INTRODUCTION

This chapter is concerned with the palaeoenvironmental implications of Quaternary insect faunas, in particular with the ways in which species responded to the large scale climatic events such as the glacial/interglacial oscillations that are such a characteristic feature of this period. These climatic events are probably as near to global changes as any yet documented in the geological timescale, and the manners in which insect species responded to them may well have global significance.

The Quaternary offers a number of unique opportunities for understanding the ways in which organisms responded in the past, and might be expected to respond in the future to such widespread climatic changes. First, this period experienced some of the most numerous, widespread, intense and rapid climatic changes that have yet been recorded, oscillating between prolonged episodes of glacial severity and shorter interludes of temperate conditions (i.e. interglacials, such as the one in which we are living now) some of which were rather warmer than those of today. These varying climatic conditions had to be met by a flora and fauna that was, to a large extent, made up of the same species that are living today with apparently the same environmental preferences and limitations as those of their present-day representatives. Thus the Quaternary (approximately the last two million years) has a good claim to be the most relevant of geological periods in any discussion about current global climatic changes and their possible effects on the modern biosphere.