Early Skulls |
Until recently, the earliest
evidence archaeologists had for human occupation in Ireland was dated to around
8000 BC. However, scientists have recently dated a fragment of butchered bear
bone from a cave in County Clare to 10,500 BC, thereby, pushing back the date
for human settlement in Ireland by 2,500 years. At a time of mass migration in
the world it is, perhaps, timely to consider our origin as a species and how
humans went on to inhabit the globe.
Humans and chimpanzees are very
closely related and separated about 7.4 million years ago. There is only a 1% difference between the
chimpanzee genome and our own suggesting that we have a common ancestor.
Today, modern humans or Homo
sapiens, inhabit the whole earth. Looking back over the last half a million
years, the picture was much more diverse, with three distinct lineages
appearing: Homo erectus in Asia; and Homo heidelbergensis giving rise to Homo
neanderthalensis in Europe and Homo sapiens in Africa.
Image of Neanderthal Man |
The Neanderthals thrived in
Europe for around 300,000 years before modern humans arrived. The reason for
the demise of this successful species remains a mystery. Neanderthals occupied
Europe for at least 100,000 years during a period when glacial cycles dominated
the climate. Excavations in Ibex, Vanguard, and Gorham’s Caves in Gibraltar
have revealed evidence of Neanderthal occupation dating to possibly as late as
28,000 years ago. This makes Gibraltar the most recent Neanderthal occupation
site yet discovered.
By 200,000 years ago, many
innovations had been made in stone tool technology. For example, large handaxes
became less common and were replaced with a range of smaller tools in more
diverse toolkits. Tools made of flakes were favoured over large cores. Humans
use tools to a much higher degree than any other animal and are the only
existing species known to build fires, cook their food, wear clothes, and
create art.
The first fossil evidence for any
modern humans outside Africa comes from the Middle East, from the archaeological sites of Skhul and Qafzeh
in Israel, dating to around 120,000 years ago. However, this early expansion of
modern humans was not maintained. A change to a colder climate may have driven
those pioneers back into Africa. The expansion of our own species out of Africa
that eventually led to the colonisation of the globe would start later – after
100,000 years ago.
Map showing the spread of humans |
This dispersal out of Africa is
believed to have started from Northeast Africa. Modern humans later spread
worldwide, replacing earlier ancestors either through competition or
interbreeding. They inhabited Eurasia (Europe and Asia) and Oceania (a region
centred on the islands of the tropical Pacific Ocean) 40,000 years ago, and the
Americas at least 14,500 years ago.)
Around 50,000 years ago, an
improvement in the global climate, leading to the appearance of habitable lands
where once there was desert, may have provided the opportunity for modern
humans to spread into Europe. Evidence
from early modern human sites in Europe suggest that these early people moved
into the continent along coasts and rivers, as they had done elsewhere.
Until about 10,000 years ago,
humans lived as hunter-gatherers living in small nomadic groups, often in
caves. Agriculture began independently in many parts of the world with
different domesticated species. Hunter-gatherers already knew a great deal
about plants and animals and often manipulated them or the environment to
increase productivity. Farming entered Europe around 7000 BCE and was the main
way of life across Europe by 4000 BCE.
Farming communities spreading
into Central Europe around 5600 BCE had to adapt to bitter winters, heavy
rainfall, and dense forests. They kept mainly cattle and farmed open river
terraces. Farming spread through Western Europe and into other parts of
Central, Northern, and Eastern Europe by 4000 BC. Animals were initially kept for meat, hides,
bones, and manure. Feeding animals on crop surpluses made them a food reserve,
and large herds signified wealth and prestige. Domestic animals became far more
important when people began using them also in other ways: for milk, wool,
eggs, traction, and transport.
Examples of early metal working |
The social importance of metals
for making prestige objects with which people could show their status, led to
the early development of metallurgy. Only later, with the development of
alloys, did metal also become significant as a material for tools and weapons.
Smelting copper and lead ores began in West Asia after 7000 BC, and by the
sixth millennium BC casting was possible. By 2500 BC, metallurgy had spread
through Europe. Bronze-working became widespread after 1800 BC with trade
routes linking much of the continent circulating metals, particularly tin.
Prehistoric religion reflected
people’s need to understand the world and explain disasters. Through rituals
and offerings ancient societies sought to bribe or appease the divine forces
controlling the world or its individual components. Since Neanderthal times,
people have practised rites that showed concern for their dead, perhaps linked
to a belief in an afterlife.
Newgrange Stone Age Passage Tomb |
Burial in graves or tombs or
under house floors, was common. Many societies practised other rites, including
cremation, exposure, or disposal in watery places. Some thought it important to
preserve the body and undertook mummification (for example, in Egypt and South
America). Monumental tombs, such as tumuli, pyramids, and megaliths, could link
the living and the dead to ancestral lands or sacred places.
Humans and chimpanzees are very
closely related and separated as recently as about 7.4 million years ago. Our
ancient cousins, the Neanderthals thrived in Europe for around 300,000 years
before modern humans arrived and may have survived until around 28,000 years
ago. Innovation in stone tool technology aided the development and eventual
spread of modern humans throughout the globe. Later developments in metal
working and agriculture assisted this dispersal. Since Neanderthal times,
people have practised rites that showed concern for their dead, perhaps linked
to a belief in an afterlife.
Migration is not something new
and, in a sense, we are all migrants whose ancestors were black and lived in
Africa a long long time ago.
Further reading: Evolution - The Human Story (2011) by Dr.Alice Roberts
See also BBC DVD The Incredible Human Journey