The man who died half a million years ago

n a gravel pit at Boxgrove, just outside Chichester, the remains of a man have been discovered, half a million years old. Only a shin bone and two teeth were discovered, but his position, under thick layers of gravel show that he is the oldest 'man' so far discovered in Britain.

The discovery was made in a gravel quarry. The gravel was laid down in a later Ice Age on top of a chalk bed, which is visible in the upper squares. Originally a stream flowedfrom the cliffs and around this stream, numerous remains of animal bones were found, and also numerous handaxes - and part of a human skeleton.

The most famous discovery - a tibia, or shin bone from an early man discovered in May 1994 after 10 years of excavation. Both ends have been gnawed off, probably by a wolf, but it was from a robust individual, very active, and is assigned to the group known as Heidelberg man.

All the measurements taken from the shin bone are at or beyond the upper end of the range determined for modern man (these details are in Nature 1994). Consequently, Boxgrove Man is reconstructed to be powerfully built individual over 6 feet tall. He is said to be a representative of Homo heidelbergensis.

As far as life-style is concerned, the evidence suggests he was a hunter-gatherer: the site is rich in animal bones which are thought to have been slaughtered by man for food.

Two teeth were also discovered at the bottom of the channel, at least a metre lower than the tibia. The teeth probably come from the same individual, and are similar to the teeth from Mauer man. The first tooth, found on August 24th by a student archaeologist, has a buildup of tartar around its base and shows signs of root damage and periodontal disease. The inference is that severe toothache was a problem for the individual concerned.

This is one of the flint handaxes found at Boxgrove.

This shows very clearly the 'tranchet' tip: a blow had been struck at the top left corner removing a flake from the top quarter of the axe, thus leaving a razor-sharp edge. Over 250 of such hand axes were found in a single season. The associated fauna - notably some voles' teeth, show that the site is to be dated to a period before the 'Anglian' or 'Great' ice age, and should therefore be around 500,000 years old.

Archaeologists are finding stone tools - but these flint bifaces are a focus of controversy. `The argument is that these things may not be human artifacts at all' says Dr Chris Stringer of the Natural History Museum. `If you look at enough pebbles, you'll see some that look as if they have been artificially shaped' (The Times, 21 June 95, page 16).

However, other archaeologists conclude differently. In a news briefing entitled `smart tools', the New Scientist reported that the Boxgrove toolmakers `were better at making tools than they have been given credit for' (5 November 1994, page 11).

An archaeological team at University College London have been making replicas of the tools and have worked out how the bifaces were prepared: initially shaping the stone with another and then refining the shape with an antler. Finally, a piece of a deer's long bone would be used to do finishing touches. The leader of the team, Mark Roberts, said that the tool-making process was evidence that Boxgrove Man and his contemporaries `were capable of planning and executing simple manufacturing processes.'

Controversy is strong on dating too - for some have suggested that Boxgrove Man is the oldest European. However, Chris Stringer points out that there are at least 10 sites in Europe claiming to be older. One of them is at Atapuerca, northern Spain.

According to the reports, the dates at this site have been fixed by reference to the vole clock.

People have examined the dental anatomy of water voles and they have changed with time. These trends, which some call `micro-evolution', are considered to occur almost simultaneously over a wide area, and in many of the sites where the dead voles are found, an archaeological date can be assigned.

A pattern has emerged, whereby the vole clock has been calibrated by reference to other dating techniques - and it is now in routine use. `Short chronologists'remain sceptical about all these other European sites - and maintain that the Boxgrove Man date should be regarded as the oldest `convincing'date for a human in Europe.

Nevertheless, even the date of Boxgrove Man has been challenged. After discussing the `notorious' difficulties of dating the Middle Pleistocene of northwest Europe, Bowen and Sykes (Nature, 27/10/94, 751) present their own estimate based on the racemization dating method. Gastropods recovered from the Boxgrove site have yielded results which `are correlated with oxygen isotope stage 11 (423,000-362,000 years before present) and thus provide an approximate age of about 400,000 years for "Boxgrove Man" - an entire ice-age younger than the previous estimate'.

However, after further discussion, they conclude `In our view, there are too many uncertainties in the various dating methods to be able to assign a definitive date for the occurrence of early hominids in the British Isles'.

Mark Roberts replied by pointing out that a variety of geochronometers have been used at Boxgrove.

Thermoluminescence techniques gave dates of 175,000-230,000 years; electron-spin resonance gave 205,000-281,000 years; uranium series methods gave a lower limit of 350,000 years; aminostratigraphy with marine species gave 303,000-524,000 years and with terrestrial species the results were 303,000-339,000 years.

`The fact is that the range of dates obtained was so varied that we used mammalian biostratigraphy, from a European database, to construct a more accurate and testable chronological model when combined with detailed lithostratigraphic data'.

Today the site is on the flat coastal plain, several miles from the sea to the south, and a mile from the low foothills of the South Downs to the north.

In 1995, English Heritage granted an additional 236,000 pounds sterling for the search, bringing their total investment in the project to over 1 million pounds - an event which has triggered much media interest. In 1995, there were excited reports of the finding of a human tooth at the site - followed by the discovery of a second tooth. Of course, no one argues seriously that these fragments all belong to the same individual, but it's a nice thought.

Half a million years ago, this site lay at the foot of chalk cliffs 200 metres high, which have since been totally eroded. Here we see the foot of the former cliffs, top left, with some of the storm beaches thrown up by the sea. When the sea level fell, a broad grassy plain soon evolved, a rich habitat for animals and early man.