This chapter concentrates on the death date, the date after which Proto-Indo-European must have ceased to exist. But it helps to begin by considering how long a period probably preceded that. Given that the time between the birth and death dates of Proto-Indo-European could not have been infinite, precisely how long a time was it? Do languages, which are living, changing things, have life expectancies?My attention was drawn to this by a very positive review from none other than Lois McMaster Bujold back in 2009 on her Myspace blog (the review is now lost, alas, due to Myspace deleting it).
It is a very detailed presentation of evidence supporting a theory that I have known about for a long time: that Proto-Indo-European, the long-lost language from which most European languages, most Indian languages and others (notably Farsi) are descended, was originally spoken by tribes living on the steppe between the Black Sea and the Caspian Sea, around 3500 BC. There's a well-known set of arguments for this which starts from the vocabulary which can be reconstructed: their language had words for birch, otter, beaver, lynx, bear, horse and bee and honey (these last significant because apparently you don't get bees east of the Urals). The fact that they had a whole vocabulary dealing with wheeled vehicles, and also sheep with wool (woolly sheep only appear after 4000 BC, whether due to mutation, artificial selection or both) also sets an archaeological time horizon.
Anthony turns this linguistic evidence into a sequenced story of technological innovation: the domestication of sheep and cattle, then horses, then the development of agriculture and towns, and then the invention of wagons and war-chariots. This was enough to give the people of the steppes using this technology a decisive edge as they settled the fertile but hiterto unfarmed uplands and valleys of Europe and Southwest Asia. This is supported by a wealth of archaeological evidence from excavations in Russia over the last few decades, several conducted by Anthony himself. (I confess I skimmed the detail of the digs; I worked on two archaology sites in 1984-85, which was enough to scratch my itch for life.)
I've always found the idea of reconstructing a dead language romantic and fascinating, but this book really scores by making firm arguments based on archeaology and documentation (such as the Rig Veda) which all support the conclusion. He also looks at when and where the daughter languages might have plausibly split off to form their own groups, though not in detail. The early history of Germanic languagues is still a bit mysterious. But it's a fascinating book, which left me with admiration for what we can find out, but also awareness of how little we can ever know about the lives of our ancestors thousands of years ago.