Homo erectus

***Homo erectus*** (Latin: "upright man") is an extinct species of the genus _Homo_. Fossil remains were found in Java (1890s) and in China (1921). Nearly all of them were lost during World War II, but there are casts that are considered to be reliable evidence.

Early in the 20th century it was believed that the first modern humans lived in Asia. But during the 1950s and 1970s, many fossil finds from East Africa (Kenya) showed that the oldest hominins came from there.

### Skull and brain

_H. erectus_ had a cranial capacity (brain size) greater than the earlier _Homo habilis_. The earliest _H. erectus_ remains have a cranial capacity of 850 cm³, while the latest Javan specimens measure up to 1100 cm³. This overlaps that of _H. sapiens._

The frontal bone is less sloped and the dental arcade smaller than in australopithecines. The face is more vertical (less protrusive) than either the australopithecines or _H. habilis_, with large eyebrow-ridges and less prominent cheekbones. The face is longer than most australopithecines, with a larger brow and smaller cheekbones.

### Hair & sweating

Body hair protects the skin from wounds, bites, heat, cold, and UV radiation. Also, it is used as a communication tool and as a camouflage.

The first member of the genus _Homo_ to be hairless was _Homo erectus_, originating about 1.6 million years ago. The most widely accepted explanation is that H. Erectus evolved hairless bodies and increased sweat glands to make it easier for their bodies to cool down. Man's ancestors moved from living in shady forest to open savanna, and they needed to be able to keep cool.

This change in environment resulted in a change in diet, from largely vegetarian to hunting. Hunting game on the savanna also increased the need for the body to stay cool.

Anthropologist and paleo-biologist Nina Jablonski thinks the ability to lose body heat through sweating helped make possible the dramatic enlargement of the brain. The brain is the most temperature-sensitive human organ. The ability to stay cool allowed the brain to enlarge over time.

The loss of fur was also a factor in other adaptations. Some of these changes are thought to be the result of sexual selection. By selecting more hairless mates, humans accelerated changes which were first done by natural selection.

Sexual selection may also account for the remaining human hair in the pubic area and armpits, which are sites for pheromones, while hair on the head continued to provide protection from the Sun.

Humans had hairless bodies, upright posture, and high brain capacity by 260,000 to 350,000 years ago.

### Height and sexual dimorphism

These early hominins stood about . Only 17 percent of modern male humans are taller. They were slender, with long arms and legs.

The sexual dimorphism between males and females was slightly greater than modern man, with males being about 25% larger than females. The discovery of the skeleton KNM-WT 15000, "Turkana boy" (_Homo ergaster_), made near Lake Turkana, Kenya by Richard Leakey and Kamoya Kimeu in 1984, is one of the most complete hominid skeletons discovered. It has provided important information about how humans evolved.

## Tools

The most distinctive tool of _H. erectus_ was the Acheulean hand axe, first invented 1.8 million years ago (mya). This hand axe was made by chipping a suitable stone with a hammer stone. Later, the Neanderthals used a soft hammer made of deer antler bone to make better tools.

The Acheulean hand axe lasted for over a million years as the main tool. Its main use was for butchering meat. This we know because different uses leave different micro-wear on the hand axe surfaces.

## Descendants and subspecies

_Homo erectus_ remains one of the most successful and long-lived species of the _Homo_ genus.  It is generally considered to have given rise to a number of descendant species and subspecies. The oldest known specimen of the ancient human was found in southern Africa.

- ***Homo erectus:***
_Homo ergaster_,
_Homo erectus pekinensis_,

- **Other related species:**
_Homo antecessor_,
_Homo cepranensis_,
_Homo floresiensis_,
_Homo georgicus_
_Homo heidelbergensis_,
_Homo neanderthalensis_,
_Homo rhodesiensis_,
_Homo sapiens_,

## Individual fossils

Some of the major _Homo erectus_ fossils:
- Indonesia (island of Java): Trinil 2 (holotype), Sangiran collection, Sambungmachan collection, Ngandong collection
- China: Lantian (Gongwangling and Chenjiawo), Yunxian, Zhoukoudian, Nanjing, Hexian
- India: Narmada (taxonomic status debated!)
- Kenya: WT 15000 (Nariokotome), ER 3883, ER 3733
- Tanzania: OH 9
- Vietnam: Northern, Tham Khuyen, Hoa Binh
- Republic of Georgia: Dmanisi collection
- Turkey: Kocabas fossil

### Recent research

Fossil _H. erectus_ skulls found in Java in the 1930s have recently been redated. There are 12 skullcaps (the top part of the skull) and two lower leg bones. The recent research shows that on Java, _H. erectus_ survived to about 100,000 years ago. The research gives a definitive age of between 117,000 and 108,000 years ago. That is much a much longer survival than in any other part of the world, so far as is known.

This means, says the report, that _H. erectus_ was still around when our own species was [elsewhere] walking the Earth. Java is an island, and presumably it had not yet been discovered by Neanderthals or our own species. Remains suggest that our own species did not reach Java until about 39,000 years ago.

## Related pages

- Australopithecus
- Human timeline
- Life timeline

## Other websites

- MNSU
- Archaeology Info
- Smithsonian
- Homo erectus at Stanford University
- Possible co-existence with Homo Habilis - BBC News
- John Hawk's discussion of the Kocabas fossil