This is taken from my book The Emergence and Nature of Human History, Volume One. The section of the book from which this is taken is a chronology of the emergence of consciousness. The chronology employs Carl Sagan's device of condensing the Universe's age down to one year, with the Big Bang occurring on 1 January. The section also measures time through the use of an imaginary timeline one million meters in length. In this scale of time, all of the events here began about 10:30 pm on 31 December, and were 999,818 meters up the line. The chapter is lengthy, so I published part one in the middle of last night.
(This is a re-post.)
WHEN AND WHERE DID ERECTUS RADIATE THROUGHOUT THE EASTERN HEMISPHERE?
It would appear, according to many researchers, that there were quite possibly migrations of erectus radiating from the African continent before 1.8 million ybp. Erectus got as far into southeast Asia as Indonesia. In fact, the first erectus remains were discovered by Eugene Dubois in Java, and formally described in 1894. The specimen was originally called Pithecanthropus erectus. Since that first discovery, scientists researching human origins have attempted to place all the known erectus specimens into a chronological and geographical framework. What have they ascertained?
In eastern Africa, there were ergaster/ erectus types perhaps as early as 1.9 million ybp and perhaps as late as 700,000 ybp. Outside of Africa, there were erectus-like primates at Perning, on the island of Java at about 1.8 million ybp. Erectus remains have been discovered at several places in Indonesia (especially Sangiran), and there may have been relict populations of the species living in Indonesia less than 100,000 ybp. At around 1.7 million ybp, erectus-like primates were at Dmanisi. [Although this has been disputed, as we saw.] In China, erectus remains date back at least to 1.1 million ybp, and there may have been erectus living in China as late as 200,000 ybp.34 In the Middle East, evidence of hominin presence has been uncovered at Ubeidiya, Erq el Ahmar, Gesher Benot Ya`aqov, and Ruhama in Israel (among other Middle Eastern locales), and at the first three sites tools associated with erectus have been unearthed. There is substantial evidence of hominins (perhaps erectus/ ergaster) in South Asia. The status of erectus in Europe is in dispute, as we will see below.
Homo erectus remains in China were first discovered at Zhoukoudian, near Beijing. Scientific excavation and analysis of these remains began in the 1920s and accelerated in the 1930s. [Unfortunately, the original specimens that were dubbed “Peking Man” by the archaeologists of the time were lost in the Second World War. Casts of the originals were preserved, however.] Significant erectus remains have been uncovered at several other Chinese sites, most notably Longgupo Cave (along the Yangtze River), Gongwangling on the Yellow River (where the oldest erectus remains in China have been discovered), and Hexian.35
Recent research indicates that erectus occupied Zhoukoudian as early as 770,000 ybp.36 Zhoukoudian specimens, which are designated by the abbreviation ZKD, have endocranial measurements ranging from 1110cc to the largest specimen, ZKD X at 1225 cc. Recently measured ZKD V came in at 1140cc. Despite their great distance from Africa, the Zhoukoudian specimens bear certain important similarities to African erectus samples, especially to the cranial morphology of KNM-ER 3733 and KNM-WT 15000.37 There are Chinese paleoanthropologists who have tried to make the case that early sapiens interbred with late erectus populations in China, but the genetic evidence does not support this contention. (See below)
Was erectus in Europe? There were most definitely human populations in Europe prior to the evolution of sapiens, but their exact identity is a matter of dispute. There is evidence from Atapuerca that there was indeed human occupation of Europe in the Early Pleistocene. The evidence is in the form of a human mandible with some dentition, a set of very primitive tools, and some animal remains that may indicate human butchering. The date of these finds, 1.2 to 1.1 million ybp, is the earliest yet established in Europe. The affinity of the human specimen is uncertain, although the scientists analyzing it suggest that it might from a species known as Homo antecessor, hypothesized by some scientists to have been a transitional species between erectus and heidelbergensis in Europe.38
WHAT APPEAR TO HAVE BEEN THE CHIEF CULTURAL TRAITS ASSOCIATED WITH ERECTUS?
A culture may be thought of, broadly, as a way of life handed down through time within a given set of humans. It is the sum of a group’s ideas and beliefs, methods of achieving objectives, and traditions, in short its learned behaviors. It is also the sum of a group’s characteristic material objects and the uses to which they are put. It is primarily conveyed by language of some sort, although it can also be acquired by imitation. We will examine the concept of culture very thoroughly in a subsequent volume, but for now it will suffice for us to say that the way of life established by the various populations of erectus had a major effect on the development of human life on this planet.
The various erectus populations of the eastern hemisphere possessed rudimentary tools that are broadly known as Acheulian. The characteristic Acheulian-style tool was the bifacial hand axe. Other known Acheulian tools included cleavers, choppers, and picks. Acheulian industry is thought to have emerged between 1.7 and 1.5 million ybp, and its typical tools seem to have made their first appearance in east Africa. Recent research indicates that Acheulian tools do not seem to have originated out of the older Oldowan tool tradition. They appear to have been, rather, a technological innovation made to accomplish a broader range of tasks than Oldowan tools. They co-existed with Oldowan tools in east Africa for about a million years.39 Three researchers who have done extensive work on ancient tools at Gona in Ethiopia have summarized the possible reasons that some scientists (mistakenly, in their view) see a transitional stage between Oldowan and Acheulian tools:
[Those who contend there was a transition] may be conflating separate cultural/technological/ecological changes occurring in the Late Pliocene/Early Pleistocene that may or may not be interconnected, such as: (1) the ability to knock off large flakes, (2) the ability to flake invasively and shape tools purposefully with predetermination or preconception of form, (3) the standardization of tool shape and/or technique, (4) changing diet and ranging patterns, (5) possible changes in group size and/or organization, and (6) possible changes in learning styles and abilities. Early Pleistocene hominins may have “experimented” with these developments initially until all elements came together in the classic Acheulian.40It should be noted that the authors are careful to say that although Acheulian tools are usually associated with erectus/ ergaster, the appearance of erectus-like primates and the earliest Acheulian tools are not contemporaneous, and may in fact be separated by more than 100,000 years.41 Still the implications of these findings are significant. Early humans, as they ranged farther and farther out into the world and encountered increasingly diverse challenges, devised technologies suitable to the tasks with which they were confronted. Moreover, these technologies may be the product of a profoundly important synergy: the coming together of higher levels of intelligence, a wider cultural tradition, and more complex modes of social life, all of which may have come together to form a self-reinforcing/self-perpetuating phenomenon.
Acheulian-style tools may have been culturally-communicated to hominins other than erectus/ ergaster. One of the most thoroughly studied sites associated with the Acheulian tradition is Gesher Benot Ya`aqov (abbreviated GBY), in northern Israel. The Acheulian tradition in the Levant is a long one, stretching from 1.5 million to 200,000 ybp. Yet, owing to the sparseness of the hominin remains recovered in the area, it is difficult to say which species of humans are associated with particular finds. It is even possible that several different types of hominins coexisted in the Levant and participated in the same tool tradition. Certainly the long temporal record of human habitation there suggests it.42
But beyond the intrinsic interest the artifacts and the various animal remains found at GBY hold for us, what they infer about human cognition is of even greater interest. Naama Goren-Inbar, who has done extensive work at GBY, cites the following indicators (among others) of human cognitive abilities the site reveals to us:
--The ability to exploit biological resources. The hominins of the GBY region were able to process the carcasses of large animals, including elephants, indicating facility with large cutting and chopping devices. They were also able to exploit marine life. Such abilities are marks of people with a specialized skill-set. These abilities were also no doubt aided by the hominins’ knowledge of the habits of regional animals and an understanding of the ecology of the area’s plant life.
--The ability to use fire (see below) and the ability to organize work spaces efficiently.
--The ability to manufacture tools efficiently. This would have involved selecting suitable kinds of stone, quarrying it if necessary, judging which techniques were most suitable for tool-making, the application of technical know-how in the actual tool-making process, and the ability to teach this know-how.
--The ability to conceptualize and plan tool manufacture. These abilities infer the possession of such capacities and skills as communication, developed working and long-term memories, spatial cognition, planning, cooperation, and effective social interaction.
--The ability to innovate and the possession of creativity.43
The Levant, of course, was also part of the pathway erectus/ ergaster groups took into southern, eastern, and southeastern Asia. In south Asia, Acheulian tools have been found in many locales in India, with more than 3,500 found at one Indian site, Attirampakkam, alone. Using a variety of dating techniques on the sediments in which these Acheulian artifacts were uncovered, scientists now estimate that there were hominins present in southern India before 1,070,000 ybp.44 In fact, the Indian subcontinent is a major repository of Acheulian tools, and some sites have as many bifacial tools as every Chinese Acheulian site combined. Many Indian sites are particularly rich in cleavers, and there is evidence of quarrying and organized manufacturing techniques. However, it is difficult to infer continuous human occupation of certain regions. In the Hunsgi-Baichbal Valley, [in southwestern India] for example, although there are almost 200 Acheulian sites, if it is assumed that humans lived in the area for 750,000 years that number of sites represents one site established (on average) about every 3,800 years. [Obviously, there may have been many sites that were contemporaneous.] It is not yet possible to judge the length of time humans inhabited specific sites. We can say that humans, including erectus, occupied many areas of the Indian subcontinent, but we have no reliable way of ascertaining their numbers.45
In China, the oldest large cutting tools have been found in the Bose basin, in the far south. The tools appear to be Acheulian in style and have been dated to about 800,000 ybp. However, there is not much evidence that the bifacial tool making in this region was of long duration. The tools may have been a technological response to extensive deforestation in the area. In general far fewer Acheulian-style tools (often called Mode 2 technology to distinguish them from simple, unifacial, Oldowan-style artifacts known as Mode 1 technology) have been found in east Asia than in south Asia, Europe, or Africa. The existence of a boundary called the Movius Line is sometimes used to explain this phenomenon. This line demarcates the regions of more sophisticated and less sophisticated stone tool manufacture. Although some critics contend that the Movius Line concept is outdated, it still appears to have utility. The researchers studying the Bose basin summarize their findings by saying,
Bose stone technology is thus compatible with Mode 2 of western Eurasia/Africa just before the early-middle Pleistocene boundary. This finding implies similar technical, cultural, and cognitive capabilities on both sides of the Movius Line. The flow of population and cultural information across the line, however, may not have been extensive.46Two researchers who have investigated the Movius Line phenomenon have noted that Acheulian-style tools in east Asia not only are less abundant but tend to be cruder, less symmetrical, and less extensively worked than those found elsewhere. They summarize the various hypotheses offered to explain this:
1. There were humans living in eastern and southeastern Asia prior to the advent of Acheulian technology.
2. The raw stone materials available to east Asian toolmakers were of low quality (a hypothesis the researchers tend to dismiss)
3. The abundance of bamboo in the region allowed east Asians to use it to perform much of the work that previously had been done by stone hand axes, causing the manufacture of bifacial stone tools to be abandoned.
4. Geographic barriers such as the Himalayas kept hominin settlement in east Asia low.
5. Hominin populations in east Asia fluctuated, hindering the process of passing on
So in considering the relative rarity of Acheulian-style tools in China, Korea, and southeastern Asia we get an idea about the limits of cultural diffusion in the world of 800,000 years ago. We see perhaps the first evidence in human life of a cultural tradition’s spread being limited by such factors as physical isolation from the mainstream of human progress.
Europe, on the other hand, had a very extensive Acheulian tradition. However, it did not extend to the entire continent. Two paleoanthropologists who have devoted extensive research to this subject point out that its heaviest concentration was in southwestern Europe, and the Acheulian tradition only got as far north as about latitude 52°N. North and east of Germany and England, evidence of hand axe industry cannot be found, with the exception of a few finds in southeastern Europe. These researchers have identified 16 significant tool sites in the Iberian Peninsula, the oldest of which that can be reliably dated being Atapuerca, Orce, Barranco León, and Fuentenueva. The Atapuerca site may indicate Acheulian-style tool-making as early as 700,000 ybp. Outside of Iberia, significant finds have been made in Italy (although they indicate the sporadic nature of early human occupation in the Italian peninsula), France (including St. Acheul, from which we get the name Acheulian, and which had its characteristic tools around 400,000 ybp), and England, where numerous hand axes have been found at a variety of sites dating from as early as 400,000 ybp.48 As we will see, Boxgrove in the UK may be the earliest English Acheulian site of them all. (And humans may have occupied part of what is now England well before that.)
The issue in regard to early human settlement in Europe is this: was the Acheulian tool culture spread there by erectus—or did a successor species bring Mode 2 technology to the western end of Eurasia? We will examine that question below.
The ability to use tools facilitates the reproductive chances of those animals that possess it. It is not sufficient, of course, by itself to guarantee such success. Tool use requires the possession of a suite of intellectual capacities. These capacities combine themselves in such a way that some humans can devise technical solutions to practical difficulties. Enough members of erectus displayed such abilities to allow it to survive in a far-flung range of environments for hundreds of thousands of years.
A major human innovation is the ability to generate fire, an ability unique in the animal kingdom. (It is important, by the way, to distinguish between the use of naturally-occurring fire and the use of deliberately-created fire. The use of fire may have preceded the ability to create fire by many millennia.) Did erectus possess this ability? Most researchers tend to be cautious about dates associated with fire use. There was at one time thought to be firm evidence of fire use at Zhoukoudian at 500,000 ybp, but a detailed analysis in the late 1990s cast doubt on this. Although the site has yielded some burned bones and other indirect evidence, no ash layers or evidence of campfires can be found.49 In 2004 evidence was published that fire was used at Gesher Benot Ya`aqov. According to the researchers studying the site, humans were making fire at GBY almost 790,000 ybp, and they have ruled out natural events, such as brushfires, as the cause of the burned specimens (mostly wood) they have recovered. They are reluctant, however, to associate this apparent fire use with a specific species.50
Fire has always been regarded as having been essential to the human settlement of the northern latitudes, but the evidence seems to indicate that the human occupation of Europe may have preceded the use of fire by hundreds of thousands of years. A recent study has found that although humans reached northern Europe some 800,000 years ago, it is virtually impossible to find evidence of fire use before 400,000 ybp. As they examine the archaeological record, researchers see a great increase in the tempo of fire use in prehistoric Europe from 400,000 to 200,000 ybp as humans mastered this ability more and more. But the remarkable fact remains: there were humans inhabiting some very harsh climates for a very long time who may have lacked the ability to make fire.51
Recent research as of this writing (2012) points to strong evidence that erectus populations in Africa controlled fire as early as 1 million ybp. The evidence comes from the Wonderwerk Cave of South Africa, which has yielded a number of Acheulian hand axes. Stratum 10 of the cave gives clear indications, through deposits of ash and charred animal bones, that the hominin occupants of the cave were engaged in an activity of enormous significance: cooking. Based on an estimate of how hot the fires these hominins used were, the fuel to make these fires was apparently brush, grasses, and leaves.52 If hominins were cooking one million years ago, this may represent the start of an activity that greatly facilitated human success. Cooking chemically alters food, not only making it more palatable but also breaking down the tough fibers of meat, making the consumption of its protein content more feasible. Cooking can also chemically alter plant-based foods as well, unlocking their nutritional potential. In effect, cooking acts as a sort of external stomach that begins the process of digestion, thus making a wider range of food available for use in the human metabolic process. Not every erectus population in the world had fire, but those that did possessed a skill of great utility.
How did erectus-like animals acquire their food? Of what did their diet consist? Certainly we must assume that foraging was an important part of erectus/ ergaster’s adaptive zone, and that this survival strategy was widely used. We assume, for example, that australopithecines were opportunistic feeders, gathering fruit and other vegetation wherever it could be had, and there is no reason to believe the earliest humans were any different. But the larger size of erectus-like humans, especially the larger brains they possessed, suggests to us that they must have, out of sheer necessity, widened the range of their diets fairly early in the existence of the species. [The evidence of animal bones at their campsites is telling on this point.] This wider diet would have, in turn, facilitated their physical growth, reinforcing their meat-consuming tendencies. A major climatic shift may have played a role in this meat-acquisition strategy. There seems to have been a significant reduction in forest and a concomitant expansion of grasslands at just about the time erectus/ ergaster was evolving and spreading.53 The effects of all these factors were hugely significant. As the authors of a study on early hominid diets have put it:
“…primary activity in early Pleistocene Africa was substantially lower than in the Pliocene, thus limiting the edible plant foods available to hominids…However, secondary (herbivore) and tertiary (carnivore) trophic-level foods likely increased in abundance; this ecological shift would have increased the over-all mammalian biomass—especially of ungulates and other large mammals—available to hominids with the technological and cognitive abilities necessary to exploit this resource…In fact, behavioral flexibility within the context of environmental variability and ecosystem heterogeneity may have served as an important selective factor in hominid encephalization.54The development of Acheulian-style tools would have greatly increased the ability of erectus/ ergaster to process animal flesh, and organized hunting would have increased the significance—and reinforced the reproductive advantage of—such social behaviors as planning, coordination of efforts, communication, division of labor, manufacture of hunting weapons, and a system for dividing the carcasses of those animals that were killed. It is possible that erectus did not hunt all of its own meat. It may have often engaged in confrontations with, and stolen the kills of, other animals which had successfully hunted game. There is also the issue of scavenging. Several researchers have hypothesized that the scavenging of carcasses by erectus was more common than hunting. Certainly, it is reasonable, in my view, to assume that the earliest humans engaged in widespread scavenging.
Yet, it instructive to observe the hunting behavior of non-human primates, specifically baboons and chimpanzees. While we must be cautious about using the behavior of our primate relatives as a model to infer behaviors in our earliest ancestors, it is still noteworthy that baboons in west Africa have been observed engaging in surprisingly sophisticated hunting, hunting that may have been a learned behavior on the part of many of its participants. Chimpanzees hunt and consume meat with regularity, and even a New World monkey, the capuchin, is an avid hunter.55 In itself, this does not prove that our ancestors were hunters. But if primates with less intelligence than erectus are capable of effective hunting, there is no reason to believe that hunting was beyond the capacity of erectus/ ergaster.
It seems likely that the first human hunters emerged before 1 million ybp. It further appears that hunting and the consumption of energy-dense, protein-rich food helped support the energy-ravenous brains that were evolving at the time. The gathering, sharing, and consumption of meat was, in all likelihood, an important social act as well, one which helped shape interaction in early human groups. Further, those who acquired large amounts of meat may have had enhanced status within the group. It is not, perhaps, too broad of a statement to say that when humans learned how to kill and consume other animals that their rise to dominance in the Animal Kingdom began.
But erectus populations may have done damage to themselves by over-dependence on certain animals. Evidence suggesting this has been found at Qesem Cave, near Tel Aviv, Israel, and GBY. And interestingly enough, this is tied to fat consumption. Primates have a need for fat. The anatomy and physiology of the intestines in great apes, aided by bacteria, allows them to synthesize fat from vegetation, but in humans, the growth of the large intestine, and thus the ability to synthesize fat, was constrained by the growth and energy demands of the brain. Therefore, consuming fat from fat-bearing food sources was the easiest way to acquire this necessity. In the Levant, erectus’s preferred fat source was the elephant Elephas antiquus, a Pleistocene-era variety. About 400,000 ybp there was a disastrous decline in the elephant population in the area. This decline may have been brought about by over-hunting. Evidence from other regions where erectus populations were found shows similar declines in the elephant population. But we cannot say with certainty that over-hunting was the primary cause of this reduction in elephant numbers. In any event, the decline in the number of elephants necessitated the increased hunting of smaller animals, which would have drastically increased the daily energy expenditure (DEE) of the erectus hunters, putting them in a negative spiral of having to kill more animals and having less bodily energy with which to do this.56 But there may have been hominins who were able to take advantage of the situation, ones smaller, more agile, and faster. As the authors of a study of this matter put it,
Our calculations show that the elephant's disappearance from the Levant just before 400 kyr was significant enough an event to have triggered the evolution of a species that was more adept, both physically and mentally, to obtain dense energy (such as fat) from a higher number of smaller, more evasive animals. The concomitant emergence of a new and innovative cultural complex –the Acheulo-Yabrudian, heralds a new set of behavioral habits including changes in hunting and sharing practices that are relevant to our model.57It is possible, therefore, that a change in the density of certain kinds of animals may have helped trigger the evolution of the humans who would ultimately replace erectus—sapiens. Obviously, much more research is needed on this line of inquiry, which remains an intriguing hypothesis rather than a universally accepted fact. But the possibility that this hypothesis is valid seems indisputable.
Meat eating appears to have had other consequences as well. Carnivores store an enormous amount of vitamin A in their livers. Consuming a carnivore’s liver can cause an agonizingly painful, even lethal condition known as vitamin A poisoning. There is evidence that the erectus specimen KNM-ER 1808, a female, suffered from this ailment. Moreover, since she survived many weeks or even months with this condition (judging by the damage to her bones), it appears that other members of her group must have cared for her, otherwise she would not have lasted more than a couple of days. Someone must have brought her water, for example, implying the existence of some sort of vessel for carrying it. More importantly, the evidence that she was cared for reveals something even more important: that 1,700,000 years ago erectus displayed sociality, a loyalty to the group’s members and a sense that the members of the group were committed to each other’s well-being. This may have been an important factor in the long survival of the species.58
Finally, did erectus possess spoken language of any kind? In its earliest phases, probably not. This conclusion rests on an analysis of the only skull of an erectus infant ever recovered, one known as the Mojokerto child, unearthed at Perning, Indonesia in the 1930s. The child was probably between six months and eighteen months of age when it died. The specimen is an almost complete calvaria. None of the child’s dentition exists, however. The specimen has been dated at 1.8 million ybp, making it one of the oldest hominins ever discovered in Indonesia. Judging from the development of various areas of the calvaria and comparing this development to that of modern humans and chimpanzees, it appears that the Mojokerto child had already attained 70% to 90% of its adult brain size. So although we only have a single skull sample here, it would seem that early Homo erectus underwent only a relatively brief period of brain development after birth, and that it is unlikely that it had the cognitive ability to use a complex spoken language.59 However, in my opinion, although the possession of spoken language in early erectus is unlikely, it is quite possible that by the time erectus-like humans attained brain sizes that overlapped with the lower end of the modern human scale that they may indeed have had the capacity for spoken communication. The question is still an open one.
Homo erectus had a long career on this planet. Its tool-making tradition, its use (in some areas, at least) of fire, its hunting tradition, and its social traditions helped establish the genus Homo in many areas of the eastern hemisphere. In some areas, particularly the Middle East, north Africa, southern Europe (perhaps), and east Africa its skills became part of the survival strategy of those who succeeded it. Erectus did not display a large capacity for technological innovation. The Acheulian toolkit retained many of its characteristic tools for hundreds of thousands of years. Nor were erectus’s numbers very great. A recent estimate made by a geneticist indicates that the entire erectus population 1.2 million ybp may have been only about 55,000.60 In contrast, a specialist in demography has recently “very roughly” estimated the erectus/ ergaster population of Eurasia and Africa prior to 300,000 ybp at between 500,000 and 700,000.61 In either case, the numbers are tiny compared to those of modern sapiens. Erectus could easily have faced extinction well before it had given rise to any successor species. On such a tenuous and fragile base did the rise of modern humans rest.
WHAT WAS THE ROLE OF HOMO HEIDELBERGENSIS IN HUMAN EVOLUTION?
The human remains we have unearthed from the mid-Pleistocene Age, the period from around 800,000 to around 200,000 ybp, have been the subject of many conflicting hypotheses over the years. However, what paleoanthropologists once called “the muddle in the middle” is slowly being clarified. Many paleoanthropologists are convinced that there was an intermediate species between erectus and sapiens. These scientists contend—although there is far from a consensus on this point—that this species, and not erectus, was the first variety of human to establish a long lineage in Europe, and that this intermediate species also had an African variant. The designation of this variety of human as a separate species is a controversial one in the eyes of some scientists, but H. heidelbergensis’ combination of erectus-like physical traits and more derived features, with a brain that was apparently fairly sophisticated, has persuaded many researchers that its role in human evolution was a crucial one.62
The first specimen attributed to H. heidelbergensis was discovered in Germany in 1907 and formally described in 1908. It was a lower jaw with dentition and an intact ramus on each side, called the Mauer mandible (named for the locale near which it was discovered). The jaw was an unusual one, fairly robust in its basic structure but possessing relatively small teeth. It has been dated to around 600,000 ybp. Since that initial discovery, a number of significant finds attributed to H. heidelbergensis have been made. Kabwe 1 (or Broken Hill), a cranium with some of the upper jaw dentition, a large face and a very large supraorbital torus, probably from an adult male, with an endocranial volume of about 1280cc, was found in Zambia and is perhaps older than 780,000 years. Bodo, a partial cranium, probably an adult male from the Middle Awash Valley in Ethiopia, with a large face, prominent supraorbital torus, and an endocranial volume of about 1250cc, is dated to 600,000 ybp. Boxgrove 1, a section of a left tibia, about 300mm in length, found at the Boxgrove archaeological site in the UK, is dated to around 500,000 ybp. Arago XXI, a skull, probably male, with a complete face and part of the cranial vault, from the mid-Pleistocene of France is dated at around 400,000 years old (but is possibly older). Apidima 2, is an almost complete skull from the Middle Pleistocene of southern Greece. (Efforts to determine a more specific date have been inconclusive.) The Petralona Cranium, also from Greece, is dated from 150,000 to 200,000 ybp.63 Cranium 5 from the Sima de los Huesos site at Atapuerca, described by Donald Johanson as “the most complete pre-modern skull in the fossil record”, has a cranial capacity of 1125cc. Cranium 4 is from the same site and has a cranial capacity of 1390cc.64 It is dated, along with Cranium 5, at greater than 300,000 years.65 And the Steinheim Skull from Germany, a mostly complete cranium with some of the upper jaw dentition, possibly an adult female, with a cranial capacity between 1100 and 1200cc, is dated to about 250,000 years.66 In the shape of various features on them, Cranium 4, Cranium 5, and the Steinheim Skull clearly exhibit certain Neanderthal-like traits.
What was H. heidelbergensis (if we accept it as a valid taxon)? There are observers who contend that it was a true multi-continent species, with African, European, and possibly Asian representatives. Certainly there are strong similarities between the European and African specimens. The most striking aspect of the species was its high level of encephalization, with an average cranial capacity of just over 1200cc compared to the average erectus size of less than 1000cc [bearing in mind, of course, that late erectus specimens were of much greater brain size than the earliest ones]. H. heidelbergensis appears to have attained a higher level of technological advances than erectus as well.67 But there are researchers who contend that what is being labeled H. heidelbergensis is simply the latter form of erectus, and that its anatomical differences are evidence of variety within erectus, and not the existence of a separate species.
Recent research has tended to bolster the status of heidelbergensis as a valid taxon, but there are still questions about which specimens deserve inclusion in it and the specific timeframe in which it evolved. A particularly intriguing specimen is known as the Ceprano calvarium, from an Italian site dated at between 430,000 and 385,000 ybp. The calvarium displays an unusual mixture of traits, some primitive, some derived. Researchers who have compared it to a wide range of African and Eurasian specimens have concluded that Ceprano, with its combination of features, may be a skull that connects Mid-Pleistocene humans from a number of different regions, in the sense that it incorporates their traits. Ceprano, in this comparative study, appears to have been the product of a dispersal of hominins that began somewhere around 780,000 years ago. It may, in fact, at 400,000 ybp, represent a bridge between erectus and heidelbergensis. The calvarium may also be a counterpart (anatomically) to the Mauer mandible.68 The Ceprano calvarium, therefore, may be a representative of the base of heidelbergensis, (which would then cause us to rethink our view of the Boxgrove, Kabwe, and Bodo specimens), or it may be a late representative of an archaic form of heidelbergensis.
There seems to be a growing consensus that the original heidelbergensis species underwent allopatric speciation (meaning speciation caused primarily by geographic isolation), producing distinct African and European lineages. [Was Ceprano, living in southern Italy, an indication of this branching?] According to this hypothesis, the European lineage produced H. neanderthalensis, a species that lasted, in various places, for more than 200,000 years. In this scenario, the African lineage produced a somewhat more successful variant. It is the African branch of H. heidelbergensis that may have given rise to Homo sapiens. In this view, heidelbergensis itself evolved out of the African form of erectus, erectus sensu lato, rather than the Asian form, erectus sensu stricto. There appear to have been, however, many subpopulations within the larger groupings (one of which, for example, has been labeled H. h. rhodesiensis) and these localized variants may have been evolutionary dead-ends. Further, the status of Homo antecessor needs clarification as well. Was it ancestral to heidelbergensis or a localized variant within it? But the picture in some ways, is becoming clearer: somewhere between 1 million and 500,000 ybp significant changes occurred in the genus Homo, ones that ultimately gave rise to modern humans, although the whole set of human phylogenetic relationships in that era has not yet, by any means, been elucidated.69 But the members of heidelbergensis that lived in east Africa may be the group from which our direct ancestors evolved.
Culturally, H. heidelbergensis seems to have outstripped the erectus populations surviving in parts of Asia. Homo heidelbergensis is associated with the oldest verified hunting weapons, four spears approximately two meters in length and sharpened at both ends, found in Germany and dated at a remarkable 400,000 ybp.70 It most definitely had command of fire, and it and its (probable) Neanderthal descendants flourished in cold regions. Perhaps most significantly, H. heidelbergensis is thought to have made one of the major breakthroughs in the history of our genus: it appears to have been the first human type to build artificial shelters, as the evidence of hut construction at Terra Amata, on the southern coast of France [within the boundaries of Nice], seems to indicate. There appears to have been a hearth among these shelters as well, and the site is dated at 350,000 to 400,000 ybp. Further evidence of shelters and hearths has been found at Bilzingsleben, Germany, also dated at around 350,000 ybp.71 Coupled with the evidence of spear-making in this general era, we can say, perhaps, that the high level of encephalization in H. heidelbergensis was beginning to manifest itself in cultural breakthroughs, breakthroughs that proved to be of tremendous utility for the survival and reproductive success of the species and its successors.
Haltingly and unevenly, pre-modern humans learned how to survive, leaving evidence in territories ranging from Ethiopia to Java, from Zambia to Korea, from Britain to Israel. It took hundreds of thousands of years for them to learn how to hack tools out of stone, use animal bones and branches to do work, use and then create fire, kill other animals and cook them, create weapons, find and then build shelters, and (presumably) clothe themselves from the hides of the animals they hunted. So readily do we speak of the time in which these things developed that we sometimes overlook the fact that when we say, for example, Homo erectus may have survived in China for about 900,000 years, we are talking about a length of time 180 times longer than all the time that has passed since the origin of the first Egyptian dynasty. The pace of change and development in the ancient human world was inconceivably slow by our standards. It took many centuries for cultural developments to be transmitted across the surface of the eastern hemisphere, carried by nomadic populations trying to make a living in diverse environments. We must assume that certain human populations had to learn virtually everything “from scratch”. Skill sets may have been lost or forgotten, and whole cultures may have disappeared because of this. How many human ways of life have been lost, forever to remain hidden from us?
Our knowledge of this world is frustratingly incomplete, resting as it does on remains that often give us only glimpses of the physical nature and life of our forebears. But one fact stands out: intelligence was their key survival skill. It was reproductively useful, and in being so, was selected. As the level of encephalization among humans increased over time, and the density and interconnectedness of the neurons in their progressively larger brains became more complex, so did their comprehension of the world, and with it, an ability to bend the world (if only in small ways) to their purposes. Physical strength and endurance were, of course, of tremendous importance in the often brutally-challenging worlds of 1,000,000 or 500,000 years ago. But the ability to assess the resources, both plant and animal, of an area, plan and organize work, interact with and communicate (in some way, if not necessarily by means of language) with the others in one’s group all rested on the possession of large, highly organized brains. It is doubtful that any human in the era prior to the evolution of modern humans had the faintest inkling of this. But it was the gelatinous tissue in their heads that was the source of all their ability to make their way through life on this tiny, insignificant planet, a world that seemed so huge and dangerous to them. They had come to possess consciousness, perhaps not a unique human trait but one so highly developed in their genus as to set it apart from all others. They probably assumed the world was exactly as their senses told them it was. Only later were humans to realize this was not the case. And did our pre-modern ancestors already imagine an unseen world of ghosts, spirits, gods, and demons? Or were these beliefs the product of brains more able to conceive of them than theirs were?
The Emergence of Homo Sapiens
We are now finally at that stage of the story where humans we would recognize as our kind are beginning to take their place in the world. Their emergence was ultimately to be of immense significance to the biosphere of the little planet, and they would eventually establish a true planet-wide culture. What kind of animals are they? Members of Homo sapiens are differentiated from other species of humans by the following basic anatomical characteristics:
--An average brain size of approximately 1300cc, [other estimates range up to 1350cc] smaller in absolute terms than Neanderthals (about whom we will say much more in the next chapter) but larger in relation to their average body size than any other kind of human.
--A skull with greater height than the skulls of previous species of humans, and one which is shorter in length (back to front) relative to its height than those of other hominins as well.
--The lack of a conspicuous brow ridge, although the very earliest members of sapiens had a more prominent supraorbital torus than we.
--A smaller face than other hominins, and a face that is completely below rather than in front of the front section of the brain. The face also has indentations below each of the eye orbits, known as the canine fossa.
--The presence of a true chin, a smaller jaw than other hominins, and smaller dentition.
--The postcranial skeleton is lighter than that of other species of humans, without the bone thicknesses displayed in many parts of the Neanderthal skeleton.72
What is perhaps the most significant trait of Homo sapiens is its highly developed prefrontal cortex, the part of the brain that deals with various “executive” functions, one that maintains much of the emotional and behavioral stability in a human, and one which is deeply important in many human cognitive functions. The human prefrontal cortex is proportionately much larger than that of the great apes. But it is not simply the size of the human prefrontal cortex that matters, it is the complexity of its internal organization. Homo sapiens may have succeeded because its prefrontal cortex’s organization was superior to anything that had ever come before it. We can infer this (perhaps) because sapiens was the first species we know of to develop symbolic communication in various forms. Further, it may have been the first species to create physical representations of objects found in the environment. The evidence is sketchy, obviously, in regard to the earlier species of humans, but so far most symbols and art objects in existence seem to be the product of sapiens’ mentality. It must also be noted that sapiens seems to have existed for many tens of thousands of years prior to producing such things.
The earliest Homo sapiens remains were found where so many other hominid remains have been unearthed, in the Omo region of Ethiopia. The remains consist of two partial crania, with some postcranial material as well. In 2008 an earlier announcement (2005) was confirmed: after a careful re-dating of remains that had been found several decades earlier, the oldest specimens of our species are approximately 195,000 years old.73 (When we consider Australopithecus afarensis, there may have been a continuous hominid occupation of Ethiopia longer than any other region on Earth.) Molecular evidence appears to indicate a divergence from the African heidelbergensis (?) population about 200,000 years ago, and this date appears to be the most likely one for the emergence of modern humans.
At about the same time sapiens was emerging, the last remnants of Homo erectus in China were dying out. There were small populations of erectus in Indonesia. In Europe, the Neanderthals were established. The climate of the Earth was mild.
Then the world began to change.
Around 195,000 years ago, the planet’s benign climate began to grow considerably colder and drier. In the northern latitudes, a period of glaciation known as Marine Isotope Stage 6 (MIS6) set in. In Africa, deserts spread and the food supply dwindled. Genetic studies indicate that the Homo sapiens breeding population (those in the potential reproductive stage of life) collapsed, from an estimated 10,000 individuals down to just a few hundred. In desperation, one of the sapiens populations migrated southward, eventually reaching the southern tip of Africa, a place we now call Pinnacle Point. There members of the group stayed, generation after generation, from about 164,000 to 35,000 years ago. (Some sapiens appear to have stayed behind in east Africa.) They developed the most advanced culture that had ever existed, learning how to harvest the abundant marine life the nearby ocean offered and eating the various tubers and bulbs (collectively known as geophytes) that grew in the region. They used fire to heat-treat stone, thereby making the fashioning of their excellent stone tools easier. Most strikingly, perhaps, there is evidence that they adorned themselves with seashells and used red ocher to draw symbols on the walls of Blombos Cave. Moreover, they taught all these skills effectively for tens of thousands of years. The conclusion is a compelling one: the Homo sapiens of Pinnacle Point were cognitively modern. They saw the world with an intelligence like ours. Not all of the community’s members stayed. As the weather became more moderate, (beginning about 123,000 years ago) apparently groups of them began moving northward again. (Some groups may have begun their migration prior to this, as there is some evidence of out-of-Africa migration as early as 125,000 ybp.) Eventually, descendants of the original refugees would radiate out of Africa and travel across first the entire eastern hemisphere, and then the entire length of the western hemisphere. The genetic evidence we have gathered leads us to an inescapable conclusion: The majority of human beings alive on this planet today may be descendants of the Homo sapiens who lived at Pinnacle Point.74 It is to the story of how Homo sapiens spread across the world’s landmasses that we will now turn.
34. Susan C. Antón, “Natural History of Homo erectus” in Yearbook of Physical Anthropology, 2003
35. “Introduction: The long journey of an ancient human ancestor” in Athena Review, Vol. 4, No.1: Homo erectus, 2004
36. Guanjun Shen, Xing Gao, Bin Gao and Darryl E. Granger, ”Age of Zhoukoudian Homo erectus determined with 26Al/10Be burial dating” in Nature 458, 198-200 (12 March 2009)
37. Xiujie Wu1, Lynne A. Schepartz, and Wu Liu, “A new Homo erectus (Zhoukoudian V) brain endocast from China” in Proceedings of the Royal Society, Biological Sciences, January 2010 vol. 277 no. 1679, 337-344
38. Eudald Carbonell, Jose´ M. Bermu´dez de Castro, Josep M. Pare´s, Alfredo Pe´rez-Gonza´lez, Gloria Cuenca-Besco´s, Andreu Olle´, Marina Mosquera, Rosa Huguet, Jan van der Made, Antonio Rosas,Robert Sala, Josep Vallverdu´, Nuria Garcı´a, Darryl E. Granger, Marı´a Martino´n-Torres, Xose´ P. Rodrı´guez, Greg M. Stock, Josep M. Verge`s, Ethel Allue´, Francesc Burjachs, Isabel Ca´ceres, Antoni Canals, Alfonso Benito, Carlos Dı´ez, Marina Lozano, Ana Mateos, Marta Navazo, Jesu´s Rodrı´guez, Jordi Rosell, and Juan L. Arsuaga, “The first hominin of Europe” in Nature, Vol. 452, 27 March 2008
39. Sileshi Semaw, Michael Rogers, and Dietrich Stout, “The Oldowan-Acheulian Transition: Is There a ‘Developed Oldowan’ Artifact Tradition?” in Sourcebook of Paleolithic Transitions: Methods, Theories, and Interpretations, edited by Marta Camps, pp. 172-187
40. Sileshi, Rogers, and Stout, pp. 187-188
41. Sileshi, Rogers, and Stout, p. 186
42. Naama Goren-Inbar, “Culture and Cognition in the Acheulian Industry: A Case Study from Gesher Benot-Ya’aqov” in Culture Evolves, edited by Andrew Whiten, Robert A. Hinde, Christopher B. Stringer, Kevin N. Laland, pp. 177-179
43. Goren-Inbar, pp. pp. 180-188
44. Jaimini Sarkar, “Presence of Early Pleistocene Acheulian hominins in South India” in Current Science, Vol. 101, No. 8, 25 October 2011.
45. Michael D. Petraglia, “The Early Paleolithic of the Indian Subcontinent: Hominin Colonization, Dispersals, and Occupation History”, in Out of Africa I: The First Hominin Colonization of Eurasia, edited by John G. Fleagle
46. Hou Yamei, Richard Potts, Yuan Baoyin, Guo Zhengtang, Alan Deino, Wang Wei, Jennifer Clark, Xie Guangmao, Huang Weiwen, “Mid-Pleistocene Acheulean-like Stone Technology of the Bose Basin, South China” in Science, 3 March 2000: Vol. 287 no. 5458 pp. 1622-1626, found here:
47. Christopher J. Norton, Stephen J. Lycett, "Movius Line," in AccessScience, ©McGraw-Hill Companies, 2010, http://www.accessscience.com
48. Manuel Santonja and Paola Villa, “The Acheulian of Western Europe” at
49. Steve Weiner, Qinqi Xu, Paul Goldberg, Jinyi Liu, and Ofer Bar-Yosef, “Evidence for the Use of Fire at Zhoukoudian, China” in Science, 10 July 1998: Vol. 281 no. 5374 pp. 251-253
50. Naama Goren-Inbar, Nira Alperson, Mordechai E. Kislev, Orit Simchoni, Yoel Melamed, Adi Ben-Nun, and Ella Werker, “Evidence of Hominin Control of Fire at Gesher Benot Ya`aqov, Israel” in Science, 30 April 2004: Vol. 304 no. 5671 pp. 725-727
51. Wil Roebroeks and Paola Villa, “On the earliest evidence for habitual use of ﬁre in Europe” in PNAS, March 29, 2011 vol. 108 no. 13 5209-5214
52. Francesco Berna, Paul Goldberg, Liora Kolska Horwitz, James Brink, Sharon Holt, Marion Bamford,and Michael Chazan, “Microstratigraphic evidence of in situ ﬁre in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa”, in PNAS, April 2, 2012
53. J. Josh Snodgrass, William R. Leonard, and Marcia R. Robertson, “The Energetics of Encephalization in Early Hominids” in The Evolution of Hominin Diets: Integrating Approaches to the Study of Palaeolithic Subsistence, edited by Jean-Jacques Hublin and Michael P. Richards, pp. 15-21
54. Snodgrass, et al, p. 21
55. Stanford, Craig Britton, The Hunting Apes: Meat Eating and the Origins of Human Behavior, pp. 27-31
56. Miki Ben-Dor, Avi Gopher, Israel Hershkovitz, Ran Barkai, “Man the Fat Hunter: The Demise of Homo erectus and the Emergence of a New Hominin Lineage in the Middle Pleistocene (ca. 400 kyr) Levant” in PLoS ONE, 6(12): e28689. doi:10.1371/journal.pone.0028689
57. Ben-Dor, et al
58. Sale, Kirkpatrick, After Eden: The Evolution of Human Domination, pp. 115-116
59. H. Coqueugniot, J.-J. Hublin, F. Veillon, F. Houe¨t, and T. Jacob, “Early brain growth in Homo erectus and implications for cognitive ability” in Nature, Vol. 431, 16 September 2004
60. Carina Storrs, “Humans Might Have Faced Extinction”, in Scientific American, March 1, 2010, located at http://www.scientificamerican.com/...
61. Jean-Noël Biraben, “The rising numbers of humankind” in Population & Societies, Number 394, October 2003
62. Katerina Harvati, “100 years of Homo heidelbergensis – life and times of a controversial taxon” in Mitteilungen der Gesellschaft für Urgeschichte — 16 (2007)
63. From Heslip, MSU, located at https://www.msu.edu/... and The Wiley-Blackwell Encyclopedia of Human Evolution, edited by Bernard Wood, pp. 35, 39, 85, 372, and 487
64. Johanson, Donald C. and Edgar, Blake, From Lucy to Language, p. 204
65. Juan-Luis Arsuaga, Ignacio Martínez, Ana Gracia, Jóse-Miguel Carretero, and Eudald Carbonell, “Three new human skulls from the Sima de los Huesos Middle Pleistocene site in Sierra de Atapuerca, Spain” in Nature, 362, 534 - 537 (08 April 1993)
66. Australian National Museum, http://australianmuseum.net.au/...
68. Aurélien Mounier, Silvana Condemi, Giorgio Manzi, “The Stem Species of Our Species: A Place for the Archaic Human Cranium from Ceprano, Italy” in PLoS One, April 20, 2011
69. Giorgio Manzi, “Before the Emergence of Homo sapiens: Overview on the Early-to-Middle Pleistocene Fossil Record (with a Proposal about Homo heidelbergensis at the subspecific level)” in International Journal of Evolutionary Biology, Volume 2011; G. Philip Rightmire, “Human Evolution in the Middle Pleistocene: The Role of Homo heidelbergensis” in Evolutionary Anthropology, Volume 6, Issue 6, pages 218–227, 1998
70. Coolidge, Frederick L., and Wynn, Thomas, The Rise of Homo Sapiens: The Evolution of Modern Thinking, p. 151
71. Ian Tattersall, “The Origins of Human Cognition and the Evolution of Rationality” in The Evolution of Rationality: Interdisciplinary Essays in Honor of J. Wentzel van Huyssteen, pp. 173-174
72. “Homo sapiens”, Institute of Human Origins, http://www.becominghuman.org/...
73. John G. Fleagle, Zelalem Assefa, Francis H. Brown, John J. Shea, “Paleoanthropology of the Kibish Formation, southern Ethiopia: Introduction” in Journal of Human Evolution, 2008.05.007
74. Curtis W. Marean, “When the Sea Saved Humanity” in Scientific American, August 2010; Brenna M. Henna, Christopher R. Gignouxb, Matthew Jobinc, Julie M. Grankae, J. M. Macpherson, Jeffrey M. Kidd, Laura Rodríguez-Botigué, Sohini Ramachandran, Lawrence Hon, Abra Brisbin, Alice A. Lin, Peter A. Underhill, David Comas, Kenneth K. Kidd, Paul J. Norman, Peter Parham, Carlos D. Bustamante, Joanna L. Mountain, and Marcus W. Feldman, “Hunter-gatherer genomic diversity suggests a southern African origin for modern humans” in PNAS, March 7, 2011