Chapter 2 - Early Humans
Very briefly, we will take a look at a few early humans, just to see the traits that they possessed and how those traits progressively evolved. Keep in mind that the classification of these fossils is somewhat arbitrary as species change gradually and most species live for tens of thousands of years after some of their members have evolved into other species. Nor can early human fossils be placed in the order in which they evolved by relying only on their cranial capacities because cranial capacities vary among individuals and the sexes (males skulls are larger and it is not always possible to determine sex). And the locations where the fossils were found are not proof that they evolved there.
The first known member of the Homo genus is Homo habilis ("handy man"), 1 so named because pebble tools were found with his remains. Habilis lived between 2.5 and 1.8 mya. The skull shown in Figure 2-1 was found in Tanzania, East Africa.2
The face is primitive, but the jaw projects forward less than in his simian predecessors, though his arms were long. There are no external nose bones, the eye sockets are large, and the teeth are considerably larger than in modern humans. Cranial capacity varied between 500 and 800 cc (with an average of 650 cc), which is small, considering that habilis was about 127 cm (5'0") tall and weighed about 45 kg (100 lb). Internal markings on the skull indicate that his brain had a humanlike shape. A bulge in the area used for speech on the left side of the brain (Broca's area), suggests that habilis may have been capable of rudimentary speech. He was also “the first hominid to add meat to its vegetarian diet.” (Arsuaga, 2001, p. 157; Haywood, 2000, p. 26). He probably descended from a gracile bipedal ape, such as Australopithecus afarensis or africanus. (Conroy, 1990).
Figure 2-2 3 shows an early Homo erectus from Africa that is now called Homo ergaster and Figure 2-3 4 is a drawing of what ergaster may have looked like.
Ergaster had a cranial capacity of 700 to 880 cc, lived about 1.9 to about 0.6 mya in Africa, and may have used fire. 5
Hand axes and cleavers were found with the fossils, but for a million years his tools did not improve. There is some doubt that ergaster originated in Africa as it does not seem to have an immediate ancestor there. (Dennell, 2005).
|Figure 2-2 ||Figure 2-3
A nearly complete ergaster skeleton, "Nariokotome Boy," (also called “Turkana Boy”) was found in Nariokotome, Kenya, Africa. He lived about 1.8 mya. Only about 10 years old when he died, he was already about five feet tall and would have been over six feet at maturity. Unlike earlier hominids, he could swing his arms when walking or running.
Homo erectus, who lived in most of Africa, southern Europe, SW Asia (the Middle East), SE Asia, Japan, and even some Pacific islands, had fire and systematically made tools. His earliest bones are almost 2 million years old and he did not become extinct until 27,000 ya on the isolated Indonesian island of Java (and perhaps even more recently, as we shall see below).
The term “Homo erectus” (“upright man”) is used somewhat broadly and once included some of the prior species, which may be considered to be early erectus. Like habilis, the face has a protruding jaw with large molars, no chin, thick brow ridges, and a long, low, and thick (½ inch in places) skull. But erectus was taller than his predecessors and had a larger brain (750 – 1225 cc), 6 smaller canine teeth, a smaller and less protruding jaw, shorter arms, and an external nose. The cover of this book, minus the suit, tie, and glasses, of course, shows what a tropical erectus may have looked like and Figure 2-4 (by Russell Clochon) depicts a northern >I?erectus. 7.
The OoA theory says that it was the African erectus that became modern man, then came the races, so the species Hs (and the subspecies Hss) arose before the races; the Multiregional theory says that there was an Asian erectus race and an African erectus race and they both became modern man, so the races came before the species Hs. And this book says the races arose before erectus, with Australopithecus, so the races came before the genus Homo.
Figure 2-5 shows front and side views of an early European erectus, classified as Homo georgicus. 8
The fossils, about 1.8 million years old and consisting of three partial skulls and three lower jaws, were found in Dmanisi, Georgia, of the former Soviet Union. 9 Georgicus has similarities to the habilis, ergaster, and erectus types found in Africa, though he was somewhat more gracile.
|Figure 2-5 Side View ||Figure 2-5 Front View
The brain sizes of the georgicus skulls vary from 600 to 800 cc. The height, as estimated from a foot bone, would have been about 1.5 m (4'11") and the
weight about 50 kg (110 lbs), shorter but heavier than the preceding African specimens because he lived in a cooler climate. 10 Note the large teeth (especially the large canines, which are very primitive), the sloping forehead, the heavy brow ridges, the projecting jaw, the absence of a projecting nose, and the bulge (“occipital bun”) at the back of the head. Georgicus may have been an ancestor to the African and Asian erectus (Lordkipanidze, 2006) and a predecessor of georgicus may have been an ancestor of the African ergaster and habilis.
Homo antecessor was found in Atapuerca, northern Spain, along with tools; it is dated at about 780,000 to 857,000 ya (Bermúdez de Castro, 1997). The fossils are fragmentary but similar to Nariokotome Boy (Fig. 2-2 & 2-3). The bones show definite signs of cannibalism. Antecessor was robust with an occipital bun, a low forehead, no chin, and a cranial capacity of about 1000 to 1150 cc. He stood 5½ to 6 feet tall, and males weighed roughly 200 pounds. Antecessor’s lineage is unclear, but he may have been on, or a branch of, the lineage that lead to Heidelberg man and the Neanderthals.
Scientists had trouble classifying many fossils from between about 800,000 and about 200,000 ya because they were not as primitive as Homo erectus, but yet were not really modern either, though somehow they still managed to get to northern England 700,000 ya. 12
Eventually, they were given the name Homo heidelbergensis, 13 aka “Heidi.” The skull capacity of Heidi is larger than erectus but still smaller than most living humans, averaging about 1200 cc, and the skull is more rounded than in erectus. The skeleton and teeth are usually less robust than erectus, but more robust than modern humans. Many still have large brow ridges and receding foreheads and lack chins. Figure 2-6 shows a 450,000 year old skull found in Arago Cave, Tautavel, France. 14
This was a young adult about 1.65 m (5’5”) tall, with a cranial capacity of 1150 cc. Note the receding forehead and the rectangular eye sockets. Heidi has many features that are similar to Neanderthals, such as a wide face, a heavy brow ridge, and a projecting jaw, suggesting that Neanderthals evolved from a European Heidi who, in turn, may have been a descendant of georgicus.
Neanderthals, 14 Homo neanderthalensis, lived between 350,000 and 24,500 ya (Finlayson, 2006) throughout Europe and the Middle East but, unlike Heidi, no Neanderthals fossils have yet been found in Africa. Neanderthals lived primarily in the cold north; they migrated to lower latitudes (e.g., Portugal, Israel) only during the ice age. Figures 2-7 15 and 2-8 16 show two variations.
|Figure 2-7 ||Figure 2-8
Note the larger and rounder eye sockets in Figure 2-7. The Neanderthals had an average skull capacity of about 1450 cc, slightly greater than that of modern humans, 17 but this may be due to their greater bulk rather than to their greater intelligence. 18 The skull is longer and lower than that of modern humans, with a marked bulge (“occipital bun”) at the back. Like erectus, Neanderthals had a receding forehead and a protruding jaw. The middle of the face also protrudes, a feature that is not found in erectus or sapiens, a feature that may be an adaptation to cold weather or, more likely, a partial retention of simian prognathism. There is a brow ridge without a gap in the middle, giving them a beetle-browed appearance; a chin is just beginning to appear.
Their barrel chests and short, stubby hands, fingers, and feet were adaptations for the cold 19 and, because of the lack of sunlight in the north, they would have had white skin (Arsuaga, 2001, p. 75), though they may have also been hairy. Men averaged about 168 cm (5'6") in height. Their bones were thick and heavy, and show signs that powerful muscles were attached to them, so they would have been extraordinarily strong by modern standards. Western European Neanderthals (sometimes called "classic Neanderthals") were usually more robust than those found elsewhere. 20A large number of tools and weapons have been found with them that are more advanced than those of Homo erectus. Animal bones suggest that Neanderthals were formidable hunters. They are the first people known to have buried their dead, with the oldest known burial site about 100,000 ya. We will return to Neanderthals in Chapter 25.
Archaic Man and Modern Man
Archaic man, Hs, first appeared about 200,000 ya and modern man, Hss, appeared about 160,000 ya. Modern humans have an average brain size of about 1350 cc. The forehead rises sharply, eyebrow ridges are very small or more usually absent, the chin is prominent with a cleft in the middle, the teeth are small, and the skeleton is gracile (light bones). Even within the last 100,000 yrs, the long-term trends towards smaller molars and decreased robustness can be discerned. Compared to modern Eurasians, humans about 30,000 ya were about 20 to 30% more robust and until about 10,000 ya were about 10% more robust; populations that have used food-processing techniques (e.g., cooking) the longest have the smallest teeth. (Brace, 2000).
The Cro-Magnons were the immediate predecessors of modern Caucasians. They lived in Europe about 40,000 to about 10,000 ya. They were slightly more robust than modern Caucasians and, like Neanderthals, they had brains that were larger (about 4%) than modern Caucasians, 21 though their skulls were thicker and brow ridges heavier. (Howells, 1948, p. 186).
With the appearance of the Cro-Magnon culture, tool kits started to become markedly more sophisticated. A wider variety of raw materials, such as bone and antler, were used and specialized tools were made for producing clothing, engraving, and sculpturing. Fine artwork, in the form of decorated tools, beads, ivory carvings of humans and animals, clay figurines, musical instruments, and spectacular cave paintings (Fig. 15-1a, 15-1b, & 25-3) appeared. (Leakey 1994).
Figure 2-9 shows a Cro-Magnon skull. 22
This 30,000 year old, fully modern, Cro-Magnon skull was found in Les-Eyzies, France. The skull shows traits that are unique to modern humans, including the high rounded cranial vault, and a nearly vertical forehead. There are no large brow ridges, nor a protruding jaw. Note how the eye sockets are slightly sloped and are flattened far more than in the other fossil skulls, possibly an adaptation to protect the eyes from the cold. 23 The flattened eye sockets that are observed in some North African skulls may be the result of Cro-Magnons migrating there during the worst of the last ice age.
Figure 2-10 is a graph that will give the reader some perspective on the known life spans of these species. 24
Table of Contents
1. There are no sharp skeletal differences separating early humans from their Australopithecine predecessors. “Whether habilis is in fact man or an advanced australopithecine is a matter of scientific dispute, and largely one of semantics.” (Ardrey, 1966, p. 259). For convenience, early humans can be lumped as stages of Homo erectus. Back
2. (KNM ER 1813). Photo from Wesleyan University Archeology & Anthropology Collections. Back
3. (KNM ER 3733) Picture from Museums Choice Fossils. Back
4. From Transvaal Museum, South Africa. Back
5. Ashes were found in a cave, but could have been carried there by moving mud or earth, or brush that had grown into the cave may have burned. (Arsuaga, 2001, p. 269). Back
6. Early erectus averaged about 900 cc, while late erectus averaged about 1100 cc. Back
7. A parody of a drawing from the University of Minnesota, Duluth, “Prehistoric Cultures.” Back
8. Skull D2700.
9. Skull D2282. Back
10. An example of Bergmann’s Rule. Back
11. (Parfitt, 2005). Boxgrove Man, a Heidi found near Chichester in Sussex, England with flint tools, was dated at about 500,000 ya. Back
12. The name is from Heidelberg, Germany, where one specimen was found, but Heidi has also been found in Spain and Africa. Heidi is also classified as Homo erectus heidelbergensis to indicate that it is a sub-species of Homo erectus. Back
13. Photo from the World Museum of Man. (Also see Figure 17-5). Back
14. Named for discoverer Joachim Neumann, who preferred his name in Greek, Neander (“new man”) plus “tal,” which is “valley” in German. Back
15. La Forressie (reconstructed), France. World Museum of Man Back
16. Chapelle-aux-Saints (reconstructed), France. World Museum of Man, a “classic” Neanderthal. Back
17. Wolpoff give a cranial capacity of 1525 cc for a 50,000 year old Neanderthal. (Lee, 2003, Table 1). Back
18. Neanderthals had a brain 4.8 times larger than expected for a mammal of their size, but our brains are 5.3 times larger, i.e., relative to body size, our brains are larger. (Ruff, 1997). Back
19. Bergmann’s Rule and Allen’s Rule, respectively. Back
20. (Trinkaus, 1979). Primates that eat mostly vegetables are robust (e.g., the gorilla) and those that eat mostly meat are gracile, but that does not apply to Neanderthals. (Corballis, 1991, p. 306). Back
21. The probable reason why we have smaller brains than our immediate ancestors is the change, about 12,000 ya, from hunting and gathering to farming, which selected against a large and costly brain as it was less needed. Back
22. Picture (now deleted) from Pleistocene”). See Figure 17-11 for H. floresiensis skull. Back