Prehistoric World

150,000

Homo sapiens
Part 1 of 6

Fully modern Homo sapiens ('wise man') may not have appeared in its current form until as late as 80-60,000 years ago.

Prior to this, the first appearance of archaic man around 200,000 years ago had followed about 100,000 years of gradual transition from the features of its possible predecessor, Homo Heidelbergensis (possibly now replaced by Homo bodoensis), to those of Homo sapiens. Perhaps this is the best example of evolution at work - not a sudden process (although in evolutionary terms 100,000 years is extremely brief) but a gradual transition across several hundred generations.

A small development in the jaw here, a minor cranial enlargement there, a little less body hair than with the father... Even today, such changes would not seem especially remarkable on a case-by-case basis. It would be hard to see evolution happening at all.

Homo sapiens became established in Africa after transitioning from - it has generally been assumed - heidelbergensis and testing out various advancements in the form of Homo rhodesiensis and Homo sapiens idaltu (and quite possibly others which remain to be discovered).

Homo sapiens had a characteristic look: their faces were (and of course still are) small and tucked under a high, domed braincase. They had small eyebrow ridges and their lower jaw ended in a prominent chin. On average, their bodies were less robust and less muscular than those of earlier hominids.

The appearance of modern humans coincided with the appearance of highly crafted tools, efficient food-gathering strategies and a complex social organisation, although precisely when this occurred is still very much open to debate.

New dating in 2017 of fossils found in Israel indicated that some Homo sapiens groups had managed to make the crossing out of Africa during one of the periodic phases which allowed such access. They were present there by about 185,000 years ago (with a possible window of 10,000 years in either direction). The fragments of jaw discovered there showed very clear modern human characteristics.

This was not a major 'Out of Africa' migration, though. Just one in a series of temporary expansions by small groups into the Levant before climate or Neanderthal competition either forced them back into Africa or killed off these migrant bands.

146,000

Homo denisovan (Homo longi / Homo daliensis)
Part 3 of 4

The rediscovery in China in 2018 of a huge fossilised skull which had been hidden in 1933 sparked some discussion about its origins. Chinese researchers were quick to give it a new species name: Homo longi or 'Dragon man'.

The skull is 23cm long and more than 15cm wide. It is substantially larger than a modern human skull and has ample room, at 1,420ml, for a modern human brain. Beneath the thick brow ridge, the face has large square eye sockets, but is delicate despite its size.

In general it is closer to modern humans than it is to Neanderthals, but may be similar to a 1978 discovery in China's Dali county, earning it the alternative name of Homo Daliensis.

It clearly forms a separate lineage from either humans or Neanderthals though, with the possibility (especially given the relative vicinity of the Altai Mountains) that it forms a branch of Denisovan.

That potential link was strengthened by fresh research which was published in 2024. Denisovans appear to have supplied an interbreeding gene to modern Tibetans which makes it easier for them to survive in their high-plateau climate.

100,000

Homo sapiens (Nesher Ramla)
Part 2 of 6

In search of new food supplies, Homo sapiens began to cross from Africa into the Near East. They may not have been the first of their kind to make the journey, however, as the Nesher Ramla Homo group already seem to have been well established by about this time (see the Mousterian culture link, right for more).

By this Late Pleistocene period, its numbers appear to have been dramatically reduced by a lack of food stocks, perhaps to as low as two thousand individuals in the main groups (according to genetic research in the early 2010s), which meant that for a while Homo sapiens was perilously close to extinction. Other, smaller groups seem to have remained in Africa.

By a strange twist of fate, the harsh conditions which caused this near extinction may also have allowed the cultural explosion which gave rise to human behaviour as we know it today. By 2004 Professor David Goldstein, a molecular biologist at UCL in London, had announced evidence uncovered to back up the idea of a very ancient population bottleneck.

A bottleneck is an event which reduces the genetic difference, or diversity, in a population of animals. One way this can occur is through a catastrophe which wipes out a large proportion of a population.

When the genes of modern people from all over the world are compared, they are remarkably similar, suggesting that the ancestors of all living people expanded from a small population which survived a bottleneck. The genetic data suggested that the bottleneck was not a recent occurrence, putting the likely date for this event at just before 100,000 years ago.

This was at the very dawn of man's migration out of Africa, although some opinion places that event later, so Africa was certainly the location of the bottleneck event.

It's not known what caused this bottleneck. But a plausible candidate is emerging. By measuring the ratios of different oxygen isotopes in ice cores, scientists can reconstruct climatic changes over time. Oxygen isotope data suggests that between 190,000 and 130,000 years ago - a period known as 'oxygen isotope stage 06' - Africa was drained of moisture and became a parched wasteland, with little to sustain populations of modern humans.

The scale of climatic change seen at this time could be responsible for what has been seen in the genetic data.

95,000

Homo floresiensis

A tiny species of human existed in Indonesia at the same time as Homo sapiens was first migrating out of Africa.

Homo floresiensis was a one metre-tall species which lived on the island of Flores (near Java). It had long arms and a skull the size of a large grapefruit, and it shared its habitat with a golden retriever-sized rat, giant tortoises, and huge lizards - including Komodo dragons - and a pony-sized dwarf elephant called stegodon which floresiensis probably hunted.

Floresiensis evolved from Homo erectus, whose remains have been discovered on the Indonesian island of Java and may also have existed to the north of Flores Island, although no finds have so far been discovered.

Homo erectus may have arrived on Flores about one million years ago, evolving its tiny physique in the isolation provided by the island in response to the local scarcity of resources (later influxes of Homo sapiens appear to have evolved in the same way to produce pygmies).

Homo sapiens reached the area by 50,000 years ago, by which time this earlier hominid may already have died out. The finds at Liang Bua were initially dated to a point just before 12,000 years ago, when a volcanic eruption snuffed out much of Flores' unique wildlife, but subsequent analysis has pushed the finds back to between 50,000 and 60,000 years ago.

The initial 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

The initial finds also suggested an arrival date on the island for floresiensis of around 95,000 years ago. But with more information now available this date has also been pushed back, to around 700,000 years ago.

The latest discovery, from Mata Menge in 2015, was of fossils which date to this period. They indicated that the normal-sized erectus individuals who first set foot on Flores shrank 'rapidly' to become Hobbit-sized. The remains are of at least one adult and two children, who are all just as small as their descendents.

Stone tools at the same site are even older, at around one million years. It seems likely that a small erectus population found itself trapped on the island and made the best of the situation. Homo erectus was too primitive to be able to craft boats, so they may either have been carried there accidentally by storm weather or they found a temporary land bridge which has left no trace in today's archaeological record.

Once stuck on the island, they adapted remarkably quickly to the lessened resources. In just 300,000 years they were fully Hobbit-sized, a remarkably quick transformation in evolutionary terms.

A branch which is probably related to floresiensis, Homo luzonensis, has also been found in South-East Asia.

90-70,000

Homo sapiens
Part 3 of 6

Having migrated out of Africa and into the Near East over the course of several thousand years, some groups of Homo sapiens followed the coastline, heading eastwards into Persia and South East Asia.

Other Homo sapiens groups settled along the Fertile Crescent and in the south-eastern corner of Anatolia. They lived alongside tribes of Homo neanderthalis, and there was a considerable overlap in the competition for resources between the two species which lasted for at least 30,000 years (as proven by the discovery of Kebara, a Neanderthal fossil found in Israel and dated to 60,000 years ago).

This span was nearly five times longer than when sapiens later reached Europe. The considerably smaller numbers of sapiens at this time, as they moved into a land dominated by neanderthalis probably goes a long way to explaining this.

However, one significant drawback for Neanderthals was the fact that their physique forced them to maintain a high calorific intake. They were forced to hunt for food containing twice as much energy as that required by Homo sapiens.

Once they found themselves in direct competition with increasing numbers of Homo sapiens, their hunting successes would have been harmed, perhaps significantly. This would certainly have had a detrimental effect on their existence.

Did this process of being out-competed by sapiens cause Neanderthal tribes problems? Not immediately, but over time they would have suffered. By the period between about 60,000 to 50,000 years ago, some of them were interbreeding to a limited extent with local sapiens populations, enough to leave a trace DNA of up to four percent in today's Europeans and Asians.

Principal sites showing the most recent evidence of Neanderthals - notice how the later populations are all congregated in Iberia