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John Musty's Science Diary This is the 50th issue of Science Diary, and we start appropriately by revealing the background infor­ mation about one of the most spec­ tacular recent stories, that of the discovery of 'The Oldest European' at Boxgrove. We continue with an inter­ esting thought: Ice ages can end (and presumably therefore also begin), in as little as 3 to 5 years. This is based on results from the Greenland Ice Core Project, from which we also look at the evidence from trapped methane, while further evidence for climatic changes comes from peat bogs.

the base of an ancient cliff at Boxgrove, near Chichester, West Sussex, approximately 10 miles from the present coastline. Admittedly the discovery is only part of a tibia but it was associated with stone tools (biface handaxes) and butchered animal bones (including elephant, rhinoceros, bear, wolf, deer, mink and vole). Thus its age is estimated at 500,000 years. Although the tibia is incomplete (294 mm long) its midshaft dimensions were much larger than other comparable bones, and the body weight is estimated as greater than 80 kg, which was transformed in the press into the man being 6ft 3in tall. The assumption is also made, because of the bone's robustness, that the individual i s male.

We then turn to coal mining, where Dr Ryder has found evidence for haute couture down the Coleorton medieval coal mine. Then, in a brisk change of period and place, we look at the use of magnetic susceptibility for finding out where the granite columns in Rome came from, and a note on the use of magnetic susceptibility in archaeological prospecting. We then look at residues in pots, and learn that the base sherds are not always the best place to look for residues. Finally, we salute two Nobel prize winners, and end with a useful tip on how to make $300,000,000.

The Oldest European The 'oldest European' has been discovered at Boxgrove quarry, in Sussex. This was to have been announced in an article in Nature due to be published on 26th May, and English Heritage called a press conference on May 24th to publicise this , embargoed till May 26th. However on 17th May the Times published a short article and a press conference had to be called that after­ noon, at a time when Chris Stringer, the head of Hominid Research at the Natural History Museum, and the principle author of the Nature article, was abroad.

He belongs to the category which Chris Stringer calls 'Ancient Man', that is not modern man {Homo sapiens sapiens) nor Homo erectus, but intermediate, and which he names Homo cf.heidelbergensis after the human mandible found a t Mauer near Heidelberg in 1907.

The date appears to be early, that is before the 'Anglian' glaciation in oxygen isotope stage 13, currently dated to between 524 and 478 kyr, if one believes the Milankovich dating. The mammalian fauna at Boxgrove has many similarities to the Cromerian (i.e. pre-Anglian) fauna, for there are a number of animals that are absent from post-Anglian sites such as Swanscombe: there are bears such as ursus denigeri and the rhinoceros stephanorhinus hunds¬ heimensis. The best indication of date comes from the 'vole clock'. Over 500,000 years ago, voles had molars with roots, but after that an evolutionary change took place as a result of which their molars ceased to have roots. The voles at Boxgrove have molars with vestigial roots.

The bone was in fact originally discovered in December 1993 by part-time amateur archaeologist Roger Pedersen. The site is a Middle Pleistocene land surface exposed at

The excavation, now in its 10th year and said to have cost English Heritage £750,000 so far, is directed by Mark Roberts (Institute of Archaeology, University College,

London), assisted by Simon Parfitt. Further excavations are now proposed when it is hoped more of the skeleton will be revealed.

Ice Age Weather It must be a shock for those who believe in very long and gradual changes in climate patterns to learn that at the end of the last Ice Age there were two abrupt changes back to glacial conditions, and that the changes were over a period of only 3- 5 years.

These conclusions follow from work on the Greenland ice core by R.B. Alley and colleagues at the Pennsylvania State University and other US institutions (Nature, 362, 1993, 527). Their method was to measure the annual ice layer thicknesses in the ice-core for a period of 15,000 years. The ice accumulation rate was found t o have doubled during the first shift back to glacial conditions and when there was a shift back from glacial to inter-glacial conditions again the temperature is estimated to have risen by 7° C.

What remains to be determined is the cause of this sudden shift in climate conditions. The favoured explanation i s that the Earth's climate system flips between several stable modes. They suggest that changes i n atmospheric carbon dioxide, and some other factors, could not have happened quickly enough to cause the observed effects. They conclude that in looking for causes one must consider whether there are fast acting components of the climate system such as sensitive trigger regions of deep oceanic convection and atmospheric circulation patterns.

Ancient Methane The Greenland Ice-core Project (GRIP) continues to provide research information bearing on ancient climates. A recent contribu­ tion arises from the work of J. Chappellaz et al who have measured

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