BOOK REVIEW / Ancestral manoeuvres in the dark: The Neandertals: Changing the Image of Mankind - Erik Trinkaus and Pat Shipman: Cape, pounds 20

EVER SINCE the first Neanderthal remains were discovered in 1856, three years before the publication of Darwin's On The Origin of Species, these shadowy figures have fascinated and repelled us. The Neanderthals lived in Europe through the icy times from about 100,000 to 35,000 years ago. They shared many human characteristics, but differed in their stubby physiques, immense strength and beetling brows. In addition, even though they had brains as big as our own, they seem not to have been very bright, developing only rudimentary tools, and no boats, needles or cave-painting.

A common early response dismissed the Neanderthal fossils as the remains of diseased or pathological humans. But even after the spread of evolutionary ideas won them recognition as a genuine extinct group, few people welcomed the idea that we were descended from this race of prehistoric prop forwards. This is why the Piltdown forgery, arguably the greatest hoax of all time, was swallowed so enthusiastically by the anthropological establishment, which for the first half of this century hailed a modern human cranium and an orangutan jaw as the relics of Eoanthropus - dawn-man. The forgery was cleverly done, but it would not have remained unchallenged for so long if the experts had not been so eager to find us some more prepossessing ancestors than the Neanderthals.

The Piltdown story is just one of many episodes recounted by Erik Trinkaus and Pat Shipman in their survey of just about everything that has ever been said about the Neanderthals, from the discovery of the original fossils in the Neander Valley near Dusseldorf to the most recent academic debates. This is a detailed work of historical scholarship, but it also tells an exciting story, in which biographical sketches of a large cast of controversialists leaven a mass of information about fossils, strata and spelling (the authors explain that nobody, except the British, still spells Neanderthal with an 'h'- Tal is the German for valley.

As one might expect, attitudes to the Neanderthals have often kept step with wider ideological movements. When, after the Second World War, Unesco condemned racial divisions as scientifically insignificant, the palaeoanthropologists followed suit by lumping many previously distinguished fossil groups into a small number of different species. There were disagreements about exactly where to draw the lines, but few demurred at the inclusion of the Neanderthals in our own species of homo sapiens and many accepted, in an enduring image from this period, that a properly shaved and dressed Neanderthal could happily have passed for human on a New York subway.

Somewhat paradoxically, however, being nice to Neanderthals can mean being nasty to living races. If you think that living Europeans are descended from 100,000-year-old European Neanderthals, then you have to move back by quite a long way the date when Europeans last shared ancestors with non-Europeans. This line of thought was taken to its logical conclusion in the 1960s by the patrician East Coast American anthropologist Carleton Coon, who held that the human races diverged more than half a million years ago and have been keeping themselves pure ever since.

Coon's views attracted political opprobrium in the 1960s, and recent scientific evidence has supported this verdict. In particular, DNA analyses of existing peoples have suggested a fairly recent date for their divergence, which would imply that Europeans are descended not from the Neanderthals but from later invaders who drove the Neanderthals to extinction. The DNA analysis is controversial, however, and Trinkaus and Shipman are less than fully convinced. They don't want to return to Coon, but they do argue that the Neanderthals would at least have interbred with the modern invaders to create a distinctive European ancestry. However, even this seems a somewhat eccentric interpretation of the data, notwithstanding Trinkaus's undoubted status as a leading expert on Neanderthal fossils. Even if the invaders were biologically capable of mating with the Neanderthals, which is highly doubtful, would they have wanted to? Given the extreme cultural and physical differences, one would have thought that inclination and prudence alike would have acted as strong anaphrodisiacs.

Of course, these questions ought ideally to be decided by evidence, not ideology, and it should be said that the authors of this book never suggest otherwise. But evidence in palaeoanthropology is hard to come by, and inferences drawn from old bones are notoriously fragile. In a current issue of Nature and too late for this volume, there are reports of fossils from Spain which indicate that the Neanderthals started diverging from other hominids as much as 300,000 years ago. If this is right, it will be even harder to find them a place among our ancestors. But no doubt those who want to will find some way of accommodating even this new evidence. If one thing is sure in this area, it is that controversies about the Neanderthals will not die out for some time.