Anthropology Chapter 9

Acheulian (ash ́-oo-lay-en)

pertaining to a stone tool industry from the early and middle Pleistocene; characterized by a large proportion of bifacial tools (flaked on both sides). Acheulian tool kits are common in Africa, southwest Asia, and western Europe, but they're thought to be less common elsewhere. Also spelled Acheulean.

Who Were the earliest African emigrants?

The fossils from East Africa imply that a new adaptive pattern in human evolution appeared in Africa not long after 2 mya. Until recently, Homo erectus sites outside Africa all have reported dates that are later than the earliest finds of this species in Africa, leading paleoanthropologists to assume that the hominins who migrated to Asia and Europe descended from earlier African ancestors. Also, these travelers look like Homo, with longer limbs and bigger brains. Because H. erectus originated in East Africa, they were geographically closest to areas connected to Eurasia (through the Middle East) and thus were probably the first to leave the continent. Current evidence shows H. erectus in East Africa about 1.7 mya, while similar hominins were living in the Caucasus region of southeastern Europe even a little earlier, about 1.8 mya.* Eventually, hominins made it all the way to the island of Java, Indonesia, by 1.6 mya! It took H. erectus less than 200,000 years to travel from East Africa to Southeast Asia.

Homo erectus Stone tools

The temporal span of Homo erectus includes two different stone tool industries, one of which was probably first developed by H. erectus. Earlier finds indicate that H. erectus started out using Oldowan tool technology, which the H. erectus emigrants took with them to Dmanisi, Java, and Spain. The newer industry was invented (about 1.6 mya) after these early African emigrants left their original homeland for other parts of the Old World. This new tool kit is called the Acheulian. The important change in this kit was a core worked on both sides, called a biface (known commonly as a hand axe or cleaver) The biface had a flatter shape than seen in the rounder earlier Oldowan cores (which were worked to make quick and easy flakes and were soon discarded).

Another remarkable find from Dmanisi is the nearly complete cranium of an older adult male

and surprisingly for such an ancient find, he died with only one tooth remaining in his jaws (Lordkipanidze et al., 2006). Because his jawbones show advanced bone loss (which occurs following tooth loss), it seems that he lived for several years without being able to efficiently chew his food. As a result, it probably would have been difficult for him to maintain an adequate diet.

Three of the more important regions outside of Zhoukoudian

are Lantian County (including two sites, often simply referred to as Lantian), Yunxian County, and several discoveries in Hexian County (usually referred to as the Hexian finds

African H. erectus specimens

dated at 1.7-1 mya, and then we'll discuss those populations that emigrated to Europe and Asia.

Two badly distorted crania were discovered

in Yunxian County, Hubei Province, in 1989 and 1990 (Li and Etler, 1992). A combination of ESR and paleomagnetism dating methods =gives us an average dating estimate of 800,000-580,000 ya. If the dates are correct, this would place Yunxian at a similar age to Zhoukoudian in the Chinese sequence. Yunxian, the H. erectus inhabitants are thought to have had limited hunting capabilities, since they appear to have been restricted to the most vulnerable prey, namely, the young and old animals.

Another interpretation of the Zhoukoudian cave

wasn't open to the outside as a habitation site would be, but was accessed only through a vertical shaft. This theory has led archaeologist Alison Brooks to remark, "It wouldn't have been a shelter, it would have been a trap" (quoted in Wuethrich, 1998). These serious doubts about control of fire, coupled with the suggestive evidence of bone accumulation by carnivores, have led anthropologists Boaz and Ciochon to conclude that "Zhoukoudian cave was neither hearth nor home" (Boaz and Ciochon, 2001)

Acheulian tool culture

. Beginning with the Acheulian culture, we find the first evidence that raw materials were being transported more consistently and for longer distances. When Acheulian tool users found a suitable piece of stone, they often would take it with them as they traveled from one place to another. This behavior suggests foresight: They likely knew that they might need to use a stone tool in the future and that this chunk of rock could later prove useful. This is a major change from the Oldowan, where all stone tools are found very close to their raw-material sources. With the biface as a kind of "Acheulian Swiss army knife," these tools served to cut, scrape, pound, and dig. This most useful tool has been found in Africa, parts of Asia, and later in Europe. Note that Acheulian tool kits include several types of small tools.

the small amount in diversity lumps all pre-australopiths and australopiths as Homo

2 mya, there's less diversity among these hominins than is apparent in their pre-australopith and australopith predecessors. Consequently, there is universal agreement that the hominins found outside of Africa are all members of genus Homo. Thus, taxonomic debates focus solely on how many species are represented.

nuchal torus (nuke ́-ul) (nucha, meaning "neck")

A projection of bone in the back of the cranium where neck muscles attach. these muscles hold up the head.

European fossil hominin record

After about 400,000 ya, the European fossil hominin record becomes increasingly abundant. More fossils mean more variation, so it's not surprising that interpretations regarding the proper taxonomic assessment of many of these remains have been debated, in some cases for decades. In recent years, several of these somewhat later "premodern" specimens have been regarded either as early representatives of H. sapiens or as a separate species, one immediately preceding H. sapiens

All H. erectus shared the common features: Body Size

Anthropologists estimate that some Homo erectus adults weighed well over 100 pounds, with an average adult height of about 5 feet 6 inches (McHenry, 1992; Ruff and Walker, 1993; Walker and Leakey, 1993). Another point to keep in mind is that H. erectus was quite sexually dimorphic—at least as indicated by the East African specimens. Some adult males may have weighed considerably more than 100 pounds. Increased height, especially leg length, and weight in H. erectus are also associated with a dramatic increase in robusticity. In fact, a heavily built body was to dominate hominin evolution not just during H. erectus times, but through the long transitional era of premodern forms as well. Only with the appearance of anatomically modern H. sapiens did a more gracile skeletal structure emerge, one that still characterizes most modern populations.

How long were early hominins restricted to Africa?

Because all the early fossils have been found only in Africa, it seems that hominins were restricted to that continent for perhaps as long as 5 million years.

For many years, scientists thought that a cultural "divide" separated the Old World,

For many years, scientists thought that a cultural "divide" separated the Old World, with Acheulian technology found only in Africa, the Middle East, and parts of Europe (elsewhere, the Acheulian was presumed to be absent). But more recently reported excavations from many sites in southern China have forced reevaluation of this hypothesis (Hou et al., 2000). The archaeological assemblages from southern China are securely dated at about 800,000 ya and contain numerous bifaces, very similar to contemporaneous Acheulian bifaces from Africa. New evidence from India dates the Acheulian in southern Asia to at least 1 mya (Pappu et al., 2011). It now appears likely that cultural traditions relating to stone tool technology were largely equivalent over the full geographical range of H. erectus and its contemporaries. Evidence of butchering is widespread at H. erectus sites, and in the past, such evidence has been cited in arguments for consistent hunting (researchers formerly interpreted any association of bones and tools as evidence of hunting). But many studies now suggest that cut marks on bones from the H. erectus time period often overlay carnivore tooth marks. This means that hominins weren't necessarily hunting large animals but were scavenging meat and bone marrow from animals killed by carnivores. It's also crucial to mention that they obtained a large amount of their daily calories from gathering wild plants, tubers, and fruits. Like hunter-gatherers of modern times, H. erectus individuals were most likely consuming most of their daily calories from plant material

Gran Dolina site

Gran Dolina is a later site, and based on specialized techniques it's dated to approximately 850,000-780,000 ya (Parés and Pérez- González, 1995; Falguères et al., 1999

When did Homo Erectus live?

Homo erectus populations lived in very different environments over much of the Old World.

In 1980 and 1981 discoveries

In 1980 and 1981, the remains of several individuals, all bearing some resemblance to similar fossils from Zhoukoudian, were recovered from Hexian County, in southern China (Wu and Poirier, 1995; b. A close relationship has been postulated between the H. erectus specimens from the Hexian finds and from Zhoukoudian (Wu and Dong, 1985). Dating of the Hexian remains is unclear, but they appear to be later than Zhoukoudian, perhaps by several hundred thousand years.

evidence of the use of fire by hominins during the Pleistocene

More recent (and convincing) evidence of the use of fire by hominins during the Pleistocene comes from Wonderwerk Cave, in South Africa, dated to 1 mya. Evidence of cooking includes ash deposits and burned bones found in association with Acheulian tools (Berna et al., 2012). What's more, these deposits were located 30 m within the cave, ruling out lightning as the source of the fire. These findings suggest that hominins were adept at cooking and using fire much earlier than previously thought. Debates on the earliest evidence for the use of fire will likely continue. As analytical methods progress, we will have a better understanding of the timing and geographical distribution of this cultural behavior and its implications for the human diet

Cultural Remains from Zhoukoudian

More than 100,000 artifacts have been recovered from this vast site, which was occupied intermittently for many thousands of years. The earliest tools are generally crude and shapeless, but they become more refined over time. Common artifacts at the site are referred to as choppers and chopping tools, but retouched flakes were fashioned into scrapers, points, burins, and awls

Lantian site

Originally dated to 1.15 mya, Lantian is older than the fossils at Zhoukoudian (Zhu et al., 2003). However, the site was recently redated to between 1.65 and 1.54 mya (Zhu et al., 2015), indicating it is substantially older than originally thought. From the Lantian sites, the cranial remains of two adult H. erectus females have been found in association with fire-treated pebbles and flakes as well as ash (Woo, 1966; ). One of the specimens, an almost complete mandible containing several teeth, is quite similar to those from Zhoukoudian.

Other important H. erectus finds discovered by Louis Leakey

Other important H. erectus finds have come from Olduvai Gorge, in Tanzania. These fossils include a very robust skull discovered by Louis Leakey in 1960. The skull, dated to 1.4 mya, has a well-preserved cranial vault with just a small part of the upper face. Estimated at 1,067 cm3, the cranial capacity is the largest of all the African H. erectus specimens. The browridge is massive, the largest known for any hominin, but the walls of the cranial vault are thin. This latter characteristic is seen in most East African H. erectus specimens; in this respect, they differ from Asian H. erectus, in which cranial vault bones are thick.

Fire use of the Zhoukoudian

Probably the most intriguing archaeological aspect of the presumed hominin behavior at Zhoukoudian has been the long-held assumption that H. erectus deliberately used fire inside the cave. Controlling fire was one of the major cultural breakthroughs in prehistory. By providing warmth, a means of cooking, light to further modify tools, and protection, controlled fire would have been a giant technological innovation. Though some potential early African sites have yielded evidence that to some have suggested hominin control of fire, it's long been assumed that the first definite evidence of hominin fire use comes from Zhoukoudian. Now even this assumption has been challenged. In the course of further excavations at Zhoukoudian during the 1990s, researchers carefully collected and analyzed soil samples for distinctive chemical signatures that would show whether fire had been present in the cave (Weiner et al., 1998). They determined that burned bone was only rarely found in association with tool. In most cases, the burning appeared to have taken place after fossilization—that is, the bones weren't cooked while fresh. In fact, it turns out that the "ash" layers aren't actually ash, but naturally accumulated organic sediment. This last conclusion was derived from chemical testing that showed absolutely no sign of wood having been burned inside the cave.

stone tools at Dmaisi

Researchers have also recovered some stone tools at Dmanisi. The tools are similar to the Oldowan industry from Africa, as would be expected for a site dated earlier than the beginning of the Acheulian industry; this later and very important tool industry is first found associated with African H. erectus after 1.6 mya

The Homo erectus remains from East Africa show several differences from the Javanese and Chinese fossils.

Some African cranial specimens—particularly ER 3733, presumably a female, and WT 15000, presumably a male—aren't as strongly buttressed at the browridge and nuchal torus, and their cranial bones aren't as thick. Indeed, some researchers are so impressed by these differences, as well as others in the postcranial skeleton, that they're arguing for a separate species status for the African material, to distinguish it from the Asian samples. Bernard Wood, a leading proponent of this view, has suggested that the name Homo ergaster be used for the African remains and that H. erectus be reserved solely for the Asian material (Wood, 1991). In addition, the very early dates now postulated for the dispersal of H. erectus into Asia (Java) would argue that the Asian and African populations were separate (distinct) for more than 1 million years. As a result of the discovery of the Daka cranium in Ethiopia and continued comparison of these specimens, this species division has not been fully accepted; the current consensus (and the one we prefer) is to continue referring to all these hominins as Homo erectus (Kramer, 1993; Conroy, 1997; Rightmire, 1998; Asfaw et al., 2002). So, as with some earlier hominins, our interpretation of H. erectus requires us to recognize a considerable degree of variation within this species.

most recent evidence from Dmanisi

Some of the most recent evidence from Dmanisi includes several postcranial bones coming from at least five individuals (Lordkipanidze et al., 2007, 2013). This new evidence is especially important because it allows us to make comparisons with what is known of H. erectus from other areas. The Dmanisi fossils have an unusual combination of traits. They weren't especially tall, having an estimated height ranging from about 4 feet 9 inches to 5 feet 5 inches. Certainly, based on this evidence, they seem much smaller than the full H. erectus specimens from East Africa or Asia. Yet, although very short in stature, they still show body proportions (such as leg length) like that of H. erectus (and H. sapiens) and quite different from that seen in earlier hominin

How can he Asian crania from Java and China be explained H. erectus migration?

The Asian crania from Java and China share many similar features, which could be explained by H. erectus migration from Java to China perhaps as early as 1.6 mya (based on the new dates from Lantian). Asia has a much longer H. erectus habitation than Africa (1.8 mya-40,000 or 70,000 ya versus 1.7-1 mya), and it's important to understand the variation seen in this geographically dispersed species

Atapuerca site

The earliest find from Atapuerca (from Sima del Elefante) has been recently discovered and dates to 1.2 mya, making it clearly the oldest hominin yet found in western Europe (Carbonell et al., 2008). So far, just one specimen has been found here, a partial jaw with a few teeth. Very provisional analysis suggests that it most closely resembles the Dmanisi fossils. There are also tools and animal bones from the site. As at the Dmanisi site, the implements are simple flake tools similar to that of the Oldowan. Some of the animal bones found at the site also bear the scars of hominin activity, with cut marks indicating the butchering of animal carcasses

Chinese H. erectus

The hominin remains belong to upward of 40 adults and children and together provide a good overall picture of Chinese H. erectus. Like the materials from Java, they have typical H. erectus features, including a large browridge and nuchal torus. Also, the skull has thick bones, a sagittal keel, and a protruding face and is broadest near the bottom. This site, along with others in China, has been difficult to date accurately. Although Zhoukoudian was previously dated to about 500,000 ya, a new radiometric dating technique that measures isotopes of aluminum and beryllium shows that Zhoukoudian is actually considerably older, with a dating estimate of approximately 780,000 ya (Ciochon and Bettis, 2009; Shen et al., 2009)

The later, more widely dispersed hominins were quite different

The later, more widely dispersed hominins were quite different both anatomically and behaviorally from their African ancestors. They were much larger, were more committed to a completely terrestrial habitat, used more elaborate stone tools, and probably ate meat.

D4500

The most recently reported specimen, discovered in 2005, is a complete skull, indeed the most complete skull of early Homo (Lordkipanidze et al., 2013). The cranium, known as D4500 , fits perfectly with a mandible discovered a decade earlier (D2600). This skull shows several primitive traits, including a small cranial vault and a massive, prognathic face. In fact, this skull has the smallest cranial capacity of all Dmanisi finds (~550 cm3). This specimen is especially important because of its completeness and lack of distortion, providing a clear idea of what it looked like and exactly how the face and vault fit together. Lordkipanidze and colleagues (2013) hypothesize that the skull may be associated with postcranial materials found at the site, which suggests similar body proportions as found in modern humans.

The significant finds of H. Erectus

The most significant H. erectus fossil from East Turkana is a nearly complete skull (ER 3733;). Recently redated at 1.7 mya, this fossil is about the same age (or even just a little younger) than some other fossils outside of Africa; nevertheless, for now, it certainly is the oldest known member of this species from Africa (Lepre and Kent, 2010). The cranial capacity is estimated at 848 cm3, in the lower range for H. erectus (700 to 1,250 cm3), which isn't surprising considering its early date. A second very significant new find from East Turkana is notable because it has the smallest cranium of any H. erectus specimen from anywhere in Africa. Dated to around 1.5 mya, the skull has a cranial capacity of only 691 cm3. there are a couple of crania from southeastern Europe that are even smaller. The small skull from East Turkana also shows more gracile features (such as smaller browridges) than do other East African H. erectus individuals, but it preserves the overall H. erectus vault shape. It's been proposed that perhaps this new find is a female and that the variation indicates a very high degree of sexual dimorphism in this species (Spoor et al., 2007).

Zhoukoudian

The story of the first discoveries of Chinese Homo erectu. Europeans had known for a long time that "dragon bones," used by the Chinese as medicine and aphrodisiacs, were actually ancient mammal bones. Scientists eventually located one of the sources of these bones near Beijing at a site called Zhoukoudian (sometimes spelled Choukoutien). Major excavations were undertaken in the 1920s, and in 1929, a fossil skull was discovered. The skull turned out to be a juvenile's, and although it was thick, low, and relatively small, there was no doubt that it belonged to an early hominin

Later Homo erectus from Europe

Though not as old as the Dmanisi material, fossils from the Atapuerca region in northern Spain are significantly extending the antiquity of hominins in western Europe. There are several caves in the Atapuerca region, two of which (Sima del Elefante and Gran Dolina) have yielded hominin fossils contemporaneous with H. erectus. At this point, however, there is little agreement on the taxonomic status of these fossils from western Europe (Antón, 2013).

Pleistocene

the epoch of the Cenozoic from 1.8 mya until 10,000 mya. Frequently referred to as the ice Age, this epoch is associated with continental glaciations in northern latitudes.

Three other sites from Ethiopia have yielded H. erectus fossils

the most noteworthy coming from the Gona area and the Daka locale, both in the Awash River region of eastern Africa (Gilbert and Asfaw, 2008).

Homo erectus

"Upright man." A species within the genus Homo first appearing just after 1.7 million years ago in Africa and ultimately spreading throughout the Old World. The species for which we have the most evidence. the one group that most paleoanthropologists have recognized for decades and still agree on. Discovery began in the nineteenth century.

recent discovery from the Middle Awash of Ethiopia

Another recent discovery from the Middle Awash of Ethiopia of a mostly complete cranium from Daka is also important because this individual (dated at approximately 1 mya) is more like Asian H. erectus than are most of the earlier East African remains we've discussed (Asfaw et al., 2002; Gilbert and Asfaw, 2008). Consequently, the suggestion by several researchers that East African fossils are a different species from (Asian) H. erectus isn't supported by the morphology of the Daka cranium. In fact, a cladistics analysis of traits found in H. erectus crania was unable to identify meaningful regional variation, supporting a single-species argument (Asfaw et al., 2002; Gilbert et al., 2003; Gilbert, 2008).

Kamoya Kimeu research

Another remarkable discovery was made in 1984 by Kamoya Kimeu, a member of Richard Leakey's team known widely as an outstanding fossil hunter. Kimeu discovered a small piece of skull on the west side of Lake Turkana at a site known as Nariokotome. Excavations produced the most complete H. erectus skeleton ever found. Known formally as WT 15000, the almost complete skeleton includes facial bones, a pelvis, and most of the limb bones, ribs, and vertebrae and is chronometrically dated to about 1.6 mya (Walker and Leakey, 1993)

discovery from the Ceprano Site (European Discovery)

Finally, the southern European discovery of a well- preserved cranium from the Ceprano site in central Italy may be the best evidence yet of H. erectus in Europe (Ascenzi et al., 1996). Provisional dating suggested a date between 900,000 and 800,000 ya , but more recent paleomagnetic studies have indicated a date of 450,000 ya (Muttoni et al., 2009). Philip Rightmire (1998) has concluded that cranial morphology places this specimen quite close to H. erectus. Italian researchers have proposed a different interpretation that classifies the Ceprano hominin as a species separate from H. erectus. For the moment, the exact relationship of the Ceprano find to H. erectus remains to be fully determined

All H. erectus shared the common features: Cranial Size

Homo erectus crania display a highly distinctive shape, partly because of increased brain size, but probably more correlated with increased body size. The ramifications of this heavily built cranium are reflected in thick cranial bone (in most specimens), large browridges (supraorbital tori) above the eyes, and a projecting nuchal torus at the back of the skull. The braincase is long and low, receding from the large browridges with little forehead development. Also, the cranium is wider at the base compared with earlier and later species of genus Homo. The maximum breadth of the cranium is located below the ear canal, giving the cranium a pentagonal shape when viewed from behind. In contrast, the skulls of early Homo and H. sapiens have more vertical sides, and the maximum width is above the ear canal. Most specimens also have a sagittal keel running along the midline of the skull. Very different from a sagittal crest, the keel is a small ridge that runs front to back along the sagittal suture (shaped like a keel on the bottom of a boat). The sagittal keel, browridges, and nuchal torus don't seem to have served an obvious adaptive function, but most likely reflect bone buttressing in a very robust s

Summary of Main Topics

* Homo erectus remains have been found in Africa, Europe, and Asia dating from about 1.8 mya to at least 100,000 ya-and probably even later-and thus this species spanned a period of more than 1.5 million years. * H. erectus likely first appeared in East Africa and later migrated to other areas. This widespread and highly successful hominin defines a new and more modern and grade of human evolution. *H. erectus differs from early Homo, with its larger brain, taller stature, robust build, and changes in facial structure and cranial buttressing. *H.erectus and contemporaries introduced more sophisticated tools (as part of the Acheulian industry) and probably ate novel foods processed in new ways, including meat as a major source of protein. By using these new tools—and at later sites possibly fire as well—they were also able to move into different environments and successfully adapt to new conditions. *

Female Skeleton of the H. erectus

A recently discovered nearly complete female H. erectus pelvis comes from the Gona area in Ethiopia and is dated to approximately 1.3 mya (Simpson et al., 2008). This find is particularly interesting because H. erectus postcranial remains are so rare, and this is the first H. erectus female pelvis yet found. This new pelvis is very different from that of the Nariokotome pelvis and may reflect considerable sexual dimorphism in skeletal anatomy linked to reproduction as well as body size. This fossil also reveals some tantalizing glimpses of likely H. erectus growth and development. The pelvis has a very wide birth canal, indicating that quite large-brained infants could have developed in utero (before birth); in fact, it's possible that an H. erectus newborn could have had a brain that was almost as large as what's typical for modern human babies This evidence has led Scott Simpson and his colleagues to suggest that H. erectus prenatal brain growth was more like that of later humans and quite different from that found in apes or in australopiths such as Lucy. However, it's also evident that H. erectus brain growth after birth was more rapid than in modern humans

Dmanisi

A site in the Republic of Georgia, has produced several individuals, giving us a unique look at these first possible travelers. The age of this crucial site has recently been radiometrically dated to 1.81 mya (Garcia et al., 2010). The Dmanisi crania are similar to those of H. erectus (for example, the long, lowbraincase, wide base, and sagittal keeling) However, other characteristics of the Dmanisi individuals are different from other hominins outside Africa. In particular, one of the most complete fossils (specimen 2700) has a less robust and thinner browridge, a projecting lower face, and a relatively large upper canine. At least when viewed from the front, this skull is more reminiscent of the smaller early Homo specimens from East Africa than it is of H. erectus. Also, specimen 2700's cranial capacity is very small—estimated at only 600 cm3, well within the range of early Homo. In fact, all four Dmanisi crania so far described have relatively small cranial capacities—the other four estimated at 550 cm3, 630 cm3, 650 cm3, and 780 cm3.

All of these early hominins were restricted to

Africa.

debates after the publication of On the Origin of Species,

After the publication of On the Origin of Species, debates about evolution were prevalent throughout Europe. While many theorists simply stayed home and debated the merits of natural selection and the likely course of human evolution, one young Dutch anatomist decided to go find evidence of it. Eugene Dubois (1858-1940) enlisted in the Dutch East Indian Army and was shipped to the island of Sumatra, Indonesia, to look for what he called "the missing link. In October 1891, after moving his search to the neighboring island of Java, Dubois' field crew unearthed a skullcap along the Solo River near the town of Trinil—a fossil that was to become internationally famous as the first recognized human ancestor ). The following year, a human femur was recovered about 15 yards upstream in what Dubois claimed was the same level as the skullcap, and he assumed that the skullcap (with a cranial capacity of slightly over 900 cm3) and the femur belonged to the same individual

All H. erectus shared the common features: Brain size

Although Homo erectus differs in several respects from both early Homo (for example, Homo habilis) and Homo sapiens, the most obvious feature is the internal cranial size—which is closely related to brain size. Early Homo had cranial capacities ranging from as small as 500 cm3 to as large as 800 cm3. H. erectus, on the other hand, shows considerable brain enlargement, with a cranial capacity of about 700* to 1,250 cm3 (and a mean of approximately 900 cm3). H. erectus was also considerably larger than earlier members of the genus Homo. In fact, when we compare H. erectus with the larger-bodied early Homo individuals, relative brain size is about the same (Walker, 1991). What's more, when we compare the relative brain size of H. erectus with that of H. sapiens, we see that H. erectus was considerably less encephalized than later members of the genus Homo

the most variation is seen

Among these four crania from one locality we see more variation than between the African and Asian forms, which many researchers have interpreted as different species. Also, the new discovery from Daka (Ethiopia) of a young African specimen with Asian traits further weakens the separate-species interpretation of H. ergaster

The H.erectus was the first to leave Africa

Based on the evidence from Dmanisi, we can assume that Homo erectus was the first hominin to leave Africa. Although the Dmanisi specimens are small in both stature and cranial capacity, they have specific characteristics that identify them as H. erectus (for example, a sagittal keel and low braincase). So, for now, the Dmanisi hominins are thought to be H. erectus, although an early and quite different variety from that found almost anywhere else. Though new and thus tentative, the recent evidence raises important and exciting possibilities. The Dmanisi findings suggest that the first hominins to leave Africa were quite possibly a small-bodied very early form of H. erectus, possessing smaller brains than later H. erectus and carrying with them a typical African Oldowan stone tool culture Also, the Dmanisi hominins had none of the adaptations hypothesized to be essential to hominin migration—that is, being tall and having relatively large brains. Another explanation may be that there were two migrations out of Africa at this time: one consisting of the small-brained, short-statured Dmanisi hominins and an almost immediate second migration that founded the well-recognized H. erectus populations of Java and China. All this evidence is so new, however, that it's too soon even to predict what further revisions may be required

Homo antecessor

Because all the remains so far identified from both these caves at Atapuerca are fragmentary, assigning these fossils to particular species poses something of a problem. Spanish paleoanthropologists who have studied the Atapuerca fossils have decided to place these hominins into another (separate) species, one they call Homo antecessor (Bermúdez de Castro et al., 1997; Arsuaga et al., 1999). However, it remains to be seen whether this newly proposed species will prove to be distinct from other species of Homo

Homo erectus difference from African Predecessors

Most analyses show that H. erectus is quite different from its more ancient African predecessors. Increase in body size and robustness, changes in limb proportions (especially longer lower limbs), and an increase in brain size (that is, greater encephalization) all indicate that these hominins were more like modern humans in their adaptive pattern than their African ancestors were. It's clear from most of the fossils usually classified as Homo erectus that a major adaptive shift had taken place—one setting hominin evolution in a distinctly more human direction.

Where did Homo erectus first appear?

Most likely, this species initially evolved in Africa. Two important pieces of evidence help support this hypothesis. First, all of the earlier hominins prior to the appearance of H. erectus come from Africa. What's more, by 1.7 mya, there are well-dated fossils of this species at East Turkana, in Kenya, and not long after that at other sites in East Africa

seeing the Connections: interpretations of Homo erectus

Several aspects of the geographical, physical, and behavioral patterns shown by Homo erectus seem clear. But new discoveries and more in-depth analyses are helping us to reevaluate our prior ideas. The fascinating fossil hominins discovered at Dmanisi are perhaps the most challenging piece of this puzzle. Past theories suggested that H. erectus was able to emigrate from Africa owing to more advanced tools and a more modern anatomy (longer legs, larger brains) compared with earlier African hominins. Yet, the Dmanisi cranial remains show that these very early Europeans still had small brains; and H. erectus in Dmanisi, Java, and Spain was still using Oldowan-style tools. So it seems that some key parts of earlier hypotheses are not fully accurate. At least some of the earliest emigrants from Africa didn't yet show the entire suite of H. erectus physical and behavioral traits. How different the Dmanisi hominins are from the full H. erectus pattern remains to be seen, and the discovery of more complete postcranial remains will be most illuminating. Going a step further, the four crania from Dmanisi are extremely variable; one of them, in fact, does look more like H. erectus. It would be tempting to conclude that more than one type of hominin is represented here, but they're all found in the same geological context. The archaeologists who excavated the site conclude that all the fossils are closely associated with each other. The simplest hypothesis is that they're all members of the same species. This degree of apparent intraspecific variation is biologically noteworthy, and it's influencing how paleoanthropologists interpret all of these fossil samples.

Ngandong site

The fossils from the Ngandong site are by far the most recent group of H. erectus fossils from Java or anywhere else. At Ngandong, an excavation along an ancient river terrace produced 11 mostly complete hominin skulls. Some estimates of the age of the Ngandong H. erectus fossils initially suggested an age of only 50,000- 25,000 years ago (ya). These dates are quite controversial, and further evidence has established a very late survival of H. erectus in Java (approximately 70,000-40,000 ya) (Yokoyama et al., 2008). So these individuals would be contemporary with H. sapiens—which, by this time, had expanded widely throughout the Old World and into Australia around 60,000-40,000 ya. Recent work on the old excavation site of Ngandong (first excavated in the early 1930s) has led to a rediscovery of the fossil bed where the 14 individuals had been found (Ciochon et al., 2009). New dating techniques and fossil identification will be undertaken to better understand site formation processes and taphonomy. hominins have been found not far away, apparently evolving while isolated on another Indonesian island.

Zhoukoudian Homo erectus

discovered in the 1920s and 1930s. ), are by far the largest collection of H. erectus material found anywhere. This excellent sample includes 14 skullcaps other cranial pieces, and more than 100 isolated teeth, but only a scattering of postcranial elements (Jia and Huang, 1990). Various interpretations to account for this unusual pattern of preservation have been offered, ranging from ritualistic treatment or cannibalism to the more mundane suggestion that the H. erectus remains are simply the leftovers of the meals of giant hyenas. The hominin remains were studied, and casts were made immediately, which proved invaluable, because the original specimens went missing during the American evacuation of China at the start of World War II.

The earliest of the East African H. erectus fossils come

from East Turkana, from the same area where earlier australopith and early Homo fossils have been found .Indeed, it seems likely that in East Africa around 2-1.8 mya, some form of early Homo evolved into H. erectus

Boaz and Ciochon (2001)

have suggested that much of the material in the cave likely accumulated through the activities of extinct giant hyenas. In fact, they hypothesize that most of the H. erectus remains, too, are the leftovers of hyena meals. Boaz and his colleagues do recognize that the tools in the cave, and possibly the cut marks on some of the animal bones, provide some insight on hominin activities at Zhoukoudian

Counting the initial find plus later discoveries, so far all the Homo erectus fossil remains have come from

six sites located in eastern Java. The dating of these fossils has been hampered by the complex nature of Javanese geology, but it's generally accepted that most of the fossils belong to the Early to Middle Pleistocene and are between 1.6 and 1 million years old. What's more, there was also a very late surviving H. erectus group in Java that apparently managed to survive there until less than 100,000 years ago, and possibly as recent as 25,000 years ago.

The way of life at Zhoukoudian + diet

that of hunter-gatherers who killed deer, horses, and other animals. Fragments of charred ostrich eggshells and abundant deposits of hackberry seeds unearthed in the cave suggest that these hominins supplemented their diet of meat by gathering herbs, wild fruits, tubers, and eggs. Layers of what has long been thought to be ash in the cave (over 18 feet deep at one point) have been interpreted as indicating the use of fire by H. erectus In the 1980s, several researchers have challenged this picture of Zhoukoudian life. Lewis Binford and colleagues (Binford and Ho, 1985; Binford and Stone, 1986a, 1986b) reject the description of H. erectus as hunters and instead argue that the evidence clearly points more accurately to scavenging.

"nariokotome boy"

the most complete H. erectus specimen yet found. The skeleton is that of a juvenile about 8 years of age with an estimated height of about 5 feet 3 inches (Walker and Leakey, 1993; Dean and Smith, 2009). Some estimates have hypothesized that the adult height of this individual could have been about 6 feet. A recent reexamination of the Nariokotome skeleton's growth and development pattern generated hypothetical growth curves based on modified growth curves for both humans and chimpanzees (Graves et al., 2010). By estimating how much growth remained at the time of death, the researchers suggested that maximum height would have been completed by around 12 years of age; thus, their revised stature estimate suggests an adult height of between 5 feet and 5 feet 7 inches (mean of 5 feet 4 inches). The cranial capacity of WT 15000 is estimated at 880 cm3; brain growth was nearly complete, and the adult cranial capacity would have been approximately 909 cm3 (Begun and Walker, 1993; Falk, 2012). Based on size and the degree of robusticity, many researchers argue that the skeleton is male.

European fossils from Spain

the separate-species status of the early European fossils from Spain (Sima del Elefante and Gran Dolina) is also not yet clearly established. We still don't have much good fossil evidence from these two sites; but dates going back to 1.2 mya for the earlier site are well confirmed. Recall also that no other western European hominin fossils are known until at least 500,000 years later, and it remains to be seen if any of these European hominins dating prior to 500,000 ya are ancestors of any later hominin species. Nevertheless, it's quite apparent that later in the Pleistocene, well- established hominin populations were widely dispersed in both Africa and Europe. These later premodern humans are the topic of the next chapter. When looking back at the evolution of H. erectus, we realize how significant this early human was. H. erectus had greater limb length and thus more efficient bipedalism; was the first species with a cranial capacity approaching the range of H. sapiens; became a more efficient scavenger and exploited a wider range of nutrients, including meat; and ranged across the Old World, from Spain to Indonesia. In short, it was H. erectus that transformed hominin evolution to human evolution. As Richard Foley states, "The appearance and expansion of H. erectus represented a major change in adaptive strategy that influenced the subsequent process and pattern of human evolution" (1991)