The earliest evidence for the emergence of truly modern humans is from Africa, with the discoveries of H. sapiens from Herto in the Middle Awash of Ethiopia (T.D. White et al., 2003) (Figure 9.1). These fossil specimens and stone artifacts have been dated to between 160,000 and 154,000 years ago by precise age determinations based on the argon isotope method (Clark et al., 2003). They are truly significant because they predate the classic Neanderthals and lack any of the Neanderthal derived features (see previous chapter). Like some previous (and later) hominin populations, there is evidence of postmortem modification to the bones, that is, cut marks. These
are best considered to be mortuary practices rather than cannibalism (T.D. White et al., 2003; see also Stringer, 2003). Indeed, the morphological condition of these specimens is intermediate between the condition observed in the African deme of H. heidelbergensis (defined by Bodo) and modern H. sapiens of today (T.D. White et al., 2003; see also Stringer 2003). As stated by Stringer (2003:693-694):
Despite the presence of some primitive features, there seems to be enough morphological evidence to regard the Herto material as the oldest definite record of what we currently think of as modern H. sapiens. The fact that the geological age of these fossils is close to some estimates obtained by genetic analyses for the origin of modern human variation only heightens their importance.
The stone artifacts associated with the Herto fossils are represented mostly by a Levallois-like tradition, including flake blades and points as well as some biface "hand axes" (Clark et al., 2003). The archeology of the Herto localities suggests that these hominins occupied the margin of a freshwater lake. There is evidence that they were involved in the butchery of large mammal carcasses, especially hippopotami, including a broad ontogenetic age span from newborn calves to adults (Clark et al., 2003).
The next earliest evidence for modern humans from this region are the discoveries from Singa, in the Sudan. Additional specimens soon followed, with discoveries at Dire-Dawa in Ethiopia, Jebel Irhoud and Dar-Soltan, both in Morocco, Border Cave in Kwazulu-Natal, Omo-Kibish (Omo 1) in Ethiopia, and Klasies River Mouth in the southern Cape. None of these fossils, except perhaps Irhoud, is older than 150,000 years, and most are less than 100,000 years old (B.A. Wood & Richmond, 2000).
The most recent attempt to define the morphological condition of modern H. sapiens has been that put forward by D.E. Lieberman (1995, 1998) and D.E. Lieberman et al., (2002). They suggest that modern humans can be defined by their globular braincase, a high and vertical frontal, substantial reduction in the supraorbital torus, a developed canine fossa, and a pronounced chin; overall the skull is relatively gracile in appearance. This condition can be attributed to reduced facial prognathism, associated with increased cranial base flexion, resulting in maximum reduction in neuroorbital disjunction (see also D.E. Lieberman, 2000). Further to this, D.E. Lieberman et al. (2002) identified distinct developmental processes of the skull (through ontogenetic studies) that are unique (autapomorphies) to modern H. sapiens. They confirm that anatomically modern humans are distinct in two main structural autapomorphies from H. neanderthalensis (and other "archaics"); these are in increased facial retraction and neurocra-nial globularity. These patterns are associated with a combination of shifts in cranial base angle, cranial fossae length and width, and facial length, which themselves are likely in response to increased size of the temporal and frontal lobes of the brain as well as their repositioning. Postcranially, modern humans are also clearly distinct from H. neanderthalensis, with elongated distal limbs relative to the trunk, with a trunk and pelvis that are more narrow, and with low body mass relative to stature (see B.A. Wood & Richmond, 2000).
The Omo-Kibish skeleton (Omo 1), which has been dated to 130,000 years ago (Stringer, 1998), is very modern in appearance, even though the bone table is relatively thick (Figure 9.2). While the face is missing, except for isolated fragments, the supraorbital tori are modern in appearance, the partially preserved zygomatic is reduced in size, and, finally, the mandibular fragment has a distinct chin, all confirming its status as representative of H. sapiens. The postcranial anatomy is clearly that of a tall and well-built male individual (Stringer & Gamble, 1993).
Klasies River Mouth, dating back to the last interglacial (between 120,000 and 90,000 years ago) is of interest not only because of the early appearance of modern humans, but also because it has been suggested that the cave dwellers practiced cannibalism, similar to that observed in the late Neanderthals from Krapina in Croatia. The fossils from this cave
system are clearly modern in appearance but with a mosaic of features: A frontal specimen has barely developed tori, of modern aspect (Stringer & Gamble, 1993), but of the half-dozen mandibles, the largest (which is above most modern humans in size) has the most prominent, modern chin, while the smallest (which is as small as any modern woman) has virtually no chin at all. The fragmentary nature of the material, the evidence of numerous impact fractures, the numerous cut marks on bone, the lack of long bones, and the evidence that the material had been burnt are what has suggested to some that these remains are part of a cannibal feast (see Deacon & Deacon, 1999), though it cannot be discounted that they are merely part of a secondary burial practice.
The remains from Jebel Irhoud in Morocco (Figure 9.3) are around 150,000 years old, perhaps a little more, and are defined by a combination of modern H. sapiens features with a few more primitive traits. For example, while the associated femur is robust and the teeth relatively large, the back of the skull of Irhoud 1 has a primitive appearance. It has a moderately developed supraorbital region, though it is clearly approaching the modern condition in its facial anatomy, with its broad, nonprognathic face, and its zygomatic is hollow. The mandible is marked by a distinct chin. Irhoud 2 is a calvaria, which is higher, rounder, and thoroughly modern. The Jebel Irhoud remains show affinities with the "proto-Cro-Magnons" from Skhul and Qafzeh (Stringer & Gamble, 1993; Jordan, 1999; Hublin, 2000). A circumorbital fragment from Zuttiyeh, in Israel, is about the same age as Irhoud, supporting our assertion that, from time to time, the Levant was part of the African theater.
The fossil evidence and associated dates from the African archeological record place the emergence of modern H. sapiens in the African continent to a minimum of 165,000 years ago. This is in full agreement with molecular studies that also depict modern humans diversifying in Africa around the same time. Molecular studies of mtDNA support the idea of recent African origins, and as discussed in the last chapter, the molecular studies of Neanderthal mtDNA also show a divergence from a modern human sample far outside the range observed in modern humans. Indeed, recent studies of nuclear DNA further refine the proposed dates of divergence from an African ancestor. As in studies of mtDNA, patterns of nuclear DNA distribution are significantly more variable in Africa compared to the rest of the world, and it has been possible to estimate the time of the first appearance of some of these patterns in Africa at between 200,000 and 100,000 years ago (Jordan, 1999; Klein, 1999; Wells, 2002; T.D. White et al., 2003; Oppenheimer 2003). The extremely limited genetic distance between modern H. sapiens populations in the rest of the world today strongly supports a recent and common ancestry from Africa.
Where in Africa did Homo sapiens originate, and from what species? As we have seen, the earliest remains are from both the far north and the far south and in between. Before these earliest specimens there is a hiatus in
Figure 9.3 ► Near-modern H. sapiens Jebel Irhoud specimens from Morocco, Africa: (a) Specimen 1, (b) Specimen 2.
time, and then we have the Florisbad skull (South Africa) at 259,000 years ago (Figure 9.4) and the Guomde skull (Kenya) at 272,000-279,000 years ago — both of them intermediate between Homo heidelbergensis and H. sapiens. It looks as if the African record, though less complete, is
complementing the European record: two H. heidelbergensis populations diverging, and each rapidly specializing in its own way, resulting in two sister species, individualizing at about the same time. This, of course, gets us no nearer to an actual place of origin. Or maybe there was none — maybe the "sapientizing" traits arose and spread almost instantaneously, imperceptibly, so that all African populations appeared to evolve together.
The emergence of modern H. sapiens is more often than not considered to be associated with the emergence of symbolic behavior, including art and decorative objects, which itself, it is argued, reflects for the first time evidence for complex and elaborate speech (see Noble & Davidson, 1996). It is also with the emergence of H. sapiens that we witness in the archeological record a substantially refined toolkit consisting of finely worked flint and bone tools, including needles and fishhooks — the first time we have evidence for sewn clothing or for fishing. There is, however, evidence from Africa of a disjuncture between the modern morphology of H. sapiens and the emergence of modern behavior: The remains from Klasies River Mouth, for example, are found with an African variant of the Mousterian technology (see Tattersall & Schwartz, 2000; B.A. Wood & Richmond, 2000).
Compared to the later explosion in Europe, there is little evidence for the widespread development of artistic or symbolic behavior within the earliest modern humans of Africa. We can, however, see an incipient behavioral shift toward this direction with incised ostrich eggshell fragments dated to around 50,000 years ago (Tattersall & Schwartz, 2000). Indeed, there is evidence of the development of an advanced tool technology at a number of early sites; thus by 80,000 years ago we see the development of bone harpoon points from Katanda in Zaire (Democratic Republic of Congo) and the remarkably upper Paleolithic-like industry of Howieson's Poort, which arose, flourished briefly, and then inexplicably disappeared in southern Africa.
We mentioned in the previous chapter that two sites in the Levant contain the remains of early modern H. sapiens and are associated with a typical African fauna. We consider this region at this time to be a biogeographic extension of the African continent rather than considering the traces of Homo sapiens coming out of Africa en route to points east and north. Mugharet es-Skhul, discovered between 1931 and 1932, and Djebel Qafzeh, excavated in 1933 and later between 1965 to 1975, are currently believed to fall between 120,000 and 80,000 years ago (see Stringer & Andrews, 1988; Valladas et al., 1998).
The near moderns from Skhul (Figure 9.5) and Qafzeh have a high and short braincase, round in profile, with reduced supraorbital tori and significantly reduced facial prognathism. The face is broad but with a low nasal aperture, and the zygomatics, while not inflated, do not run posteriorly as in Neanderthals, and the orbits are wide and low. Some primitive features are retained, including, in the case of Qafzeh 9, lower facial prognathism. In terms of their body proportions, they are even more like modern humans, with their elongated lower limbs and more slim physique, as if adapted for long-distance travel, though tropical populations today have a lankier build and longer limbs than do those from cooler climates, and the Skhul/Qafzeh proportions probably simply reflect their tropical origins.
In addition, an interesting three-dimensional morphometric analysis of Skhul and Qafzeh metacarpal fossil remains (finger bones) by Niewoehner (2001) indicates that these early modern H. sapiens had hands that were essentially like those of people from the Upper Paleolithic (and like us of today), unlike those of the Neanderthals, who are marked by a number of unique metacarpal features. Neanderthals are characterized by increased muscle mechanical advantages at the base of the thumb and on the ulnar and radial sides of the wrist, relative to the people from Skhul/Qafzeh and the Upper Paleolithic. Neanderthals are also distinct because of their increased development of muscle crests and fingertip widths. Together, these suggest that Neanderthals and the Skhul/Qafzeh peoples are distinct
sapiens Skhul V skull from Mount Carmel in Israel.
sapiens Skhul V skull from Mount Carmel in Israel.
from each other in the most functionally significant regions of the hand and that the Skhul/Qafzeh hand remains are morphologically and functionally within the range of modern humans, unlike Neanderthals. As Niewoehner (2001: 2983) concludes:
Given the patterns of between-sample morphological and functional similarities discovered, . . . the Skhul/Qafzeh hominids were most likely using oblique grips and finer finger movements more frequently than were Neanderthals. Notably, the skeletal evidence, . . . in the context of late Pleistocene patterns of modern human emergence, indicates that significant shifts in habitual manipulative behavior were associated with the early emergence of modern humans. Such behavioral shifts may well have been one of the primary components of the subsequent spread of early modern humans.
Perhaps the most interesting thing about the Skuhl/Qafzeh peoples is that they shared the Levant with Neanderthals. There are seven well-analyzed human habitation sites known from Israel spanning the late Middle Pleistocene and the Late Pleistocene: Oumm Qatafa, Zuttiyeh, Tabun, Qafzeh, Skhul, Hayonim, and Kebara. The deposits in the Tabun cave go right through from about 210,000 to 40,000 years ago. Those in the other sites are by no means as long-lasting, but the evidence they yield is entirely consistent, as shown in a remarkable series of papers by Tchernov (see Tchernov, 1998, and references therein): During Oxygen Isotope Stage 6, when the climate was cool, the Palearctic fauna spread down from Europe into the Levant. At 130,000 years ago, when the climate warmed up sharply at the beginning of Stage 5, the Afrotropical fauna swept in and replaced the Palearctic. When the climate slowly deteriorated, culminating in the onset of Stage 4 around 75,000 years ago, the Palearctic fauna came back again briefly. Stage 3, beginning about 63,000 years ago, represented a partial return to mild conditions and Afrotropical fauna again, ending around 32,000 years ago with the onset of the last glacial maximum (Stage 2). The Palearctic fauna included moles, hamsters, dormice, yellow-necked voles, red deer, wild goats, and horses. The Afrotropical fauna replaced these with African shrews, gerbils, the Nile rat, the multimammate mouse, hartebeest, ibex, warthog, and wild asses. It was not always a complete replacement; rather, the two faunas fluctuated in abundance, just as today in Israel the Palearctic fauna predominates on the highlands of the Carmel, and the Afrotropical fauna — what remains of it — predominates in the Negev, though it does penetrate the northern parts of the country to a limited degree. And along with the Afrotropical fauna we get H. sapiens; along with the
Palearctic fauna we get the Neanderthals. The two species of humans just fluctuated back and forth, like any other animal, until, at 40,000 years ago, Homo sapiens began, for whatever reason, spreading into the Neanderthal heartland of Europe. After that there were no more Neanderthals to repopu-late the Middle East.
As in Africa, there is a disjunction between biology and culture: Both of these near-modern human populations are associated with a local variant of a Mousterian technology. It is not until around 47,000 years ago, in the Negev at Boker Tachtit, that we see a transitional toolkit that points toward the development of an Upper Paleolithic tool technology (Goren-Inbar & Belfer-Cohen, 1998), defined by increasing frequencies of prismatic cores, with blanks modified into end scrapers, and the development of burins (Bar-Yosef, 1995). Yet more than fifty thousand years earlier, Qafzeh 9 was buried with arms folded and knees bent in a shallow grave, with an infant buried close to his feet. Qafzeh 11, a child, was found with the skull and antlers of a large deer, presumably buried as a complete head (Stringer & Gamble, 1993).
The available paleoanthropological, archeological, and molecular evidence now fully supports the origins of modern humans in Africa. It is likely that the African deme of H. heidelbergensis, known from individuals like Kabwe and Bodo, was ancestral to H. sapiens as indicated by the "intermediate" anatomical condition observed in the Herto specimens from the Middle Awash, Ethiopia (T.D. White et al., 2003; Stringer, 2003). Probably, as we have seen, H. heidelbergensis populations in Europe were ancestral to Neanderthals, though the species survived in parts of southern Europe, especially Greece (as indicated by Petralona) until quite late, while H. steinheimensis (if we really want to recognize it as a separate species) succeeded it in central and western Europe. It cannot be discounted, however, that either African or Levantine demes of H. heidelbergensis may have given rise to H. sapiens in the Levant, which then spread into Africa and, later, Europe, though the molecular evidence does point to an African origin. It is these African and/or Levantine demes of H. sapiens that eventually moved into Europe around 40,000 years ago (though 20,000 years earlier they had already settled in Australia — see next chapter), as attested by the presence of the H. sapiens child from Ksar Akil in Lebanon, dated to around 37,000 years ago, where an Upper Paleolithic blade lithic industry has also been documented at around 44,000 years ago. This is closely followed by the first documented appearance of this industry in Europe at Bacho Kiro in Bulgaria around 43,000 years ago, before finally making it all the way to Spain by 39,000 years ago (see Tiller, 1998; Gamble, 1999; Jordan, 1999).
Was this article helpful?