Introduction

This chapter has three aims:

(1) To compare the extent of tool-use across living apes;

(2) To relate variation in tool-use by homology to phylogenetic relationships and by analogy to variation in other features;

(3) To synthesise these findings so as to infer aspects of tool-use by ancestral hominoids that have implications for understanding the origins of material culture.

Each aim is a further step removed from the data.

The first aim entails updating of the evidence, as new findings on tools used by apes continue to mount. More and more it is clear that context is important: how an organism behaves in captivity may or may not reflect its actions in nature. Here, the exercise shows not only the state of play but also persisting gaps in knowledge. Many question-marks remain about the tool-use of even these well-studied mammals.

The two parts of the second aim present different problems. The fossil record for apes is minimal. Molecular anthropology now provides a wealth of data for tackling phylogeny, but the conclusions do not always agree (Miyamoto et al., 1987). Evolutionary relationships among the African Pongidae and Hominidae remain unresolved, although a consensus seems to be emerging (Goodman et al., 1990). In arguing by analogy in terms of anatomy, individual abilities and socio-ecology, the difficulty is in choosing the right variables to the right degree of specificity.

In undertaking the third aim, this chapter starts from the simple premise that each mode in the phylogenetic tree represents an ancestral hominoid.