Homo erectus was an early hominid species which spread from Africa through Asia, as far as present-day Indonesia, during a time about 1.8-1.3 million years ago. In some locations it then lived until several hundred thousand years ago; fossilized remains in Java and elsewhere in southeast Asia suggest that separate lines of ancestors of Homo erectus may well have survived until the last hundred thousand years, in a line of descent separate from hominid species elsewhere which led to anatomically modern Cro-Magnon humans. Although its precise position within the human genetic family tree is still uncertain, Homo erectus is most significant for one clear fact: it is the first known hominid species to have mastered the use of fire.
- About Homo Erectus -
Homo erectus, whose name mistakenly applies that it was the first to walk upright, i.e. bipedally, originated in Africa at least 1.8 million years ago and then emigrated outwards through Asia. H. erectus had a larger brain than its predecessor, H. habilis, and would have stood at a height similar to modern humans, although their bodies would have been substantially more muscular. Males would have been about one-quarter larger than females, which is more significant than people today but much less significant than the australopithecines, suggesting that more modern reproductive practices were emerging in place of earlier societies organized around singular, overwhelming alpha males.
Like Homo habilis, Homo erectus used stone tools, although its tools were more complex than those of H. habilis (and less complex than those of later H. ergaster societies). By the time the leap from Oldowan to Acheulean stone tool technology occurred in Africa under H. ergaster, archeologists believe, H. erectus had already been displaced to Asia. However, they may have invented rafts or other boats (in order to reach islands where their specimens have been found), and they were almost certainly among the first hunter-gatherers.
- Use of Fire -
Homo erectus and Homo ergaster - the distinction between the two is unclear (and possibly nonexistent, as discussed below) - are also significant for being the first Homo societies to master the controlled use of fire. Originally this would have been limited to capturing, containing, and feeding wildfires started by natural sources, like lightning strikes. It would only have been much, much later that our ancestors learned how to create fire themselves. In the interim, the societies which possessed and came to rely on fire for warmth and cooking, but not could produce it themselves, would almost certainly have placed an immense importance on their fire, perhaps even attributing religious significance to it. For substantial periods of time, mysterious fire could literally have meant life to these people - and extinguishing the fires of their enemies could have meant death, in the same way.
Evidence at sites in Kenya suggests that Homo erectus could have been using fire as late as 1.5 million years ago, although it cannot be ruled out that these are simply the hardened clay left by wildfires which swept over an inhabited location. Evidence from more recently, beginning about 400,000 years ago, is much clearer. At these sites, particularly in present-day Israel and Palestine, Homo erectus clearly used fire to cook food, leaving behind charred bone remains. Similar burnt remains have been found at sites in China and in Java.
Mastery of fire had immense consequences for humans, going well beyond simply a useful source of warmth that allowed Homo societies to survive in climates that previously would have been deadly. It also allowed the use of cooking, which gained us a wide variety of new food sources: meat which previously could not have been safely eaten, as well as various foods whose nutritious content is released through cooking, and others which are made non-toxic through cooking. Recent evidence has suggested that it is difficult, although not entirely impossible, to gain adequate nutritious requirements for a modern human being through eating raw food alone. To this extent, therefore, we have not only come to use fire to improve our lives: we have evolved to a point where we actually need fire in order to survive.
- Fate and Relationship to Early Humans -
Homo erectus's fate is clear - it eventually died out - but the significance of this is less clear. Logically, as a member of the Homo genus, it was clearly an ancestor of the earlier species Homo habilis. However, archaeologists are beginning to suspect that initial beliefs that Homo erectus was next in the human family tree, and that from this species descended the direct ancestors of humans, like Homo heidelbergensis and (ourselves) Homo sapiens, was actually mistaken.
The evidence indicates that, while Homo erectus migrated out of Africa, those who remained shared the land with, and may have been eventually displaced by, a separate species known as Homo ergaster. There are not sufficient specimens to conclude for certain that Homo erectus and Homo ergaster were separate species, rather than simply subspecies which diverged somewhat as a result of the dispersal from Africa into Asia. What is seemingly clear is that, later on, the direct descendants of modern humans emerged from Africa as part of a separate migration. At any rate, the African rather than Asian branch of the Homo genus was responsible for producing modern humans; therefore, if Homo erectus ended up as a separate species in Asia, then it was essentially pushed out of the core lineage of modern humans. The theory that Homo ergaster rather than Homo erectus is our direct descendant is currently gaining strength, but could always be overturned again following the discovery of new specimens.