ANTHR-1

CHAPTER 9 The Earliest Dispersal of the Genus Homo:

Homo erectus and Contemporaries

First Dispersal of the Hominins

• Close to 2 million years ago, hominins expanded out of Africa into other areas

of the Old World.

• Early hominin fossils have never been discovered out of Africa, leading

researchers to believe that the early hominins were isolated there for 5 million

years.

• After 2 mya, there’s less diversity in these hominins than in their pre-

australopith and australopith predecessors.

• There is some variation among the different geographical groups of these

hominins, and anthropologists still debate how to classify them.

• There is universal agreement that the hominins found outside of Africa are

members of genus Homo.

Homo erectus • The first hominin to expand into new regions of the Old

World.

• Homo erectus is the hominin species for which there is the

most evidence.

• As a species, H. erectus existed over 1 million years.

• More evolved behavioral/cultural practices and larger more

derived bodies aided their success

• East African finds have been dated to 1.7 m.y.a.

Lumping vs Splitting

• Depending on preference researchers tend to want to group individual fossil finds together into species (lumping) or split a genus into as many identifiable species as possible (spliting)

• Some researchers split Homo erectus into two species • African fossils into Homo ergaster.

• Asian fossils into Homo erectus

• Analyses show that H. erectus/ergaster are a closely related species and possibly geographical varieties of a single species

Morphology of Homo erectus

• There was much varition in the individual groups that are

included in H. erectus, but they share a set of features:

Body Size

• Adult weight >100 lbs, average adult height of ca. 5 feet 6

inches

• Sexually dimorphic, weight and height varied according to

sex

• Increased robusticity (heavily built body) that dominated

hominin evolution until anatomically modern H. sapiens

Brain Size

• Cranial capacities 700 cm3 to 1250 cm3

• Brain size closely linked with overall body size

• H. erectus is larger-bodied than early Homo sample but relative brain size is about the same

• Relative brain size of H. erectus is considerably less encephalized than later members of genus Homo

Cranial Shape • Thick cranial bone, large brow ridges (supraorbital tori), and projecting

nuchal torus

• A projection of bone in the back of the cranium where neck muscles attach;

used to hold up the head.

• Braincase long and low, with little forehead development

• Cranium wider at base, compared with earlier and later species

• Sagittal keel, a small ridge from front to back along the sagittal suture

African Origin of H. erectus • African origin supported by evidence of:

1. Earlier hominins prior to the appearance of H. erectus occurring in

Africa.

2. 1.7 mya fossils at East Turkana, in Kenya, where australopiths have

also been found,and not long after at other sites in East Africa.

3. Though, 1.8 mya populations in southeastern Europe; 1.6 mya

populations in Indonesia, suggesting quick migrations

4. It seems likely that in East Africa around 2.0 –1.8 mya, some form of

early Homo evolved into H. erectus.

Nariokotome Skeleton WT 15000:

Turkana Boy

• In 1984, Kamoya Kimeu discovered a small piece

of skull on the west side of Lake Turkana at the

site known as Nariokotome.

• The excavations produced the most complete H.

erectus skeleton ever found

• Facial bones, a pelvis, and most of the limb

bones, ribs, and vertebrae.

Nariokotome Skeleton

• The Nariokotome

skeleton is dated to

about 1.6 mya.

• The skeleton is that of

a boy about 8 to 12

years of age with an

estimated height of 5

feet 3 inches.

Other Important African Finds • Olduvai Gorge, dated at 1.4 mya :

• Cranial vault with small part of upper face, the cranial capacity is

the largest of all the African H. erectus specimens.

• The browridge is the largest known for any hominin, but the walls of

the braincase are thin. Similar to East African H. erectus specimens;

differs from thick cranial bones in Asian H. erectus.

• Gona, Ethiopia dated to appx. 1.3 mya

• Female pelvis with very wide birth canal, indicating large-brained

infants in utero, perhaps newborn H. erectus had a brain similar to

modern human baby

• When compared with Nariokotome pelvis, considerable sexual

dimorphism in skeletal anatomy is linked to reproduction and body

size

Other Important African Finds

• Daka, Middle Awash of Ethiopia find dated to appx. 1

mya

• Complete cranium more like Asian H. erectus than most

earlier East African remains discussed

• Discounts argument that East African fossils are

different species than Asian H. erectus

The First Hominins to Leave Africa

• Evolved in Africa about 2.0 mya

• Once spread into new environments outside of Africa a

great range of physical variation in specimens begins to

be seen at about 1.8 mya

• Reached Java, Indonesia by 1.6 mya

• Equates to less than 200,000 years to travel from East

Africa to Southeast Asia

The Dmanisi Hominins • The remains are the best-preserved hominins of this age found anywhere outside of Africa.

• 1.8 mya

• All three Dmanisi crania have small cranial capacities.

• A number of stone tools, similar to Olduwan industry from Africa, have been recovered at Dmanisi.

• Remains from four individuals allows comparisons with H. erectus from other areas

Diagnostic Characteristics

• The most complete specimen has a less robust and

thinner browridge, a projecting lower face, and a large

upper canine.

• Estimated height ranging from ca 4 feet 9 inches to 5 feet

5 inches, smaller than full H. erectus specimens from East

Africa or Asia

• Body proportions, however, similar to H. erectus (and H.

sapiens) and different from earlier hominins

Possibilities Raised by the Dmansi Discoveries

1. First hominins to leave Africa were small-bodied early form of

H. erectus, with smaller brains than later forms and carrying

a typical African Oldowan stone tool culture

2. Perhaps two migrations out of Africa at the time: small-

brained, short-statured Dmanisi hominins and large, robust

body build of H. erectus populations of Java and China

Does this skull represent care for the elderly?

Homo Erectus from Indonesia

• Six sites in eastern Java, dating from 1.6 mya to 1 mya, during the Early to Middle Pleistocene.

• The Ngandong individuals date from 27,000 ya. • Excavated in 1930, being re-dated believed possibly 40-70,000 ya

• The famous Trinil skullcap found by Eugene Dubois in Java.

Zhoukoudian Homo erectus

• 40 male and female adults and children near Beijing, at Zhoukoudian, excavated beginning in 1920s.

• 14 skullcaps, other cranial pieces, more than 100 isolated teeth, and scattering of postcranial remains

• Many interpretations for these remains, i.e. used fire, ritual, cannibalism, remains from the meals of giant hyenas

• Cultural remains of more than100,000 artifacts indicate site occupation of several thousand years

• Lack of evidence of the control of fire and suggestive evidence of bone accumulation of carnivores cast doubt on whether the cave was home or hearth

Later Homo erectus from Europe

• Atapuerca region in northern Spain, 1.2 mya

• partial jaw with few teeth;closely resembles Dmanisi

fossils; simple flake tools and animal bones

• Gran Dolina, dated to appx 850,000-780,000 ya

• Assigning the fossils to a particular species is problematic,

based on the fragmentary nature of the remains

• Spanish paleoanthropologists place these hominins into a

species called Homo antecessor

Homo erectus Timeline

Technological Trends in Homo erectus

• Expansion of the brain enabled H. erectus to develop

sophisticated tools that span two stone tool

industries: Oldowan and Acheulian

• Biface - stone worked on both sides and used to

cut, scrape, pound, and dig.

• Raw materials transported more consistently and for

longer distances

• Suggests foresight: knew they needed a stone tool in

the future and carried what they regarded as useful

Acheulian Industry • Pertaining to a stone tool industry from the Lower and Middle

Pleistocene.

• Characterized by a large proportion of bifacial tools (flaked on

both sides).

• Multifunctional tools, including uses for butchery

• Most common tool was the hand axe

Did Meat Make Us Smarter?

• Our brains use 25% of out bodies energy

• Meat provides the highest caloric value per unit of any food

type

• It is possible but very difficult for modern humans to meet

their caloric needs eating just raw fruits and vegetables

• This is also linked to the controversial idea that Homo

erectus may have cooked their food.