Following many years during which all that was available was a tooth here, a fragment of skull there, datable with little accuracy, we are now confronted, it seems almost day by day, by extensive discoveries of fossil conglomerates. They often include remnants referable to several individuals, sometimes even many fragments of the same individual, and they come from a variety of geographic sites and with a wide range of determinable dates.

Such discoveries, in Olduvai and Southern Africa, at East Turkana, in the Omo, at Laetoli, in the Afar Valley, in Pakistan, in Burma, in Eastern Europe, and in several...

The primates are inevitably, and in some ways unfortunately, the most interesting of animals to that sapient species that also belongs to the Order. No other group of mammals has been studied by so many investigators and no other single living type is as wellknown as the human species. In consequence we know more about the relationships of humans to other primates, of the human place among the primates, than about most other vertebrates. The evidence upon which these relationships are grounded is extraordinarily widely based.

In spite of all of this, there is not total agreement about the classification...

Understanding anatomical fragments in the evolutionary context depends upon first obtaining information about the structural differences that truly exist and second attempting to make judgements about the biological meaning of the discovered differences. Classically, when assessment by the human eye and judgement by the human mind are the main tools involved, these two phases may not appear to be clearly separated from one another; the entire procedure may be done in one intuitive leap, as it were, a method that is nevertheless rather powerful. But as other techniques for describing and discovering structure are added to the powers of human...

Once differences in structure have been defined, as, for instance, by the methods of the last chapter, we can try to assess their biological (evolutionary) meaning. For some workers the fact and nature of structural differences are alone the result of the process of evolution, and speculation about evolution is therefore made directly. But for the great majority of biologists, discovering structural differences is merely the first step in making evolutionary assessments. As next steps, such biologists expect that variations in structure can be weighted according to whether or not there is evidence that they reflect specific biological information, such...

Studies of fore limb function in vertebrates, especially mammals, are many fewer than for the hind limb and have usually been aimed at quadrupedalism. Thus, in his consideration of quadrupedal structure using the model of a table, Gray (1968) treats fore limbs essentially in the same way as hind limbs, although it is true that he differentiates the propulsive lever from the propulsive strut and indicates that the former is more generally associated with hind limb function and the latter with fore limb activities.

And though there have been other studies of fore limbs (for example, the fore limbs of...

Leaping seems, intuitively, a very obvious behaviour. An animal, whether at rest or during movement, propels itself into the air, moves in a ballistic flight pattern and then lands. Although leaps may be upward, horizontal or downwards, although they may end in running, flight or swimming, as well as in a posture on a solid substrate, and even though some animals progress almost entirely by leaping, in most animals this is a behaviour that is additional to walking and running. The walking and running movements are usually basic; leaping is superimposed upon them. However, exactly because leaping is a simple...

Although the subject of our last chapter, leaping, is a conspicuous activity of many primates, the most general form of locomotion among primates is simple four-footed movement. And this, of course, though it may depend somewhat more upon one pair of limbs than upon the other, enjoins for the most part relatively equal participation of all four limbs. It is an activity of which all primates, save humans, are capable and which characterizes many of them, including representatives of all major taxonomic groups. Paradoxically, perhaps, primate quadrupedalism has been much less studied than the more exotic forms of primate movement,...

The studies of prior chapters have shown us several views of primate structure. Chapter 2 demonstrates that, if we look at a wide variety of anatomical features, such as external characteristics of faces, genitals, hands and feet, internal features of teeth, jaws and skulls, and varieties of pelage colours and types, we find the currently accepted arrangements of the primates. This shows the generally linear array from prosimians at one extreme, through New World monkeys, Old World monkeys, lesser apes and great apes in sequence, to man at the opposite extreme.

Chapters 5 through 7 demonstrate, in contrast, that if...

The main bulk of the multivariate morphometric studies (described in this book in Chapters 5, 6 and 7) have been aimed at analysing a variety of individual parts of primates. The question that is being asked in each case is: how do these anatomical regions arrange the different primate genera? In each case the answer seems to relate to function.

Anatomical regions and animal functions. In summary, previous chapters have shown that upper limbs (a) arrange the various primates in a band-like spectrum: those animals that use the upper limbs most in tension lie at one end of the spectrum...

For some time after their first discovery, there was a great deal of controversy about those fossils from Southern Africa and Olduvai that were ultimately designated australopithecines. Some workers assessed them as more related to the living apes, others as more closely linked with man. For many years now, however, the general consensus has been that these fossils are very close to the human lineage and that particular sub-groups, such as the gracile species or individual specimens like so-called Homo habilis, are direct human ancestors. This is the conventional idea of the single lineage indicated in the first chapter of...

Two important developments have occurred since this book went to press; they greatly increase the information available to us about two of the fossil groups most critical for understanding early human evolution. The first of these stems from a large number of newly published studies of australopithecines, mostly about the recent finds from the Afar valley in Ethiopia. The second comes from a large amount of new data on ramapithecines resulting from the recent discoveries in China.

It is true that there are still a number of new publications about australopithecines concluding that these forms show ‘a fully developed adaptation...