Later Human Evolution Homo erectus

Homo erectus: Traits Homo erectus lived from approximately 2 million to around 400,000 years ago. Homo erectus is a large brained species, with adult brains ranging from 900 to 1200 cc. This size range means that the larger brained individuals of this species exhibit a fifty-percent increase in brain size over the older Homo habilis. The largest brain sizes of H. erectus fall within the range of modern humans, although the H. erectus brain is configured somewhat differently than our own.

Traits Were from the neck down almost exactly like moderns Had no chin, thick and big brow ridges Bigger teeth than moderns Males were much bigger than females, but this changes over time More robust body Body Size male:170cm,66kg female:150cm, 56kg

Height comparisons

Acheulian Hand Axes Homo erectus was an accomplished tool maker and tool user; hand-axes were widely used in addition to sharp-edged flakes. The tools of Homo erectus are the first in the fossil record to show conscious design of any complexity. Wooden tools and weapons are also assumed to be present in the tool kit of this species, but none has been preserved in the fossil record.

Acheulian Hand Axe

Controlled Use of Fire H. erectus may have been the first species to use and control fire. This milestone in human development occurred 1 to l.5 million years ago. Control of fire may have enabled humans to move out of Africa and into colder climates in Europe and Asia.

Use of Fire Homo erectus invented fire To cook food, scare away animals and travel to colder places controlled fire

Migrate Out-of-Africa The earliest specimens of Homo erectus are found in Africa, but, sometime after 1 million years ago, Homo erectus apparently migrated out of Arica. Tools and remains of this species have been found widely distributed in Europe and Asia. Homo erectus is thus the first human species to migrate out of Africa and adapt to a variety of Old World environments.

Sites in & out of Africa

Migration The earliest Homo erectus finds are in the Rift Valley of Africa and in South Africa. Stone tools and camp sites are widely distributed over Africa, including sites in what is now the Sahara desert. By at least 1 million years ago, H. erectus migrated out of Africa to Asia and Europe. Recent dating techniques applied to earlier finds in Java and the Caucasus mountains indicate dates much earlier than that and would place Homo erectus in Asia over 2 million years ago. Such early dates would, if proven accurate, dramatically overturn the currently accepted chronology of early human development. At this date, however, the earliest claimed dates for H. erectus outside of Africa are still highly controversial.

Habitat/Map Asia (cold) Europe (cold) Africa (hot) Australia (hot) Homo Erectus Asia (cold) Europe (cold) Africa (hot) Australia (hot) Htttp://www.handprint.com/LS/ANC/disp.html

Important Finds Turkana Boy Peking Man Homo Erectus Discovered by Kamoya Kimeu Peking Man Was found near Beijing Name used for the bones of an extinct hominid Reconstruction of Peking man Skull Peking man pic http://www.inhandmuseum.com/LA/erectus/ergaster.html

Variation Individual specimens of Homo erectus vary widely but some trends are visible over time. These artist's reconstructions of three faces from skulls show variations over a period of about a million years. The oldest, approximately 1.5 million years in age, is on the left, and the most recent, approximately .5 million years old, on the right. Seen together, these specimens show the developmental trends within the species. Over time, the face evolved toward a flatter, more vertical plane with a larger and more rounded cranium as brain size increased.

Homo ergaster By 1.9 million years ago, another lineage of the genus Homo emerged in Africa. This species was Homo ergaster. Traditionally, scientists have referred to this species as Homo erectus and linked this species name with a proliferation of populations across Africa, Europe, and Asia. Yet, since the first discoveries of Homo erectus, it had been noted that there were differences between the early populations of "Homo erectus" in Africa, and the later populations of Europe, Africa and Asia. Many researchers now separate the two into distinct species Homo ergaster for early African "Homo erectus", and Homo erectus for later populations mainly in Asia. Since modern humans share the same differences as H. ergaster with the Asian H. erectus, scientist consider H. ergaster as the probable ancestor of later Homo populations.

Homo ergaster: WT 15,000 Narikatome Boy Boy, 12 years Long legs narrow hips and shoulders Vertebrate opening sin spinal cord smaller than moderns Brain size large (850-1100) Front tooth size increase, back tooth decrease Tall (5-5.5 feet), thick bones. 1.6 mya-200 kya

Narikatome Boy The nearly full skeleton at the right belonged to a teen-age boy, 12 or 13, who lived 1.65 years ago near what is now Lake Turkana in east Africa. He was five feet, four inches tall, and his body is remarkably modern looking. This is the most complete find of an ancient human ancestor yet discovered, and it has provided a wealth of information. Yet this immature male had already surpassed a height of five feet at the time of his death, and probably would have attained a height of 6 feet and a weight of roughly 150 lbs.

Homo ergaster in Africa ER 3733 represents a mature female of the early human species Homo ergaster. The gender identification comes from a comparison of the anatomical features of her face with another Koobi Fora for a cranium KNM ER 3883, and the KNM WT 15000 male, found on the opposite side of Lake Turkana. The features of KNM ER 3733 are markedly less robust. It's known to be an adult on the basis of the cranial sutures (which were fully closed), the extent of the wear on the teeth, and the eruption of the third molars before the individual's death.

Homo ergaster (ER3733)

H. ergaster has a more globe-shaped braincase that lacks this torus. Note the difference in the shape of the cranium. On the top, H. erectus has a long cranium with a "transverse torus," a protruding area of bone at the back of the braincase. H. ergaster has a more globe-shaped braincase that lacks this torus. Although the African cranium and the East Asian reconstruction both depict females, the later H. erectus (right) exhibits larger browridges. H. erectus H. ergaster