Homo sapiens is not this planet’s first experiment in big brains. Prior to our arrival on the scene 200,000 years ago, a number of other Homo species preceded us and, for the most part, survived many times longer than we have before becoming extinct. It remains to be seen how long we will survive. Although there is still considerable lack of consensus regarding their lines of ancestry and progeny, they have been identified from their fossil remains as:
Homo habilis (2.6 – 1.4 million years ago)
Homo ergaster (2.5 – 1.7 million years ago)
Homo erectus (1.9 million – 100,000 years ago)
Homo antecessor (1.2 million – 800,000 years ago)
Homo heidelbergensis (600,000 – 230,000 years ago)
Homo neanderthalensis (230,000 – 24,000 years ago)
In this post I want to look briefly at three of them.
Homo habilis (2.6 – 1.4 million years ago)
About 2.6 million years ago, at Turkana in northwest Kenya, a species of Australopithecus (probably A. africanus) evolved into the first species of the Homo genus. A hunter and meat-eater, Homo habilis or “handy man” is so named because of his use of flaked stone tools for killing and dissecting other animals. It was the beginning of the Stone Age. The remnants of tools found at a mass production site at Lokalalei, west of Lake Turkana, and dated to 2.35 million years ago, suggest that the tool makers there had enough smarts to plan their raw material procurement and manage the production process.
The male of the species stood about 5’0” tall and weighed about 100 pounds. His face was still primitive, but his brain size (660-700 cc) was 50% larger than his australopithecine forbears. His brain shape is also more humanlike, suggesting that he may have been capable of rudimentary speech. Despite the many theories that have been proposed, we still have no idea why hominid brains suddenly began to grow. Anthropologist Ian Tattersall says: “There is simply no compelling reason we know of to explain why human brains got large.”
Their life would have centred on survival, with energy devoted primarily to meeting their physical needs. They never learned to harness fire. Their sense of time probably did not extend much beyond tomorrow. Nor is there any hint of the death denial that later emerged in Neanderthals in association with burial rituals. For habilis, no food is death, and a full stomach is as much immortality as they hoped for.
Homo erectus (1.9 million – 100,000 years ago)
Homo erectus and Homo habilis probably shared a common ancestor and co-existed in Africa for about 500,000 years. But unlike habilis, erectus quickly migrated out of Africa. His fossilized remains, dated to 1.8 million years ago, have been found from the Atlantic coast of Europe to the Pacific coast of China.
The nearly complete skeleton of a 9 – 12 year old boy (“Turkana boy”), who died 1.54 million years ago, gives us the best picture of H erectus. Though still sporting protruding jaws and thick brow ridges, he looks more human than his predecessors – long-limbed and lean, very strong, and intelligent enough to spread successfully over a vast area. Brain size averaged 1000 cc – 50% larger again than that of habilis – and may have included a Broca’s area in the frontal lobe associated with speech.
Almost wherever erectus went, he left behind his signature tool – a teardrop-shaped, flint hand-axe. A recent excavation at Olorgesailie in Kenya’s Great Rift Valley has revealed a 10-acre site where these so-called Acheulean tools were mass produced in incalculable numbers from 1.2 million to 200,000 years ago. For a million years it operated as a well organised “factory” for fashioning new axes and re-sharpening blunt ones. Strangely, no human bones have ever been found there. It seems that H erectus went somewhere else to die.
They lived in small self-sustaining bands of 15-30 people in semi-permanent cave shelters, began using animal skins for clothing, and were the first to harness fire – perhaps as early as 1.6 million years ago and certainly since 800,000 years ago. Since there is no evidence that they cooked food, a fire in the hearth may have contributed both to physical warmth and to a sense of unity and intimacy within the group. The bones of a 1.7 million year old woman reveal that she had lived for months with an agonizing condition before dying, indicating that someone had looked after her – perhaps the first evidence of tenderness in human evolution. And the oldest known remains of a purpose-built hut, found north of Tokyo and dated to 500,000 years ago, testifies to their evolving technology and cognitive ability.
When Homo sapiens emerged in Africa 200,000 years ago, with a brain yet another 50% larger than that of erectus, they simply out-competed their smaller-brained predecessors. And by the time sapiens arrived in China c. 50,000 years ago, there was no longer any evidence there of H erectus. In fact, there are no erectus remains in China after 100,000 years ago. It seems likely that a deep freeze either drove them away or killed them off before sapiens arrived. Whatever happened, this now-extinct predecessor deserves our respect, for they walked the Earth for close to two million years.
Homo neanderthalensis (230,000 – 24,000 years ago)
In 1856, three years before Darwin published On the Origin of Species, a skull was discovered in the Neander Valley of western Germany. It belonged to the first hominid ancestor to be discovered – Neanderthal Man. Recent evidence indicates that they shared a common ancestor with modern humans – probably Homo erectus. They dominated Europe, the Middle East, and parts of western and central Asia for some 200,000 years until H sapiens arrived and displaced them. Indeed, current genetic evidence suggests that interbreeding took place with H sapiens 80,000 – 50,000 years ago, resulting in 1 – 4% of the genome of Eurasian people having been contributed by Neanderthals.
Males stood about 5’6” in height; females were about 6” shorter. Like erectus, they had a protruding jaw and receding forehead. Their brain size of 1450 cc was equivalent to that of modern humans. What distinguished them anatomically were their heavy bones and powerful muscles. They would have been extraordinarily strong by modern standards. Almost exclusively carnivores, they hunted large animals such as mammoths and endured brutally hard lives. As a species they were magnificently resilient and practically indestructible.
Neanderthal culture is identified with its cave dwellings, extensive use of fire, personal ornaments, well-wrought stone implements, and skin-covered huts more advanced than those of any preceding peoples. Painted scallops and cockleshells found recently in Spain suggest that they had a capacity for symbolism, imagination, and creativity similar to H sapiens.
The Neanderthals lived in a dramatic universe filled with spirit powers that required symbolic rituals and sacrifice – the earliest signs of a religious mode of consciousness. Almost inaccessible sanctuaries in high mountain caves show cave-bear skulls ceremonially disposed in symbolic settings. The bear is a venerated beast whose powers survive death and are effective in the preserved skull. The burial of their own dead also suggests a life to come. A 10-month-old Neanderthal baby, whose remains were discovered in a cave in northern Israel, was deliberately laid to rest in a small niche in the cave. The jawbone of a red deer that had been offered as a sacrifice was lying on the infant’s pelvis – clearly an attempt to cope with the imprint of death on the Neanderthal psyche.
Neanderthals were competitively replaced by Homo sapiens within the past 50,000 years. They disappeared from Asia 50,000 years ago, from Europe 30,000 years ago, and finally from Gibraltar 24,000 years ago. It was probably natural selection that did them in. Modern humans were much more efficient hunters and would have gradually excluded them from their food resources. What Neanderthals could only do with brute force, modern humans accomplished with tools and brains.
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