Found: Darwin’s long-lost fossil collection

A “treasure trove” of fossils collected by the greatest biologists of the early 19th century, including Charles Darwin and Joseph Hooker, has been rediscovered after being lost for more than 150 years.

Howard Falcon-Lang, a palaeontologist at Royal Holloway, University of London, found the collection – 314 glass slides containing thin, polished slices of fossilised plants – in an old cabinet at the headquarters of the British Geological Survey near Nottingham.

While looking for specimens for a research project, he noticed some drawers marked “unregistered fossil plants” and pulled one open to take a look. “What I found made my jaw drop,” he says. “Inside the drawer were hundreds of beautiful glass slides made by polishing fossil plants into thin translucent sheets.

“Almost the first slide I picked up was labelled ‘C. Darwin Esq.’ This turned out to be a piece of fossil wood collected by Darwin during his famous voyage on the Beagle in 1834.”

Further investigation showed that the famous botanical explorer Joseph Hooker, who was Darwin’s best friend, assembled the collection while working for the British Geological Survey in 1846. It also includes fossils that Hooker himself found during an intrepid voyage in the southern oceans in 1840; others came from John Henslow, Darwin’s mentor at Cambridge.

Another important part of the collection was created by William Nicol, an Edinburgh geologist who, in the 1820s, invented the process of mounting a fossil on a glass plate and then grinding it down to a translucent slice just 0.05mm thick, for study under a microscope. His technique was quickly adopted by Darwin, Hooker and Henslow.

The collection was lost because Hooker failed to number the specimens in the formal register before setting out on an expedition to the Himalayas in the late 1840s. The “unregistered” fossils were moved to the Museum of Practical Geology in Piccadilly in 1851 and then transferred to the Geological Museum in South Kensington in 1935 and finally on to the British Geological Survey HQ in 1985.

By then their significant past was long forgotten.

Some of the specimens are far larger than today’s microscope slides, measuring up to 15cm by 10cm, and very beautiful.

Besides the collection’s aesthetic and historical significance – it accounts for about one-third of the fossil specimens left by Darwin and his circle – it remains scientifically important. “We might get a dozen [scientific] papers by examining the specimens in the Hooker collection,” says Falcon-Lang.

The British Geological Survey has set up an online museum to showcase the Hooker collection.

From sunflower to solar power

Solar power is the latest field of technology to take inspiration from Mother Nature.

Researchers at Massachusetts Institute of Technology and RWTH Aachen University in Germany have come up with an improved design for the giant mirrors that focus the sun’s heat in the new generation of “concentrating solar power” plants.

Appropriately, their inspiration is the sunflower.

Taking as an example the PS10 plant in Spain’s Andalusian desert, the researchers found that the amount of land required by its 600 concentrating mirrors would be cut by almost 20 per cent, if they were arranged in a spiral like the florets on the disk of a sunflower. At the same time its overall efficiency would increase.

The sunflower’s florets (which eventually become its seeds) follow a pattern known as a Fermat spiral, which appears in many natural objects. Each floret is turned at the “golden angle” of 137° to its neighbour.

This arrangement is more efficient than the one used at PS10, in which the mirrors are installed around the central generating tower in concentric circles, each offset from the one in front – a bit like some theatres where the seats are offset to reduce the chance that your view will be blocked by a head in the row in front.

If PS10 had been built in a Fermat spiral, the mirrors would shade one another less than is actually the case. The research appears in the journal Solar Energy.

It would not be cost-effective to rebuild PS10 in this way but MIT engineering professor Alexander Mitsos hopes the research will guide future designs. “Concentrated solar thermal energy needs huge areas,” he says, “so we’d better use them efficiently.”

Seeing eye to eye on facial recognition

The availability of accurate eye tracking instruments is enabling scientists to investigate better how people acquire and process visual information – and particularly how they recognise faces.

Psychologists have long known that we are better at distinguishing faces and recognising people from the same race as ourselves (or, strictly speaking, from the group that dominated our childhood experiences). But new research is showing that different races tend to follow different facial cognition strategies.

Researchers at Glasgow University found that westerners tend to follow a “triangular” looking pattern, moving between the two eyes and mouth, while people who have grown up in China focus more on the centre of the face around the nose.

The latest study – undertaken at the University of Nottingham’s Malaysia campus in Selangor and published in the journal PLoS One – shows that Malaysian Chinese follow a strategy that seems to be different from both westerners and mainland Chinese but combines features of both.

They focus on the eyes and nose but less on the mouth.

“We think that people learn how to recognise faces from the faces that they encounter,” said Ian Stephen, a facial recognition expert at Nottingham. “Although Malaysia is an east Asian country its ethnic composition is highly diverse. The intermediate looking strategy that Malaysian Chinese use allows them to recognise western faces just as well as Asians.”

Can our genes help us stay smart?

Although there have been many studies of the genetic contribution to intelligence, researchers in Scotland and Australia have just carried out what they say is the first assessment of the way genes determine changes in intelligence across the human lifespan.

The results, published in Nature, show that genetic factors account for just 24 per cent of change in intelligence between childhood and old age. That suggests “how important the environment is in helping us to stay sharp as we age,” says Peter Visscher of the University of Queensland, who carried out the study with colleagues at Edinburgh and Aberdeen universities.

The study was made possible by Scotland’s rich heritage of cognitive test data. In 1932 and 1947 intelligence tests were carried out on almost all Scottish children born in 1921 and 1936 respectively.

For the latest research, 2,000 of these subjects were traced and re-tested in old age. The new results were compared with their scores at the age of 11 – and with DNA analysis of their genome.

“These results partly explain why some people’s brains age better than others,” says Ian Deary of Edinburgh University.

The sample was not large enough to identify specific genetic or environmental factors that made some people’s intelligence last better than others, although these may emerge from future research. “Our results provide the warrant for others and ourselves to search for them,” adds Visscher.


For crying out loud

The sound of babies crying produces a better performance in the arcade game “Whack-a-mole” than birdsong or adult cries. Scientists believe this is due to an innate physiological response.

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