Prehistoric World

1.77 million

Homo georgicus / Dmanisi Man

Once in the Caucasus, Homo erectus may have discovered that it was not the only hominid living in the region. There is also evidence to suggest that a group of hominids of a much smaller stature were established there.

A collection of 1991 finds from Dmanisi (sometimes shown as Dimanisi) in Georgia in the same layer of sediment as Homo erectus finds has brought to light these little 'people' - who stood at around 1.22 metres tall - but this has caused a lively debate amongst palaeoanthropologists.

So far it has been tricky to work out exactly what species they are. Common thought is that Homo erectus was the first to venture out of Africa and spread around Asia.

But the Dmanisi hominids were not typical of the tall-standing, big brained erectus - instead they were short, long-armed, small-brained, and thin browed, with a far smaller brain cavity - half the size of a modern human - and the huge canine teeth and thin brow of an ape.

However, the tools found alongside fossils were basic choppers and cutters, just like those found at the sites of early, primitive humans in Africa. There were no signs at the archaeological sites of fire having been used (not unusual though, as fire seems first to have been 'tamed' by H ergaster around 1.0 million years ago.

This has led some to believe they may have been Homo habilis. But the relatively ape-like habilis was not thought to have lived outside Africa. Other researchers have coined the term Homo georgicus to describe the finds, and this seems to be sticking, for now.

1.76 million

Homo ergaster
Part 2 of 3

In 2011, the world's earliest sophisticated stone tools were found near Lake Turkana in north-west Kenya.

The teardrop-shaped hand-axes date to about 1.76 million years ago, and would have been used for a range of tasks from chopping wood to cutting up meat. They would have been so useful that scientists describe them as the 'Swiss army knife' of the Stone Age. The tools were probably made by Homo ergaster.

The type of tools unearthed at the Kokiselei archaeological site are referred to by anthropologists as Acheulian technology. They are larger and heavier than the pebble-choppers (Oldowan technology) which were used by ergaster's predecessor, Homo habilis.

The Acheulian hand-axes, known as 'bifaces', also have distinctive chiselled edges. Manufacturing them would have required forethought in design and the careful selection of particular types of starting rocks from which to fashion the final product.

The study shows that the tools were in use some 350,000 years earlier than all previous Acheulian finds. This dating places them closer to the origins of Homo ergaster, and suggests the Acheulian was the proprietary technology of this specific human species.

This invention by ergaster would seem to have happened shortly after the migration of Homo erectus into Asia, which is backed up by the fact that it took hundreds of thousands of years for the technology to become widespread elsewhere in the world.

1.6 million

Less differences between the sexes in Homo ergaster than in previous hominids may reflect a distinctively human pattern of sharing and cooperation between males and females. Homo ergaster probably communicated using gestures combined with a limited range of sounds. Their vertebral canals do not seem to have been developed enough to have given them the control over the breathing needed for complex speech.

H ergaster also seems to have relied more than previous hominids on stone tools for processing food. Although to begin with, ergaster used the aforementioned primitive Oldowan tools, its symmetrical, heart-shaped Acheulian hand axes gave the hominid greater control over the butchering of meat for food.

Again, this seems to be related to changing conditions caused by the occurrence of the first ice age. Hereafter, ice ages occurred at fairly regular intervals of 80,000 to 100,000 years: dramatic falls in temperature and the formation of extensive ice sheets, especially in the northern hemisphere, alternated with warmer periods when temperatures were similar to those of the present day.

One of the best sources of information about Homo ergaster is a skeleton discovered in 1984 by Alan Walker and Kamoya Kimeu at Nariokotome in West Turkana, Kenya. The remains were found to be those of a teenage boy between the ages of eleven and thirteen when he died. Around 1.5 million years ago, the boy's body sank into the marsh where he died and became fossilised.

His teeth show signs of an abscess where his milk teeth fell out, indicating that he may have died from septicaemia (blood poisoning). Nariokotome Boy, as he has been dubbed, was already developing a thick, bony brow ridge above his eyes.

A pair of buck teeth stuck out from a large, projecting mouth below a long, wide nose. He was about 160 centimetres tall and would have stood at 185 centimetres had he reached adulthood. This was clearly a strapping lad, with a body shape which was perfectly adapted to an active life in the sun.

Human populations living on equatorial grasslands today, such as the Masai in Kenya, have the same tall, linear physique. This body shape creates a large surface area over which the body can cool itself more easily, preventing Nariokotome Boy from overheating under the blazing sun.

1.4 million

Paranthropus capensis

A new example of Paranthropus was announced early in 2025. Paranthropus capensis was the exception to the rule - having a diminutive jawbone and teeth instead of the 'nutcracker' jaw which is typical of this species.

Dubbed SK 15, the surviving jawbone behind this identification was originally unearthed in 1949 in a cave at a South African site known as Swartkrans, alongside other Paranthropus fossils and a few early Homo specimens.

Initially, scientists thought SK 15 belonged to a never-before-seen species they called Telanthropus capensis. However, from the 1960s researchers were suggesting that it actually belonged to the relatively slender early human species known as Homo ergaster.

New research on the jawbone in 2024 showed it to be too thick for ergaster though, and with longer and more rectangular molars in comparison to the rounded molars which are found on Homo species.

Instead, based on the jaw shape and the sizes and shapes of the crowns and roots of the teeth, it was decided that SK 15 more likely belonged to Paranthropus, even if it did not match up to any known Paranthropus find.

The findings suggest at least two Paranthropus species co-existed in southern Africa about 1.4 million years ago - robustus and capensis. They probably inhabited different ecological niches, and capensis may have enjoyed a more varied diet than robustus, with potentially different food resources.

1.2 million

Paranthropus boisei
Part 2 of 2

Paranthropus boisei eventually paid the price for being a specialist in a changing world. The onset of successive ice ages spelt the end.

The largest boisei skull specimen found is dated to 1.4 million years old, discovered at Konso in Ethiopia. Some individuals have been found in stratigraphic layers with tools, and also with Homo specimens who often made tools, so there's no clear answer to the question of whether boisei itself used stone tools.

Despite its successful way of exploiting the savannah - from its taste for termites to the wide range of vegetation it had specialised in eating - boisei became a footnote in human prehistory. The species was driven to extinction, probably by an intense period of cooling and drying caused by an ice age.

P boisei was unable to adapt to this new, rapidly changing environment. When Earth's climate became intensely irregular, with fluctuating hot and cold spells, there may have been changes in the proportions of food resources available to boisei. Certain plants could have dwindled or died out. A species' ability to adapt to changing resources, like food, is critical to their survival.

Was the highly specialised boisei unable to adapt if some of their favoured plant foods disappeared due to climatic changes? This is the most likely hypothesis at present.

Like other members of the Paranthropus genus, boisei is characterised by a specialised skull with adaptations for heavy chewing - the strong sagittal crest on the midline of the top of the skull anchored the temporalis muscles (large chewing muscles)

1.2 million

Homo antecessor

The name of this species is highly debated amongst the experts, with many considering the remains to be those of Homo heidelbergensis. The latter has theorised origins which have been pushed back this far from a more widely-accepted date of about 600,000 years ago.

Whatever species they come from, H antecessor fossils are considered to be a successor to Homo ergaster, spreading out of Africa to become the oldest human remains to be found in western and Central Europe.

If H Heidelbergensis is to be reclassified as a European-only ancestor of H neanderthalis, then H antecessor's successor in Africa may well be Homo rhodesiensis.

Remains of over eighty fossils representing at least six individuals and including skeletal and cranial remains were found at Gran Dolina in Atapuerca in Spain, between 1994-1996. These remains date to at least 780,000 years old.

Due to the unique combination of features, the discovers believed that they had found a new species. The name Homo antecessor was announced in 1997.

In 2007-2008, researchers working at Sima del Elefante, also in Atapuerca, recovered remains dating to about 1.2 million years ago. Other remains included stone flakes and butchered animal bones.

The species name 'antecessor' is Latin for 'explorer, pioneer, early settler'. It was assigned due to the belief that these people belonged to the first human population to have entered the European continent. Instead they would appear to be a separate branch, closely related to the common ancestor to Homo sapiens and Homo neanderthalis.

1.0 million

Homo erectus
Part 2 of 4

Homo erectus was still dominant in South Asia, living in small, semi-isolated groups. One such erectus group (according to available but still-controversial evidence) seems to have managed to make its way by sea - despite sea travel previously being thought beyond erectus' capabilities - to the island of Flores in Indonesia (one of a chain of islands stretching east from Java), where by 800,000 years ago it was making stone tools.

The limited resources on the island seem to have forced this group to evolve into Homo floresiensis.

H erectus was already known to have made its way to Java, perhaps as early as 1.5 million years ago. This is where the earliest-known erectus fossils were discovered in the early 1890s (and were initially called Java Man).

Flores was never connected by land bridges either to Asia or Australia. Even at times of low sea level, island-hopping to Flores from mainland Asia involved sea crossings of up to twenty-four kilometres.

The only land mammals here were stegodonts (extinct elephant ancestors) and rodents, the former by swimming and the latter by hitching a ride on flotsam. Since erectus is unlikely to have had the brainpower to fashion a boat, the most likely answer is that it saw something else swimming towards the island and copied it, but possibly with the help of floating debris.

Other erectus groups were beginning to move into Europe, although their presence there would never be very great.

The initial Homo floresiensis population on the island of Flores would have been full-sized Homo erectus specimens, but the limited resources available on the island meant that succeeding generations were born which were shorter and smaller, producing Hobbit-sized humans within 300,000 years

1.0 million

Homo ergaster
Part 3 of 3

Fossil finds in Kenya dated to 930,000 years ago suggest that Homo ergaster was still dominant in Africa. It seems to have become the first hominid to use fire, which enabled it to eat food more easily and also allowed the size of its jaws and teeth to reduce. This resulted in some variation in skull sizes occurring, marking out demonstrable differences at this time between ergaster and Homo erectus.

Fire may have been used as long as 1.5 million years ago for cooking and warmth but whether this was a controlled use of fire is not certain. Charcoal, burnt earth, and charred bones found associated with ergaster fossils may have resulted from naturally occurring fires rather than from intentionally lit and controlled fires.

Recent reports (Current Anthropology Vol 52, 4 August 2011) of discoveries in Wonderwerk Cave, South Africa, suggest controlled use of fire may have been occurring by 1.7 million years ago.

Stratified deposits contain burnt stones, charred-calcined bones and traces of ash which indicate repeated burning events. The discoverers concluded that the fire-makers, most likely ergaster, regularly gathered around the fire to prepare and cook food and also for social reasons.

It is possible that the changes in ergaster were partly the result of the new ice age, which was already bringing climate changes with it. Whatever the cause, the appearance of Homo heidelbergensis was imminent.

900,000

A 2023 genomics analysis included more than three thousand living people. The findings suggested that the total population of direct-line human ancestors plummeted to about 1,280 breeding individuals for a span of about 117,000 years.

The cause was suspected to be an extreme climate event but, whatever it was, it seemingly led to a bottleneck which came close to wiping out ancestral humans.

Such existential pressures which would have been caused by the bottleneck could have triggered the emergence of a new species, either Homo heidelbergensis or Homo bodoensis, or both.

New species can often appear in small, isolated populations, and during times of climatic stress. The period also seems to coincide closely with the disappearance of Homo antecessor.

The decline appears to coincide with significant changes in global climate which turned glaciations into long-term events, caused a decrease in sea surface temperatures, and could have been responsible for a potential long period of drought in Africa and Eurasia.

The time window also coincides with a relatively empty period in the fossil record. Between about 900,000 and 600,000 years ago the fossil record in Africa is very scarce, if not almost absent, while both before and after there are a greater number of finds. The same can be said for Eurasia, with Homo antecessor in Europe until around 800,000 years ago and then nothing for about 200,000 years.

Later populations of humans which took part in the 'Out of Africa II' migration (see 'related links' in the sidebar) had only weaker evidence of this particular bottleneck because they experienced their own far more recent bottleneck around 80,000-70,000 years ago (see 'Bottleneck 2').