Evolution refers to the slow process of human adaptation over millions of years. The roots of humanity are believed to lie in South Africa, where the earliest proof of hominids has been discovered. Fossil evidence in East Africa has also cast light on our history as human beings.
Before we look at the Hominid discoveries in South Africa and East Africa we need a basic understanding of the concept of evolution and its theories, as well as archeology.
What is evolution?
Evolution refers to the process of adaptation and physical changes of living organisms over many generations.
Where do humans come from?
Humans belong to the “Homo” genus. There are three different species in this genus called the Homo habilis, Homo erectus and Homo sapiens, or human beings like us. There are many different theories about the origins of humans and much debate around this issue.
There are many different theories about the evolution of the human being and all of these deal with the origins of humans as we are today. The best known theory was presented by Charles Darwin and is called “Darwin's Theory of Evolution”. This theory argues that all life comes from the same ancestral source and that all living things are related. Darwin believed that complex organisms, like humans, evolved or developed from simple creatures over a long period of time through a process called “natural selection”. These simple creatures themselves developed from non-living matter. This process occurred through changes in genetic structure to make living organisms better adapted to its environment. This enabled survival and supports the belief in “survival of the fittest”. Evolution happens very slowly and can take millions of years.
Darwin's theory is by no means the only hypothesis on the origins of humans and their evolution. It is difficult to say which theory is correct because we find out new things about our own development and ancestors every day through archaeological and scientific discoveries. Many Christian institutions disagree with Darwin's theory because in their belief system the first man, Adam, was created by God out of dust, while the first woman, Eve, was created out of Adam's ribs. The evolutionary theory suggesting that humans' ancestors are apes also does not fit with many religious groups who believe humans were made in the image of God. Some scientists also disagree with Darwin.
Read more about archaeology.
You can read more about Darwin and his theory by visiting: www.darwins-theory-of-evolution.comThere are also other evolotionary theories: (try find out more about these theories by doing some internet research)
- The Aquatic Ape Hypothesis
- Mitochondrial Eve
Archaeology What is archaeology and why is it important?
We have many different ways of finding out what happened in the past. History has been recorded in writing, on film and photographs and in oral records of people who were there. All of these methods are only used to record fairly recent history. All of these records can be destroyed by fire or water, and are presented from the point of view of the writer or recorder.
The period before we used this way of recording is called pre-history. We can only study pre-history through archaeology. Archaeology is the study of the past by using the remains left by ancient people. Archaeologists look at bones left after meals, or the skeletons of animals and ancient people, broken pots, ruins, works of art, weapons and any other leftovers of ancient times. This science shows us the everyday life of our ancestors and is valuable because it tells us who our ancestors were and how they existed and evolved. It is a way to rediscover the past!
Where did it begin?
Even the Romans collected ancient relics, but they did it for money or curiosity rather than for information about the past. Archaeology as we know it is rooted in the studies of 17th and 18th century British historians John Aubrey, who lived from 1626 to 1697, and William Stukeley, who lived from 1687 to 1765.
Both of these gentlemen studied ancient sites and tried to determine their age and uses. They collected relics and even made very basic excavations to try to find proof of their theories. Both also had problems with chronology because they didn't have any scientific way to determine the date of their finds.
Stone Age Bronze Age Iron Age
At the time an important religious figure worked out a theory that, according to the Bible, the world was created in 4004 BC. Because they were Christian, the two researchers based their timescale on this. They also thought that artifacts they found were related to status rather than age. Stone tools and weapons belonged to poor people, iron objects to the middle class and bronze to the rich. Today we know that these materials actually relate to the three-age system, the Stone, Bronze and Iron Ages.
The “father of modern archaeology” was General Pitt Rivers who used all the skills he had learned as a soldier and his ordered and curious mind to excavate in an orderly manner in the late 19th century. He tried to answer specific questions with his investigations and he mapped and photographed all of his sites. He also understood that archaeological sites were made up of layers in the ground and that small pieces of artifacts were very important. He kept records of the locations and positions of his finds and published them, as well as exhibiting models of the sites.
Aubrey's greatest find was what we know as Stonehenge in Avebury, England. He realised that the site was older than the Roman era and brought it to the attention of the King, Charles II. The king ordered him to draw up a complete description of the stone circle after which he also wrote a book called “Monumenta Brittanica”, which showed an enormous amount of drawings and notes on sites from many different periods.
William Stukeley's investigations
William Stukeley was the first historian to use excavation as a way to investigate ancient sites he discovered. He drew many conclusions before large-scale agriculture changed the landscape in Britain and his writings are still useful because of this. He found a long enclosure near Stonehenge, which he saw as a Roman chariot racing track from prehistoric times. He named it the “cursus” and it is still called that today.
Archaeology has kept on developing over the past 200 years and today there are new techniques to discover and date artefacts. We can use bone, charcoal, wood and leather to find out when a specific tool was used. This allows us to be more accurate about finds and sites and to learn the truth about the earth's history.
Early Hominid discoveries in South Africa What is a hominid?
Hominids are a biological group or family that includes humans, human-like animals like Gorillas, Chimpanzees and Orangutans, and our ancestors. This group used to only include humans and their ancestors, but this has changed.
Where in southern Africa do we find fossils of hominids? Taung
In 1924 Professor Raymond Dart, an Australian-born academic at the University of the Witwatersrand, was given a fossilised skull that had been discovered while blasting in a limestone quarry in Taung. The skull was still stuck in a piece of limestone and it took 73 days to get rid of all the stone around it and nearly 4 years to get all the parts of the 2,5 million year-old skull out of the rock.
Professor Dart soon realised that this find was very special and he named it Australopithecus africanus in 1925. The skull was very small and he nicknamed it the “Taung Baby” because it had only been about 3 or 4 years old when it died. He also believed that this species fell between humans and apes in evolution.
Why could the Taung Baby be the link between humans and apes?
Professor Dart believed that this skull was a fossil of one of our ancestors because the hole at the bottom of the skull, where the spinal cord comes out, was in a position that meant the child was bipedal, or walked on two legs. Its canine teeth were also short, which made it closer to a human than an ape.
Most paleontologists of the time disagreed with Dart because they felt that the human being's earliest ancestors would have had bodies like apes, but brains like humans. Today we know that Professor Dart was right, but his claims were not really believed until the 1940s.
The oldest fossils of hominids are between 3,3 and 2 million years old and were discovered at the Sterkfontein Valley landscape, which is in both western Gauteng and the North West Province. This place is also called the Cradle of Humankind because it shows the oldest remains of our ancestors found in the world and includes proof of early stone-age, middle stone-age, later stone-age, early and late iron-age and modern people. Thousands of fossils that show human evolution over the past 3.5 million years have been found here since 1936. These fossils are important because they show how our human ancestors lived, what they ate and what animals and plants lived around them.
UNESCO (United Nations Educational, Scientific and Cultural Organisation) declared the area a World Heritage Site in 1999 and called it The Cradle of Humankind World Heritage Site The Fossil Hominid Sites of Sterkfontein, Swartkrans, Kromdraai, and Environs. This includes archaeological sites at Sterkfontein, Kromdraai, Swartkrans cave, Coopers B, Wonder Cave, Drimolen, Gladysvale, Gondolin, Plover’s Lake, Haasgat, Bolt’s Farm and Minnaar’s caves. The Sterkfontein caves are the best known because Professor Raymond Dart found the skull of an adult Australopithecus africanus there in 1947. There are about 25 more sites in the area that can be excavated.
For a list of all the World Heritage site visit: whc.unesco.org
To visit our feature on South Africa's UNESCO Heritage Sites click here.
The Sterkfontein Caves
The caves are about 10km from Krugersdorp on the Isaac Edwin Stegmann Reserve and part of it is open to the public. The Stegmann family donated the caves to the University of the Witwatersrand.
The first people to explore the caves were lime prospectors in the 1890s. They noticed bone fossils but they didn’t report it and in 1936 some students under Professors Raymond Dart and Robert Broom rediscovered the fossils. They were very excited and when their teachers also visited the caves the real study of the fossils began. They found many hominids, but World War II stopped the work until 1946. Professors Broom and Dart and John Robinson returned to Sterkfontein and in 1947 they found Mrs Ples.
The longest archaeological dig in the area started in 1966 and is still continuing. Professor Philip Tobias (1966 to present), Doctor Ron Clarke (1966 to present) and Mr Alun Hughes (1966 to 1991) have found about 500 more hominids and about 9 000 stone tools they used.
Other sites in the area
The first strong and healthy fossils of an ape-man man were found at Kromdraai in 1938 and Coopers B also held a part of the face of an ape-man. Drimolen is the newest of all the sites and 30 examples of ape-men have been found there. The Wonder cave being excavated at the moment in 2004 is also expected to hold a wealth of archeological evidence.
Gladysvale has produced hominids, fauna (animal) and plant remains that are 3 million years old and at Bolt's Farm archaeologists found microfauna that is older than 4.5 million years. Plover’s Lake has a large amount of animal remains that are about 1 million years old. At Haasgat there are fossils of monkeys that lived in the forest nearby about 2.8 million years ago. 90 000 fossils have been found at Gondolin since 1979. Proof of the earliest use of fire, about 1.3 million years ago, has been found at the Swartkrans cave and Minnaar’s caves have been chosen as a possible site for hominid fossils.
The Sterkfonten landscape was chosen as a world heritage site because it shows how humans and nature have existed and changed over millions of years. It is a source of heritage for the whole world and is a very large and scientifically important site for uncovering the mystery on the earliest ancestors of the human race.
Early Hominid discoveries in East Africa Where in east Africa do we find fossils of hominids? Hadar
In 1974 Donald Johanson and Tom Gray discovered nearly half of a 3,2 million year old skeleton at Hadar in Ethiopia. This was rare because most fossils are very small and generally not very complete. Johanson nicknamed the skeleton Lucy, after the Beatles song “Lucy in the Sky with Diamonds” because it was female. She was about 25 years old when she died, only weighed about 28 kg and was 107 cm tall.
Lucy belongs to the Australopithecus afarensis species of hominids and more fossils from 13 skeletons were found close to hers. Johanson called this group “The First Family”. It seems that the 13 were killed in a flash flood and are the first examples of a species this old living in a group.
In 1976 Andrew Hill, member of a team of archaeologists led by Mary Leakey, discovered a row of footprints in Laetoli, Tanzania, while throwing elephant dung at a co-worker. These footprints are special because they are about 3,5 million years old and because they prove that hominids walked on two legs at the time.
How did the footprints get there and to whom do they belong?
The Laetoli footprints were formed accidentally as a result of a volcano called Sadiman erupting and leaving a layer of ash on the ground. This was followed by a soft rainfall and more ash from the volcano, which made the ground like cement. Two hominids walking side by side crossed a muddy patch and left an 80m trail. Most of the site was excavated in 1978 along with the footprints of small animals and birds.
The hominid prints are very close to modern humans' and, because the only other hominid fossils in the area are from the Australopithecus afarensis like Lucy, must be from this species. It seems that the smaller set of footprints are deeper on the one side than the other, which means that the creature, possibly a female, was carrying something, maybe a baby, on her hip.