THE SCIENCE OF ROMAN HISTORY: Biology, Climate and the Future of the Past

Ed. by Walter Scheidel

Princeton (2018) h/b 258pp £27 (ISBN 9780691162560)

This multi-authored book may come as a shock to many classicists. It reveals just how much scientists can add to our understanding of the ancient world. The recent work done on climate and dendrochronology is known to many, at least in outline. The work done on archaeobotany, zooarchaeology and ancient DNA (‘aDNA’) is perhaps less familiar.

The first section of the book is a reconstruction of the Roman climate. Data for this exercise come from tree rings, ice cores, stalactites, the retreats or advances of Alpine glaciers and the sedimentary layers of lakes. A series of 7,284 oak trees from north-eastern France, north-eastern Germany and south-eastern Germany allows reconstruction of rainfall patterns over the last 2,400 years. Analysis of 1,089 stone pine trees and 457 larch trees in the Alps supplements that information The causes of climate change over the centuries include volcanic activity, variations in solar activity and oscillations in atmospheric pressure.

The picture which emerges from all the above sources is that there was a warm period from about 200 BC to AD 150. The cognoscenti call that the ‘RCO’ (Roman Climate Optimum). This warm period coincided with the high point of Roman imperial expansion. The favourable climate may possibly be one of the reasons for the growth of the Empire. During the turbulent third century, the weather became a bit chillier. Some warming occurred in the north-western part of the Empire during the fourth century. Although not mentioned in the book, that was of course the golden age of villa culture in Britain. There was a sharp cooling in the early sixth century, which was probably caused by a massive volcanic eruption in the tropics. That eruption can be inferred from ice core evidence, tree rings and other proxies. Procopius, the sixth century historian, provides corroboration. He described a sun without brightness and a summer without warmth. These events ushered in the ‘LALIA’ (Late Antique Little Ice Age).

The discussion of archaeobotany is focused upon explaining the scientific methods used, rather than drawing general conclusions. As the author of that section explains, we can learn much by analysing the five phases of food. These are: production, distribution, preparation, consumption and disposal. The techniques available include analysis of stable isotopes and aDNA. This enables us to trace where particular vegetables and fruits came from and how they spread across the ancient world. We can also trace the activities of pests. Grain pests, for example, were a serious problem in Britain. They thrived in poorly ventilated granaries and in grain that was damp when put into storage. These little brutes arrived in Britain at the time of the conquest. There is much evidence of their nefarious activity in London and York.

Provisioning the army along the frontiers of the Empire was a substantial operation. It is possible to identify the supply routes. Supplying the specialist work forces at mines and quarries was even more challenging. There were two quarry settlements in the Eastern Desert of Egypt, some seven days travel from the Nile Valley. These provided marble for imperial building projects such as the Pantheon. Archaeobotanists have established that the workers in those grim quarries were well nourished and enjoyed a wide variety of fruit, vegetables, breads and so forth. More generally the Roman Empire generated a major growth in the long-distance trade of foodstuffs.

Zooarchaeology is the analysis of faunal remains. Radiocarbon dating of bones is now becoming a more precise science. It brings some surprises. For example, radiocarbon dating of cattle bones found beneath the decumanus maximus in Carthage indicates that the animals were slaughtered in the late ninth century BC. This suggests an earlier date for the foundation of Phoenician Carthage than suggested by pottery finds. Greek late geometric pottery recovered from that site has been dated to the late eighth century. 

Zooarchaeological data of this kind, taken in isolation, does not tell any ‘story’. But when zooarchaeological data are added to other sources, both literary and archaeological, they help to build up a complete picture of what was happening in the ancient world. Analysis of teeth is a pointer towards age at date of death.

An intriguing section explains the different methods of estimating stature from skeletal remains. The old-fashioned approach, established in the late nineteenth century, was to calculate height from bone length. That is far too simple for modern zooarchaeologists. They now use the ‘anatomical method’, to make allowance for soft tissue, in conjunction with regression formulae. They have done detailed calculations on 76 well-preserved skeletons from five late Roman cemetery sites in southern and eastern England. The upshot is that men were about 5’ 5” tall and women were about 5’ 1” tall.

The analysis of aDNA provides a graphic picture of the cosmopolitan nature of the Roman Empire. The most comprehensive study so far undertaken relates to seven genomes of Romano-British people from York. Six show close affinities with modern British Celtic populations. The seventh shows affinities with populations from the Middle East.

This book is essential reading for the professional classicist. Also, it has much to offer any general reader of the classics, who wishes to look beyond the familiar and well-loved sources. Work is going on far away from classics library, across many branches of science. This fascinating book will help the reader to catch up with all that research in the space of a few hours.

Rupert Jackson

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