The origin of man and the location of our earliest ancestors became a matter of prestige with considerable political impact, not least in terms of expressing a strong nationalism. The first fossil finds of early human-like beings were found in Asia, and consequently it was believed for a long time that Asia was the cradle of mankind. The first discovery was made in 1892 by Eugène Dubois who, during excavations on Java, found a prehistoric cranium with obvious human characteristics – ‘Java Man’– who was long believed to be the missing link between monkey, ape and man. In 1929, a similar discovery was made by the Swedish scientists Otto Zdansky and Birgitta Bohlin, this time in the Zhoukoudian cave outside Beijing –‘Peking Man’. Today we know that Java Man, as well as Peking Man, belonged to the species Homo erectus, ‘the upright-walking man’, an early member of the Homo family who had migrated from Africa to Asia a million years ago but who later disappeared in competition with Homo sapiens – ‘the thinking man’ – who migrated out of Africa much later.

However, in the western part of the world, people were quite confident that Europe was the cradle of mankind, and several finds of prehumans were presented from various parts of the European continent: skulls of Neanderthals were discovered in 1856 in the Feldhofer cave in Neanderthal in Germany. The Neanderthals were long believed to belong to our own species, Homo sapiens. Today we know that the Neanderthals constituted a specific line within the Homo family and that they in fact were descendants from a much earlier species, Homo heidelbergensis, which existed about half a million years earlier and was also a common ancestor of our own species, Homo sapiens. The French reported about the Cro-Magnon man after finds of human-like skeletons in Cro-Magnon in 1868. Today we know that the Cro-Magnon man represented early immigrants from Africa to Europe about 30,000 years ago.

But from England there were still no reports of early human beings. A good illustration of the desperate search for early humans in England is the discovery of the ‘Piltdown man’, described by the British researcher Charles Dawson in 1912. He presented well-preserved fragments of a human-like skull: a lower jaw and a couple of molars that he had found in a gravel pit in Piltdown and that he felt proved that Britain was the cradle of mankind.

However, it was ultimately found that the Piltdown man was a clever bluff. The skull was composed of a contemporary human cranium and a jaw from a chimpanzee where the sharp teeth had been ground down to make them look more human. This discovery was regarded as the scandal of the century in the field. We never learned who the forger was, even if the man behind the discovery was strongly suspected.

By tradition it was impossible for anyone to believe that Africa was the cradle of mankind, and it took a long time before such a concept could be accepted by the palaeoanthropologists. However, a series of fossil finds in the beginning of the twentieth century led to a total re-evaluation of the old concepts, and today it is generally accepted that Africa is the continent from which our early ancestors once emerged.

However, our evolution is not a long, unbroken line but rather a large number of ‘evolutionary experiments’ where several parallel developmental lines appeared and disappeared like an irregular bush with numerous sprawling branches, some of which end blindly and abruptly.

In 1924, a sensational finding in South Africa radically changed our view on the origin of man. In Taung, near the diamond city Kimberley, the Australian scientist and anatomist Raymond Dart found a skull with an appearance no one had seen before: an apelike cranium with obvious human characteristics like small canines but with a skull that could have hosted only a very small brain with a volume of 450 cc, about one-third of the brain of a modern human being. Strangely enough, the foramen magnum, the big hole in the skull, indicating a passage of the spinal cord into the skull cavity, was located at the bottom aspect of the skull, indicating an upright posture. The sutures of the skull bones were not yet fused, indicating that it was a child’s skull. The find, which has been dated to 2.6 million years ago, indicated for the first time a possibility that man may have originated in Africa. The controversial discovery was much debated: who could believe that Africa was the cradle of mankind? Dart named his find Australopithecus africanus – the ape from the southern part of Africa. This and other similar finds from South Africa from the same time period indicated that our earliest ancestors were two footed and walked upright at a time when the brain was still very small – a totally new concept.

This observation was reinforced 50 years later when, in 1978, Mary Leakey made a sensational discovery in Laetoli, Tanzania – a 27-m-long track of footprints from upright-walking individuals who had walked over an area of flatland covered with volcanic ash that had solidified, preserving the footprints [13–15]. Probably two grown-up individuals and a child had moved across the landscape together. The footprints dated to 3.7 million years ago and seemed more or less identical to human footprints, with imprints of the arch of the foot and the big toes that (in contrast to monkeys living in trees) pointed straight forwards, parallel to the other toes (Fig. 2.2). The footprints, which indicated a human way of walking, have been associated with hominins of the type Australopithecus afarensis, among which ‘Lucy’ is the most well known.

In 1974, Donald Johanson and his associates made a sensational find in a dried river bed in the Hadar desert in Ethiopia – a large number of skeletal fragments from one single prehistoric individual. The group found pieces of bones from the upper and lower extremities, vertebral column, ribs and pelvis together with sparse hand bone fragments. For the first time, the finds made it possible to put together a fairly complete skeleton of one unique individual: a prehuman who lived 3.2 million years ago. The find was named Australopithecus afarensis, ‘the southern ape from Afar’ [1].

In the research camp, the staff worked for several days putting together the parts of the skeleton, a tedious process accompanied by the Beatles tune ‘Lucy in the Sky with Diamonds’ – a good reason to name the find Lucy. Together with several similar finds from the same area, it now became possible to approximately reconstruct a hominin – a bipedal prehuman – who had lived in the area several million years ago. It has been concluded that Lucy was upright walking, but later analysis of fossilised scapulae supports the hypothesis that her locomotor repertoire included a substantial amount of climbing [16]. Lucy measured little more than 1 m in height and had a very small brain size of about 400 cc, like a chimpanzee’s brain. Today Lucy is preserved in the National Museum of Ethiopia under the domestic name Dinknesh (wonderful) [10].

How well-developed were Lucy’s hands and what could she perform with them? The hands of early tree-living apes were adapted for a life in the trees: the fingers were long, slender and a little bit curved to create an effective grip around tree branches, while the thumb was rudimentary, short and fairly nonmobile. Many of these finger characteristics were found in Lucy’s hand, but in contrast to earlier tree-living apes, the hand had a well-developed and very mobile thumb with ‘opposition’ abilities; the thumb could be moved in a counteraction across the palm of the hand against the other fingers [7, 10, 17–20]. A prerequisite for this function is a saddle-shaped joint at the base of the thumb. Thus, Lucy probably had very good gripping function in her hand with a high degree of precision in fine motor movements. However, Lucy probably lacked the capacity to cup the hand, which is a crucial ability of the human hand for really good hand function. It was not possible to make a full and detailed analysis of Lucy’s hand as there were only sparse bone fragments from a few fossil hands to study.

Among several important characteristics in Lucy’s arm were the ability for flexion and extension in the wrist joint and the capacity to rotate the forearm inwards and outwards (pronation/supination) [21]. These forearm abilities were probably a prerequisite for throwing stones with precision and for gripping and using primitive weapons for defence and in fights. The mobility in the forearm, wrist and thumb are qualities that would make it possible for the hand to make and use tools, provided that the mental resources were sufficient. But the perception has been that Lucy, with her small brain, did not have this capacity – the hand was certainly developed into an instrument of great precision, but there was still no effective superior control organ – a well-developed brain. No handmade tools have been found from Lucy’s time period, but in August 2010, Nature presented new finds indicating that hominins from Lucy’s time actually seem to have used simpler stone tools to scrape and discard meat from carrion bones and to crush bone to access the bone marrow [22]. It is difficult to determine whether these stone tools were spontaneously found stones of suitable shape in the immediate vicinity or if they have been purposely made by hand. The tools were discovered only 200 m from where a fairly complete skeleton of a girl belonging to the species Australopithecus afarensis – Lucy’s baby – was found [23] in Dikika, just 4 km from where Lucy turned up. These new finds have attracted much public attention since they suddenly shift the established time table for use of tools by our early ancestors back about 800,000 years. According to current belief, so far the earliest use of stone tools to handle the meat and bone of animal carcasses took place 2.5 million years ago, a dating that is based on finds in Gona, Ethiopia.

‘Lucy’s baby’ was named Selam – meaning ‘peace’ in several Ethiopian languages – in hopes of encouraging harmony among the warring tribes of Afar [24]. The skeleton, judged to be that of a 3-year-old girl, consisted of a virtually complete skull, the entire torso and parts of the arms and legs. Selam had legs built for walking and long curved fingers built for climbing, indicating that she was suited to an arboreal existence but also well adapted for walking on the ground.

Recent fossil finds in Ethiopia have shown that Lucy might have been just one of two or more parallel developing lines existing at the same time. Based on bone specimens from a foot, it has been concluded that another species, able to walk upright but also spend much time in trees, existed during the same time period as Lucy [25].

For a long time Lucy was regarded as our ‘first mother’ in the development towards our own species Homo sapiens. But with the 2009 presentation of Ardi – Ardipithecus ramidus – it became necessary to re-evaluate and reappraise the earliest development of man. Tim White, professor of Integrative Biology at the University of California in Berkeley, and his team spent 15 years analysing and reconstructing skulls, teeth, pelvic bones, hands, feet, arms and lower extremities from at least 35 individuals who lived in northeast Ethiopia 4.4 million years ago, not far from the area where Lucy was found in 1974 [2, 3, 26]. Among the finds were several very well-preserved skeletons, and for the first time it became possible to reconstruct in detail complete skeletons of one of our earliest ancestors.

The summarised finds were presented in 11 articles in the same issue of Science. Ardi’s skull hosted a brain with a volume of 300–350 cc [27], that is, a brain considerably smaller than Lucy’s. The anatomy of Ardi’s pelvis, lower legs and feet indicated that she had an upright posture and an upright way of walking [28]. She measured 120 cm in height and her weight was about 50 kg. The feet were big and well adapted for upright walking, but Ardi also had a deviated big toe, which was useful for life in the trees [29]. Thus, she was probably adapted for a life in trees as well as on the ground. Her canines were small and not at all as big as those of chimpanzees, indicating a more human-like and less aggressive character.

Finds of wood fragments and seeds indicate that Ardi lived in a landscape dominated by sparsely growing fig, elm and palm trees. A large number of fossils from animals such as porcupines, hyenas, bears, rhinoceroses, pigs and elephants were found in the same area. Ardi was probably an omnivore with a preference for fruits, mushrooms and small animals [29].

Ardi’s arms were long and slender and reached knee level [3]. Her hands were very mobile with an anatomy adapted to a life in the crowns of trees: a very flexible wrist and long, slightly curved fingers with a good capacity for effective gripping around branches. But Ardi’s hands also had good precision capacity and good fine motor functions, exhibiting several of the characteristics also found in Lucy’s hand 1.2 million years later (Fig. 2.3). Ardi’s thumbs were well-developed and opposable, indicating a very good hand function [2, 3]. The anatomy of the hand bones showed that these individuals did not support the weight of their bodies on their knuckles when they walked: they were bipedal and moved in an upright position.

With the discovery of Ardi, our views on our earliest ancestors changed dramatically. It was long believed that the human line had passed a ‘chimpanzee phase’, but Ardi does not show any similarities to chimpanzees; instead she was characterised by several primitive features reminiscent of even earlier non-human primates. This means that Ardi must have belonged to a species that appeared soon after the stage about 6–7 million years ago when the developmental line split into two branches: one that further developed towards chimpanzees, while the other constituted a ‘human line’ leading to Ardipithecus ramidus and ultimately to our own species, Homo sapiens.

Ardi was perhaps our original ancestor – upright walking with a well-developed hand and a long and moveable thumb, but still with a rudimentary brain. However, Ardi may have belonged to only one of several parallel developing lineages, and today no one can say for sure which of these lines ultimately led to Homo sapiens. Either way, the foundation was laid for a continuous interaction between hand and brain over the ensuing several million years, with the brain developing towards capacities like abstract thinking, tool making and, with time, communication via symbols, pictures and ultimately a sign or spoken language.

An article in Science, published on 18 December 2009, proclaimed the discovery of Ardi ‘The Breakthrough of the Year’ [30].

Mary and Louis Leakey carried out extensive excavations for several decades in their search for human fossils on the shores of Lake Victoria and in Olduvai Gorge in Tanzania. They found a large number of fossils from several types of extinct animals. But most of all they were hoping to find traces of our earliest ancestors. On 17 July 1959, the search was successful. At the time Louis was ill, so Mary went on a tour around the area herself. Suddenly she sighted some bone fragments that looked interesting, and upon closer inspection they turned out to be two big canines of an early hominin. This was the first find of Australopithecus (Zinjanthropus) boisei, which has been dated to about 1.75 million years ago [31]. Anthropologists named the find Zinj. The very powerful molars indicated a diet consisting of fruits and nuts – consequently the hominin got the nickname nutcracker man. The find, which received much attention, resulted in renewed financial support from the National Geographic Society, making further excavations in Olduvai Gorge possible. Still, the Leakeys were hoping for fossils from our own genus Homo.

In 1962, the Leakey couple reported new spectacular finds in Olduvai Gorge. This time they reported four skulls of less primitive appearance, with a larger skull cavity that could host a larger and more developed brain than earlier finds of Australopithecus – about 640 cc. They also found a lower jaw and several hand and foot bones. At the same location, they found a simple type of stone tool: fist-sized round stones that had been sharpened by striking several sharp flakes from the sides of the stone. The sharp edge of these ‘pebble choppers’, as well as the edges of the flakes, was probably very suitable for processing meat and cutting the skin of animals, while the larger stone would easily crush bones to access the bone marrow. The Leakeys named this manufacturing of simple stone tools Oldowan.

The Leakeys felt that they had now found a hominin with a more well-developed brain than earlier species. They believed they had found the first individuals of a new genus – Homo – and they named the find Homo habilis, ‘the handy man’.

The finds were presented 1964 in Nature with the prestigious title ‘A new species of the genus Homo from Olduvai Gorge’ [32]. Louis Leakey strongly argued that he had now found a fossil of the first real human being. It was felt that Homo habilis, dated 2.4–1.6 million years ago, probably had its origin in some species of Australopithecus. Homo habilis’ weight has been estimated at about 24 kilos.

The hand of Homo habilis was characterised by long, slightly curved finger bones where the most distal bones (end phalanges) in the fingers were broad and human-like. Like Ardi and Lucy, Homo habilis had a relatively well-developed thumb that was opposable, an important property giving the hand great precision and a good gripping function [6, 33–35]. Even if Ardi, 2 million years earlier, already had a well-developed hand, the researchers argued that Homo habilis was the first hominin who – with its more developed brain – possessed sufficient capacity for planning and abstract thinking to fully utilise the hand in making tools. However, these conceptions are now being questioned, since evidence has recently been presented showing that the earlier species, Australopithecus afarensis, might also have been able to make simple stone tools (see also Chap 3).

Lucy and her ancestors were probably very ape-like, and Homo habilis probably did not look much different. The big change came with the succeeding Homo erectus, who had a much more human-like appearance. Homo erectus was believed to exist 1.8 million–300,000 years ago. While earlier species had relatively long slender arms, short bones and a curved posture, Homo erectus was more human-like and tall with longer legs and more upright walking. Many of modern man’s typical characteristics were present in Homo erectus [10]. The brain had undergone an explosive development, and the posture of the body was more like modern man. ‘The boy from Nariokotome’ in Kenya is one of the most well-preserved fossils of Homo erectus, probably 1.6 million years old. The boy from Nariokotome never reached puberty, but as a grown-up he would probably have been more than 180 cm tall and weighed about 68 kilos. This means that our ancestors, in a period of just 100,000 years, underwent an explosive development and became almost three times as big as the small Homo habilis.

Recently discovered footprints of Homo erectus in sedimentary layers close to the city of Ilere in northwest Kenya, probably about 1.5 million years old, show that the feet of these individuals were anatomically more or less identical with modern man’s feet, with high arches and big toes pointed straight forwards, parallel to the other toes [36, 37]. The tracks of the footprints also show that Homo erectus had an efficient way of walking, corresponding to modern man, with the heel obviously lifting while the front of the foot was still on the ground. The footprints indicate a more developed anatomy in a ‘modern’ direction as compared to the footprints of Australopithecus afarensis, which had previously been found in Laetoli, Tanzania, and are estimated to be 3.7 million years old. Probably the well-developed feet of Homo erectus contributed to an improved walking capacity, making the very long migrations characterising this species possible: Many of these individuals emigrated from the African continent.

Fossils of skulls show that Homo erectus had small canines and a considerably larger brain volume than its predecessors, about 1,000 cc. Researchers found more advanced tools close to Homo erectus fossils than those found near older fossils of hominins: so-called hand axes, that is, oval or pear-shaped stones where flakes had been symmetrically knocked off from both sides to achieve a sharp cutting edge. These activities were named Acheulian (after Saint-Acheul, a suburb of Amiens in northern France where some of the first finds were made). Acheulian hand axes were processed with stones, horn, bone and wood to get their final form and sharpness. They were a general-purpose tool that could scrape, cut and stab skins of wild animals preparatory to skinning [6]. Tools of this type have been found in Africa, Asia and Europe. It is generally agreed that the hand axe was an extension of the pebble chopper associated with the Oldowan culture. From originally being very primitive in appearance, over time hand axes became increasingly sophisticated, probably reflecting a corresponding development towards more advanced thinking and an improved aesthetic sense of form and decoration.