Tropical aboriginal populations are the last remnants of tropically-adapted erectus populations, pushed south by more advanced Hs andHss northern populations. They survived by seeking refuge on isolated and less desirable territories, such as islands, mountains, and dense forests. As they retreated and diminished in numbers, they interbred with those northerners, picking up Hs and Hss alleles and traits. The resulting erectus hybrids had traits of both parent populations, but only those individuals who had traits best adapted for the tropics survived. Today, erectus hybrids and Hs can be found in the aborigines of India, the Andaman Islands, some South Pacific Islands, the Philippines, New Guinea, New Zealand, Australia, and elsewhere in Asia.
Australian aborigines form three distinct populations, one living in the rainforests of North Queensland (“pygmies”), one living mostly in the southern desert areas (“desert aborigines,” of macrohaplogroup “N”) and the other living mostly in the northern coastal areas (“coastal aborigines” of macrohaplogroup “M”); see Figure 20-3. 1
As noted in Chapter 5, the last two ice ages occurred between about 73,000 and 55,000 ya (the “first” ice age), and between about 30,000 and 12,000 ya (the “second” ice age). During those two ice ages, vast quantities of sea water were locked up in ice (i.e., water evaporated and fell as snow, but did not melt), which lowered sea levels enough to make crossing from SE Asia into Australia not only feasible but necessary to escape more advanced populations moving south away from the increasing cold. Figure 27-1 shows sea levels during the second ice age (grey areas were dry land).
Toba, 73,000 ya, wiped out a large portion of the people living in SE Asia, making it easier for northern Asians to move south. Who got to Australia first depended upon the severity of conditions and how advanced the SE Asian populations were at that time. The first ice age was not as severe as the second, so the sea levels were higher, but the “N” macrohaplogroup populations, who were from India and northern Asia, 2 were more advanced at that time than the “M” macrohaplogroup populations and, using small rafts to island hop, got to Australia at least 60,000 ya. (Figure 20-3, shows how close Indians (in India), SE Asians, and Australian aborigines are in the N macrohaplogroup.) Later, during the second, more severe ice age, when the seas were still lower (about 25,000 ya), a more primitive, but numerically greater, “M” population in New Guinea was able to cross over to Australia, pushing the earlier arrivals into southern Australia and the desert. No doubt there was some conflict between the earlier and later migrants. Although there was probably some interbreeding between the coastal and desert aborigines, the coastal aborigines today are still more primitive than the desert aborigines.
Figure 27-2 shows skin color for aborigines in Australia and New Guinea, which generally coincides with the M and N macrohaplogroups. (Brace, 2000). The equator (orange line) is just north of New Guinea, so skin colors are reversed in the southern hemisphere, with the darker skin color in the north, closer to the equator, and the lighter colors in the colder south. Because the aborigines in Australia and on South Pacific islands were isolated and did not receive much inflow of more evolved alleles from northern populations, they are among the most primitive populations. When modern Europeans first arrived in the 1600s, the Australian aborigines “had no bow and arrow, to say nothing of such arts as pottery or agriculture,” and they cooked by “tossing their meat into the fire.” (Howells, 1948, p. 285). The Australian aborigines were the only people who did not make the connection between having sex and giving birth. 4
For largely political reasons, the existence of the Australian pygmies is not well known. (Windschuttle, 2002). These pygmies lived in the rainforest until missionaries drew them out and mixed them with other aborigines; now they are almost extinct. The adult males were between 4½ and 5 ft. tall and the women ½ ft to a foot shorter. (Fig. 27-3). 5
“Their small size, tightly curled hair, child-like faces, peculiarities in their tooth dimensions and their blood groupings showed that they were different from other Australian Aborigines and had a strong strain of Negrito in them.” (Norman Tindale, Australian anthropologist). Their tropical adaptations and small size suggest a lineage from a tropically-adapted Asian Australopithecus, and their “child-like faces” suggest interbreeding with a neotenic Asian Australopithecus, as described in the previous chapter. The presence of people of small stature in Australia, Africa (Bushmen), and in Indonesia (the Hobbits), is consistent with Bergmann’s rule, that northern populations are larger. 6
There are no fossils of these pygmies, so anthropologists assume that they did not arrive in Australia prior to about 40,000 ya. However, their Australopithecine traits suggest that they were in Australia long before that, because Australopithecines had disappeared from mainland Asia long before then. There were many earlier ice ages that would have provided access to Australia from the mainland. (Figure 5-1).
The tree in Figure 24-5 shows two distinct types of tropical aborigines, the southern desert aborigines (also living on the west coast of Australia, and the open grasslands and parklands of the south and west of the continent.), descended from a generalized archaic, and the coastal aborigines, descended from a tropical Australopithecus. The desert aborigines look like primitive Caucasians, with light skin and wavy or straight hair that can be blond. (Fig. 27-4; also Figure 22-5). 7 No, the children’s hair was not dyed blond. Amazing as it seems, some desert aborigines really do have straight or wavy, naturally blond hair. (Note 17 in Chapter 10). The child on the right has some simian prognathism and the second child from the left has a broad nose with upturned nostrils.
Note that the adult in the back, probably a mother of at least some of the children, has darker skin and hair; Caucasian children also have lighter skin and hair than adults. 8
Unlike the desert Australian aborigines, the coastal aborigines are more anatomically specialized for the tropics and look Negroid, with dark skin and wooly black hair. In those respects, they are similar to the Negritos of the South Pacific, the Africans, Andaman Islanders, and Melanesians (which includes people on New Guinea). They are the descendants of a tropically-adapted Australopithecus and a tropically-adapted erectus 9 and have retained many of those traits.
At least 2 mya erectus was living in Java and New Guinea (Roberts-Thomson, 1996) and there are Australian and New Guinea natives living today who have more erectine traits than even Africans. The two ice ages were not as severe in Asia as in Europe and the migrations from the north were therefore also less severe, enabling more primitive people to survive on South Pacific islands. The lower sea levels during the first ice age would have enabled erectus to reach New Guinea and other islands, but not Australia. The higher sea levels in between the two ice ages would isolate them, but the still lower sea levels during the second ice age would permit them to walk from New Guinea to Australia (Fig. 27-1). They, in turn, pushed the desert Aborigines away from the coast and into the central desert, the same fate that befell the Bushmen in Africa.
The northern coastal aborigines are “tall, dark, less hairy, and very lanky.” (Howells, 1959, p. 326). They have some erectine features, such as marked protruding jaws and brow ridges, small cranial capacities, low IQ, and black, curly hair. 10 Figure 27-5 compares the skulls of a recent (after 1800), but more primitive, northern coastal Australian aborigine (Pintubi-1, from the Great Sandy Desert of Western Australia) to a modern Caucasian. 11 The primitiveness of the robust aborigine skull is unmistakable and it would not be unreasonable to classify it as Homo erectus. 12 Note the brow ridges, sloping forehead, protruding jaw, and large eye sockets, though those traits are not as pronounced as in some older erectus skulls; only its chin is modern. 13
Figure 27-6 is a photograph 14 of a contemporary coastal Australian aborigine. The aborigine in Figure 27-6 has many primitive features, such as considerable simian prognathism (p. 215) and a small broad nose.
The South Pacific aborigines, e.g., the Negritos of Malaysia (the “Semang”) and the Philippines (the “Aeta”), and the highlanders of New Guinea, also have some of these traits, but are even more erectine, having a smaller cranial capacity, 15 thick, heavy bones, 16
large teeth, a smaller chin, a broad nose, very black skin, and frequently short curly or woolly black hair. Figure 27-7 shows a European standing between two Negritos. 17 One can easily understand how the smaller, primitive people in the tropics would have been displaced and defeated by the larger and more advanced people who migrated there from the cooler climates.
As mentioned previously, although the Negritos look like little Africans, they are genetically the most unrelated people to Africans on the planet. 18 The large genetic distance between Africans and Negritos suggests that their LCA was likely a tropically-adapted Australopithecus that lived more than 2 mya and possessed the tropical traits that the aborigines and the Africans have in common.
Modern man, Hss, evolved from a primitive mammal because, at each stage in his journey, the next step paid off with greater reproductive success. Now, in the final section, we see whether man will continue down the same path, becoming ever more “human,” or whether reproductive success will take us back to where we came from.