had the alleles and those who did not, producing hybrids, and only those hybrids who were best adapted survived, just as in Africa. The difference, however, is that it took hundreds of thousands of years, if not millions of years, for the new alleles to spread to the individuals who would carry them into Africa. Thus, in the journey to become modern man, Africa was always hundreds of thousands of years behind Eurasia.
Now, a fair question is, “Why didn’t those alleles also arise in Africa?” No doubt some of the African-specific alleles 7 did and others eventually might have. But when the alleles arose in Africa, they arose as single alleles, so the individual who had them had to succeed or fail on the basis of that one allele. When the allele was brought in to Africa by the Eurasian migrants, it came not as a single allele, one with each individual, but as a set of compatible alleles. Those who had the set succeeded or failed on the basis of the entire set, which would have been much more beneficial than single alleles. Also, the negative effects of a few alleles in the set that were maladaptive in Africa may have been swamped by the positive effects of the remaining adaptive alleles in the package. Gradually, the maladaptive alleles would be lost 8 as individuals who lacked them, but not the adaptive alleles, were born. As discussed in “Intelligence as a Liability,” in Chapter 14 and later in this chapter, alleles for high intelligence were probably maladaptive in Africa and were lost as even those Africans in NE Africa now have low IQs. (Lynn, 2006a).
The migrants did not arrive with only their genes – they also brought their culture; and, since their culture was more advanced, this gave them a considerable advantage. An allele plus African culture may be a disadvantage, but an allele plus Eurasian culture may be an advantage, even in Africa. For example, an allele for digesting milk is of no advantage if people do not keep herds of herbivorous mammals, i.e., Africa, but is an advantage in Eurasia, where they do.
Although the early primate migrants into Africa were from the Eurasian tropics and could adapt easily to Africa, the later hominids were from a more northern climate and, because they were not adapted to the tropics, e.g., they had no resistance to tropical diseases; most did not survive for long and left few fossils. 9 Chapter 23 describes some of the earlier hominoids, up to Australopithecus, that may have migrated into Africa. The first Homo migrant into Africa may have been an early habilis that was better adapted to Eurasia than to Africa, but it had some advantages, such as superior tools and weapons, that were also advantageous in Africa. Georgicus is closely related to Africanhabilis, ergaster, and erectus fossils and fossils of Heidi have been found in Africa.
The Eurasian hominids interbred with the disease-resistant natives before the migrants died out, however, producing hybrids with various mixtures of the traits of the parent populations. 10 The hybrids that had both the disease resistance of earlier migrants and some of the more advanced traits of the Eurasian hominids were selected and survived, gradually advancing the Africans, though they were always hundreds of thousands of years behind the Eurasians. 11 The only trace of all the different migrants who entered Africa over a period of at least 2 million years is the large variety of alleles that are found in today’s Africans (Figure 19-2) and the traits they code for. Beginning with quadrupedal apes, the tree in Figure 26-1 shows how Africans advanced by means of waves of Eurasian hominids migrating there, bringing alleles for more advanced traits into the African gene pool, assuming a quadrupedal ape ancestor.
Figure 26-2 shows the location of some of the tribes in Africa; 12 the arrows show the three migratory routes in to (Suez and the Horn) and out of (Gibraltar) Africa.
Note that below the “African Whites” zone is a “Zone of Mixture” that extends across the continent, including the Horn of Africa, and most of southern Africa. The Hottentots and the Bushmen of the Kalahari Desert are right in the middle of the “Zone of Mixture.” The “Forest Negro” is the Congoids; they lived in the territory around the Congo and Niger River basins, where African Americans came from.
The Sahara Desert was “a nearly complete barrier to human movement north or south” except during the ice ages, when it was “a temperate, watered climate.” (Howells, 1948, p. 270). Thus, the only time that the Sahara Desert was habitable and easily crossed was the very time that the ice ages were driving Eurasians south in to Africa.
Note that northern Africa and what is now Egypt were occupied by whites, 13 and that migration out of Africa across Gibraltar would have been by whites. If Africans were migrating out of Africa, as OoA asserts, it is hard to explain how so much of northern African could have been white. Surely, the migrating Africans would not have become whites while still in Ethiopia and Egypt? One would expect all of Africa to have been black, especially the north, which the Africans were supposedly moving in to on their way to Eurasia. The fact that northern Africa was white and that “whiteness” declines as one moves south and west into the Congo suggests that any migrations were by whites in to Africa, not by blacks out of Africa. 14
Except for unpredictable droughts, African hominoids were in a stable environment, the same tropical environment that Africa has had for millions of years. The more stable an environment is, the less its inhabitants evolve (Chapter 4, Rules 4 and 6). That is, any new and unusual traits that arose in Africa were likely to be less advantageous than the traits African hominoids already had, traits that had worked well in Africa for millions of years.
Figure 26-3 (World Book Encyclopedia) shows the climate zones in Africa. The white population in North Africa along the Mediterranean Sea (Fig. 26-2) could have entered Africa from Gibraltar 15 or Suez (Alexandria) but, once there, moving south was feasible only when the Sahara was not a desert. By entering at the Horn of Africa into Ethiopia, however, movement south was possible at any time. Once in Ethiopia, the east coast of Africa could be followed south around the cape and north again partly up the west coast.
There are many very different populations in Africa, 16 but only a few of the most different ones will be discussed.
Because the Congoids are the most simian Africans and live in one of the areas most inaccessible to Eurasian migrants into Africa, they are likely to be descended from some of the oldest hominoids that migrated into Africa. The tropically-adapted traits of the Congoids, e.g., dark, hairless skin and short, wooly black head hair, were most likely brought into Africa by a tropics-specialized bipedal ape, probably a species of Australopithecus. Although Hs and Hss migrated south into both SE Asia and Africa, displacing more primitive hominids, in SE Asia the primitive hominids were driven onto islands and there was less interbreeding with them. In Africa, however, Hs and Hss did not survive as well. As a result, fewer Hs and Hss alleles entered the African genome, especially the more isolated Congoids, who therefore retained more of the simian traits of their ape ancestors.
The Nigerians are the African tribe that is genetically closest to the chimpanzee. (Deka, 1995). Nigeria is on the West Coast of Africa (Figure 17-6), making it difficult to reach from the Middle East, as Eurasian migrants would either have to cross the center of Africa or move south along the African coastline, around the cape, and back up north along the western coast past the equator. 17 Thus, of the Africans, the Nigerians either received fewer infusions of Homo genes from Eurasians or, of the various hybrids that were formed, those with the more primitive traits were better adapted for that territory and the other hybrids did not survive there. The area in which the Nigerians live is “the jungle of the Congo and of the Slave Coast of West Africa,” (Howells, 1948, p. 270), the home of chimpanzees and gorillas, suggesting that the known interbreeding between human and chimpanzee lineages 18 occurred in the Congo in the West African lineage. This would account for the simian traits of African Americans, who came from West Africa.
To understand the origin of the San and the Hottentots, it is necessary to look briefly at some Asians. As Asian hominids increased their numbers, they spread west along the coastline, then into Africa. (Olivieri, 2006). One population that did so was descended from a tropically-adapted Australopithecusthat lived in India. Today, a small remnant of these people still lives on the Andaman Islands (Fig. 26-4;Coon, 1962, p. XVIII), a string of small islands in the bay of Bengal east of India. About 60,000 ya, during the first ice age, the Andaman Islands were reachable from mainland India and these people probably lived in continental India as well. They either expanded their numbers and migrated into Africa or were driven there by more advanced northern hominids, who moved south to escape the ice age.
Although the woman’s buttocks are partially concealed in Figure 26-4, it is still obvious that they are enormous. Steatopygia (“fat ass”) is a highly unusual and very primitive trait as it is reminiscent of the buttocks of female apes and monkeys that become engorged with blood and bright red to signal ovulation to males. Although it is fat that is stored, probably to live off during periods of famine, the enlarged buttocks are attractive to males, just as the swelling of the buttocks is in other primates. Bustles worn by Victorian ladies in England in the 1800s had a similar effect on males. 19 Since enlarged buttocks are associated with apes, the presence of steatopygia in living people 20 suggests that a steatopygous hominid, probably a species of tropically-adapted Australopithecus in India, was an early migrant into Africa. 21
If ancestors of the Andaman Islanders made it to Africa, there could be some traces of that population in Africa. The Hottentots (aka “Khoi”) were a tribe closely related to the Bushmen, both using a monosyllabic “click” language. Their Y chromosome haplogroup A is the oldest human lineage (Knight, 2003). The Hottentots lived in Southern Africa near the Cape of Good Hope. Pure Hottentots no longer exist, some dying of smallpox and the remainder interbreeding with other Africans. There were some around in the 1800s, however, so unlike other extinct populations, we have descriptions and drawings of them and not just bones. The females were more unusual than the males; Figure 26-5 shows the most famous female, the “Hottentot Venus.” 22 The women, like the Andaman Island women (Fig. 26-4), are characterized by their enormous buttocks. The women also had large external genital flaps 23 and large areolae with inverted nipples. The face is flat, similar to an Asian’s, with only the teeth protruding and the incisors meeting at an angle, as in an African. (Coon, 1962, p. 646). The brain is smaller and simpler. 24
The Bushmen (aka “San”), a pygmy 25 hunter/gatherer tribe that lives in the Kalahari Desert in southern Africa, are one of the most primitive people on earth. Figure 26-6 is a photograph of a male Bushman. As you can see, even the males are steatopygous. It is steatopygia that ties Andaman Islanders, Hottentots, and Bushmen together as descendants of a single population.
Now take a close up view of another Bushman (actually a Bushman woman) in Figure 26-7. (Coon, 1962, plate V).
Although Bushmen have some African features (large lips, broad nose, small ears, and wooly hair) they also have some neotenic Asian traits (Cruciani, 2002), including light, yellowish skin, eye folds, and a flat face. 26 These traits are cold adaptations that occurred in East Asians when they became neotenic. Unlike other Africans, the Bushmen are monogamous, a trait of the cold north. Bushmen also have shoveled incisors and many newborn Bushmen even have “Mongoloid spots” at the base of the spine, both also Asian traits and Bushman DNA is 56% “Near Eastern.”27 Thus, there was likely interbreeding between the steatopygous Andaman Islander lineage and the neotenic East Asian lineage. 28 Interbreeding most likely occurred in Asia rather than in Africa because Bushmen first lived in northern Africa (where Eurasians entered Africa), before they were driven into southern Africa by new migrants. 29 Since the Bushmen were least capable of fending off other tribes, they now occupy the least desirable territory, the Kalahari Desert. However, the desert may have allowed them to escape malaria-carrying mosquitoes 30 and decimation from later, more advanced migrants.
The small size of the Bushmen may be because their tropically-adapted Australopithecus ancestors were small, 31 or it may be due to long-term calorie restriction, a condition that would have made a large energy-consuming brain a liability. When there is not enough food, individuals whose bodies require the least amount of energy have the best chance of surviving and individuals with smaller brains require significantly less energy. 32 As a result, brain size decreased, which gave Bushmen the lowest IQ (54) of any population yet measured and the lowest brain to body mass ratio of all human populations (even lower than the South Pacific aborigines).
As the Bushmen show, it is clearly possible to be neotenic, which is not a primitive trait in man, yet have a small brain. Conversely, as the Neanderthals show, it is equally possible to have primitive traits (heavy brow ridges, receding forehead), yet have a large brain.
“But originally they [East Africans] 33 must have belonged to an Upper Paleolithic [40,000 ya], large-skulled White stock of a longheaded variety, … Men like them were in South Russia in the Mesolithic [20,000 – 18,000 BC], and perhaps in the Near East.” (Howells, 1959, p. 313). “To put it simply, if skulls mean anything it is the Whites who have been solidly entrenched in East Africa since the latter Pleistocene, and anyone else is an interloper.” 34 This is, of course, consistent with the southward migrations of Caucasians into Africa.
Cro-Magnons, driven south by the ice ages, migrated into Africa 35 and interbred with the populations already there. 36 Figure 26-8 is a picture of a Caucasian-looking Somali (who immigrated to Russia). Although his Caucasian features are obvious, 37 the behavior of NE Africans is African, as is their IQ (Ethiopia = 63, Somalia = 68, Kenya = 72; Lynn, 2002a). The existence of the living populations of Bushmen and Somalis in Africa proves that there were ancient migrations of Asians and Europeans into Africa.
Thus, Africans seem to have descended from at least three species of tropics-specialized Australopithecus: (1) an Indian Australopithecus that had steatopygia, e.g., the Andaman Islanders, (2) an East AsianAustralopithecus that was neotenic and had specializations for the cold, e.g., the Negritos of the Pacific Islands, and (3) a more generalized Australopithecus that lacked the specializations of (1) and (2), but was specialized for the tropics. Some of the more generalized African lineages did not interbreed very much with Europeans and retained their simian traits (Congoids), while others interbred to a much greater extent with Europeans and lost more of their simian traits (NE Africans). The Australopithecus LCA of those three species would have been similar to species (3), also adapted for a warm climate but less specialized for the tropics. Having lived in the tropics for millions of years, the species (3) Australopithecus would have had the simian prognathism (Figure 25-10) of their ape ancestors plus the specializations of bipeds for the tropics, e.g., sweat glands, dark, hairless skin, and short, wooly, black head hair.
Figure 26-9 is an interesting tree from (Cavalli-Sforza, 1994).
Note that Caucasians are in the center of the tree, strongly suggesting that both East Asians and Africans descended from, or received genetic input from, the generalized Caucasian lineage, as in the OoE theory. As usual, the genetic distance from Caucasians to Africans is large, but note that the Africans that are farthest from Caucasians are the West Africans (e.g., Nigerians) and the Pygmies, indicating that they are descendants of the first migrants into Africa. The short stature of the pygmies is consistent with the short stature of Australopithecus. The West Africans live near the chimpanzees and are the most simian of the Africans, which is consistent with an early generalized Australopithecus from Eurasia entering Africa and interbreeding with chimpanzees. The next migrants were the steatopygous Australopithecines, probably from the Orient, then India, who became the San (Bushmen and Hottentots). And the last migrants were modern Caucasians, probably from the Middle East, who interbred with earlier migrants and became the NE Africans.
An “anomaly” is something that does not seem to fit into a theory or explanation. One can consider an anomaly as an annoyance to be swept under the rug, hoping no one will notice, or as an opportunity, a clue to a deeper understanding. Boskop is an anomaly that any theory of human origins must deal with, though it may not yet be possible to determine which theory of his origins is correct.
There is little information about Boskop (aka Homo capensis), just a few pieces of a skull found in the Transvaal region of NW South Africa.Figure 26-10 is the skull (reconstructed by Broom), with the darker areas being the pieces found. Although the skull is dated at only 30,000 to 10,000 ya, 38 the skull bones are thick and the jaw is massive and projecting. 39 It is described as “modern-looking” (neotenic) because the high forehead and larger skull capacity look European, but the protruding heavy jaw is similar to the African skull in Figure 9-4. It has a cephalic index (breadth of skull divided by length times 100) given as 75.1 by one researcher and as 76.19 by another, only slightly higher than that of living Africans (<75, see (4) in Table 9-1), which suggests some Caucasian heritage. However, it had an endocranial capacity estimated at 1860 cc, higher than Europeans (1441 cc), much higher than living Africans (1338 cc), and higher than Neanderthals (1450 cc) or Liujiang (1480 cc). Moreover, Boskop is said to be related to Hottentots and the Bushmen, 40 who have a very small cranial capacity. How did Boskop, living in South Africa, acquire those traits?
Given that Boskop has some Hottentot-Bushman features and some Caucasian features, one possibility is that Cro-Magnons entered the horn of Africa 41 and migrated south, interbreeding with the natives along the way, though that does not explain the large skull capacity.
What we do know is that today there are no large-brained Africans. The disappearance of large-brained Africans, such as Boskop and the Eurasians who contributed alleles to the Bushmen (IQ = 54, Lynn 2006a, , p. 169) and the Somalis (IQ = 68; Lynn, 2002a), is evidence that the optimal intelligence in Africa is much lower than the optimal intelligence in Eurasia. (See “Intelligence as a Liability,” pp. 120-123.) In North Africa, it was the lighter-skinned, somewhat more intelligent (ave. IQ = 84, Lynn, 2006a, p. 80) hybrids who were best adapted, but below the Sahara it was the darker-skinned, less intelligent (ave. IQ = 67, Lynn, 2006a, p. 225) and more erectine individuals who had the advantage. Thus, any large-brained Caucasians who migrated into Africa would be burdened by their excess brain tissue and would become extinct, as Boskop did.
Today, southern Africa, where Boskop was found, is cooler, but not as cold as Eurasia. Large brains would not be as useful due to the absence of a winter cold enough to cover the ground for many months with snow. Figure 26-11 shows the monthly temperature range for Bloemfontein, the coldest of the major cities in South Africa 42 (due to its high elevation), and even there the temperature barely reaches freezing.
However, there were times in the past when the temperature in Africa, at least at higher elevations, was colder and large brains, and greater intelligence, would have been an advantage. Under those conditions, the optimal brain size for Africa would have been greater and large-brained northerners who migrated there to escape the cold of Europe could have maintained or even increased their brain size. As the African climate warmed again, large brains again became a liability and those who had them died out. 43
Two skeletons found in Grimaldi Cave on the Mediterranean, near Mentone, Italy are another anomaly. They were dated at 30,000 BP and appear to be a Negroid-Caucasoid mixture, but more Caucasoid than Boskop. 44 One was a 5’2” woman and the other was a 5’1” teenage boy (Fig. 26-12). 45 The Negroid traits are the wide nasal opening, large teeth, forward-projecting incisors and jaw, small chin, and long forearm and legs, and the Caucasoid traits are the high forehead, meeting of frontal skull bones, large cranial capacity (1375 and 1580 cc for the woman and boy, respectively), and prominent nose bones.
A Cro-Magnon was buried above the skulls and a Neanderthal was buried below them, suggesting Neanderthals were there first, then the Grimaldi hybrids came, and finally Cro-Magnons took the territory. A possible explanation is that the ice ages drove Cro-Magnons into Africa where they interbred with Africans forming the Grimaldi hybrids. When the ice receded, the hybrids advanced north around the Mediterranean. They were later replaced by un-hybridized Cro-Magnons.