Tuesday, 27 March 2012

Laser tag

Since the Leonardo diCaprio film, and to a lesser extent Naomi Campbell's bizarre turn as a star witness in the Charles Taylor trial, many people have now heard of blood diamonds. Put simply, they are diamonds from war-torn regions which are used to finance military groups and perpetuate the violence. Often they are collected using what's essentially slave labour in concentration camp conditions. They're a bad thing. It's not just diamonds, though. Other gemstones and mineral resources are similarly exploited for nefarious ends.

The diamond trade has attempted to address the issue as best it can, tracing origins of stones where possible. Prohibiting sources of dubious nature and implementing national embargoes where necessary. It's worked, to some extent, but any help is welcome. The high-profile link to such misery does nothing to help business, after all. So - the developing ability to determine a stone's source locality is good news. In National Geographic this month is an article on a Texan company, Materialytics, who fire a laser at a stone and read the spectrum of light produced to get a locality-specific result. They can be 95% certain of where a diamond came from, for example - the mine, not just the country. They're still in the process of building their database, but this has the potential to be an effective weapon in the war on... well... war? Sort of.

Wednesday, 7 March 2012

Wood filler

Stan Wood has made his name in the world of palaeontology by finding fossils where people think he won't. Going back to sites thought long-exhausted, doggedly hunting for the 'right' rocks in places where others may have given up. Wading out to waist-deep water before beginning to dig. For twenty years, Stan was convinced there were fossils in the Scottish Borders that could help plug Romer's Gap. Eventually, in 2008, he began to find them. Not much of a surprise for those that know him, the stubborn old goat.

 The material Stan has dug out of a few Borders site in the past few years shows a range that suggests a relatively healthy biodiversity existed at a time when it had been thought atmospheric oxygen levels and the after-effects of the Devonian extinctions had left (at least marine) life reeling a little. The tetrapods at the end of the Devonian were not terrestrial in general, but by the end of the Gap, 345 million years ago, they had made a successful colonisation of land. The positioning of Romer's Gap in the fossil record meant their invasion of terra firma has been hidden from us.

Rather than accepting the idea that there simply wasn't much to find, Stan went out and found something. The exhibit, on at the National Museum of Scotland on Chambers Street in Edinburgh until the 29th of April, shows a millipede, plants, fish, a eurypterid and some amphibian bones. The star, however, has got to be Ribbo. Yet to receive its full scientific name, the nickname is due to its sturdy ribs. It's in a bit of a mess, disarticulated and a little scattered, but Mike Coates' reconstruction, right, shows how the animal may have looked in life. Probably a little less yellow.

The material isn't the most aesthetic, but its contribution to science is enormous and it will be heavily studied to squeeze as much information from the 350 million year-old limestone as possible. The University Museum of Zoology in Cambridge has more material from the sites, but I'm glad Ribbo has been housed in the same museum as Lizzie. Seems right, somehow.

Monday, 5 March 2012

Mind the gap

The start of the Carboniferous, about 360 million years ago, was an important evolutionary period. In the oceans, there were some bizarre sharks, including the shop's logo, Akmonistion. Huge rhizodonts swam the rivers and eurypterids were in their prime. On land, though, things seem to be relatively quiet.

Amphibians were established but reptiles had yet to show up, and it's the development of the tetrapods that's so important. There isn't much fossil material thrown up by this period. In fact, there's so little that the first fifteen million years of the Carboniferous, from 360mya to 345mya, have a name - Romer's Gap. Alfred Romer, an American palaeontologist, first described this puzzling gap in the fossil record, wondering if there was particular reason or set of circumstances behind the missing information. Geochemical analysis of the rocks of that time suggest the lack of fossils may be the result of a period of low atmospheric oxygen, which would not promote the development of terrestrial animals, but the hangover of an extinction event usually needs more than a couple of aspirin to shake off, too.

Stan Wood has already contributed hugely significant finds from the East Kirkton quarry to help fill the gap, in Westlothiana and others, but tomorrow sees the opening of an exhibition of his recent finds which may shed some more light on the gap. The material will go on public display tomorrow at the National Museum on Chambers Street and the associated scientific paper will be published in the Proceedings of the National Academy of Sciences. Stan looks to have come up with the goods once again.