Each manuscript in this volume brings back to me the memory of a scene I witnessed with A. Suzuki in 1965. We were in western Tanzania, 50 km east of the escarpment in no man's land, when we came across an orderly procession of 43 chimpanzees, marching across the Miombo woodland with scarcely a leaf left on the boughs in the dry season (Itani & Suzuki, 1967).

It seems now that everything we must know about chimpanzees was condensed and suggested in the procession we witnessed, but we were unable to decipher the mystery at that moment. The manuscripts in this volume may present the possible answers for those who read this book; and this must have been the reason the manuscripts made me hark back to the scene of 30 years ago.

It was Thomas Huxley (1863), who first articulated the prologue to a plausible scenario recognizing the significance of great apes, especially the importance of inquiring into their relation to the human species, in the first chapter of Evidence as to Man's Place in Nature.

Later, well into the twentieth century, the first milestone was laid along the path towards the composition of a comprehensive scenario on the relationship between humanity and the apes. The milestone was The Great Apes by Robert & Ada Yerkes (1929).

INTRODUCTION

Until 1987, the received wisdom in psychobiology was that laterality of function in Homo sapiens was unique, and so qualitatively different from all other species, including even our nearest relations, the great apes. Humans were said to be overwhelmingly right-handed at species (or population) level, that is, about 90% of persons show right-hand dominance for virtually all kinds of hand-use. In contrast, other hominoids were said to be randomly lateralized, either showing no consistent, overall preference for left or right, or being individually lateralized to either the left or right side in about equal numbers.

The published data available on apes at the time seemed to support these views of 50 : 50 randomness, but findings were sparse. Finch's (1941) benchmark study showed a population of 30 chimpanzees in which all but one were lateralized, but to an equal extent for left and right.

The Great Apes, in Africa and Southeast Asia, are endangered. My expertise relates to chimpanzees, and so I will concentrate on them and on forest conservation in Africa. In most cases, the same issues also apply in the conservation of bonobos and gorillas. At the turn of the century, there were hundreds of thousands of chimpanzees living in what are now 25 African nations throughout a more or less unbroken belt of forest from the far west coast of Africa to the eastern shores of Lake Tanganyika. There are still many chimpanzees in the area that was the heartland of their historic range – in the contiguous forests of Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon and Zaïre. There are still vast areas of forest in some of these countries. But for how much longer? Forests and woodlands worldwide are disappearing as a result of commercial logging and the ever-increasing growth of human populations that tend to compete with and to destroy, rather than to live in harmony with, the natural world. When an area of forest is despoiled, the chimpanzees who live there disappear too: the territorial nature of wild chimpanzees ensures that communities squeezed out by habitat destruction cannot easily integrate with others, away from the devastated areas. Chimpanzees have already become extinct in four of the nations where they once lived and their numbers have shrunk alarmingly in many others.

This book emerged from a conference, ‘The Great Apes Revisited,’ sponsored and hosted by the Wenner-Gren Foundation for Anthropological Research, and held in Cabo San Lucas, Baja California Sur, Mexico, 12–19 November, 1994. The organizers were William McGrew and Toshisada Nishida, and the monitor was Linda Marchant. But the result is much more than conference proceedings, and in the 20 months from meeting to publication most chapters went through notable transformations. For example, although only 23 primatologists took part in the conference, 40 contributed to the book.

The origins of the conference lie two decades earlier, in another Wenner-Gren conference, ‘The Great Apes,’ organized by Jane Goodall and David Hamburg, and held in Burg Wartenstein, Austria, in July, 1974. Five years later, the results were published, along with additional invited chapters, as The Great Apes (Hamburg & McCown, 1979). Of the participants in the 1974 conference, only a handful are still active in research on great apes (including the two organizers), while others have died, retired, or shifted to other interests.

The two conferences can be contrasted in several ways. In 1974, there were no papers discussed on bonobos (Pan paniscus) nor lowland gorillas (Gorilla gorilla gorilla); too little was known. All but one of the field studies of chimpanzees were of the eastern subspecies (Pan troglodytes schweinfurthit), given the lack of knowledge then of the other geographical races in central western (Pan troglodytes troglodytes) and far western (Pan troglodytes verus) Africa.