Oldest known jewellery discovered

Beads made from shells represent earliest personal adornment.

Nancy Hynes

It can take hundreds of beads to make a single bracelet, and thousands for a haute couture gown. But it has taken only three shell beads to shake up our theories about human evolution.

The jewellery might not be much by today's standards of bling: they are simple seashells punctured to make rudimentary beads. But archaeologists have dated two of them, from the site of Skhul in Israel, as at least 100,000 years old. This makes them the oldest known items of personal adornment, beating the previous record-holder, a set of similar shell beads found in South Africa's Blombos Cave, by almost 25,000 years.

The third bead, found at Oued Djebbana in Algeria, is younger at just over 35,000 years old, but what it lacks in age it makes up for in location. Found more than 160 kilometres from the sea, its presence clearly suggests intentional human transportation.

The two sites were excavated in the 1930s, but their significance has only recently come to light. "This study refutes the hypothesis that humans only became culturally modern when they entered Europe 40,000 years ago and replaced Neanderthals," says Marian Vanhaeren of University College London, UK, who led the research, published today in Science. Complex behaviour

The discovery is significant because it shows that our ancestors adopted symbolic behaviour much earlier than previously thought, says Vanhaeren. For decades, archaeologists had assumed that the complex behaviours such as language, burials and art first turned up about 40,000 years ago in Europe. So whereas modern humans may have physically evolved in Africa, their cultural development was thought to have largely occurred in Europe.

The Blombos Cave beads, found in 2004, were the first to shake that belief. And the new discoveries extend the geographic and temporal region in which early symbolic activity took place. Vanhaeren's team argues that a "long-lasting and widespread bead-working tradition" existed throughout Africa and the Middle East long before anatomically modern humans arrived in Europe.

This hypothesis does not contradict the appearance of European material 40,000 years ago, but instead challenges ideas about its role in human evolution, says Vanhaeren's colleague Chris Stringer, an anthropologist at the Natural History Museum in London. "What we find in Europe is very spectacular. The painted caves are very special, and we've found nothing like them yet in Africa or Asia," he says. "But we now know that the basic framework for that behaviour was already present around 100,000 years ago."

It is difficult to imagine any use for the pierced shells rather than as personal decoration, says Vanhaeren. But the use of jewellery suggests a complex social system. Beads and pendants may be used in gift-giving, as markers of ethnic, social or personal identity, or even as amulets. "When you put a personal ornament on your body, you are sending a message to other people," she says. "It is a silent language, but very powerful."

It is possible that other forms of symbolic material, such as wooden beads or bark paintings, may have existed before 100,000 years ago and simply not survived, Stringer suggests. "The Blombos find showed us how we can use beads as a window to social complexity. But it is only one window and there are many more to open."

Oldest known jewellery discovered

Warning against mobile phone use in storms

Lightning poses a threat to people who use mobile phones out of doors during a thunderstorm, say UK doctors.

Dr Swinda Esprit and two other senior London doctors report a case study in this week's British Medical Journal of a 15-year-old girl who was struck by lightning while using her mobile phone in a large city park during stormy weather.

The girl had an instant heart attack but was revived in time. She lost all memory of the incident, although the lightning strike was witnessed by other people.

A year later, though, the patient had become wheelchair-bound, suffering from physical, cognitive and emotional problems as well as a badly perforated eardrum in the left ear, the side where she had been holding the mobile phone.

The physicians, who work at Northwick Park Hospital in northwest London, say they have found three press reports of people being killed by lightning while using their mobile phones outdoors.

These incidents took place in China in 2005, in South Korea in 2004 and in Malaysia in 1999.

However, no similar cases have ever been reported in medical literature, they note.

"This rare phenomenon is a public health issue, and education is necessary to highlight the risk," say Esprit and colleagues.

As lightning chooses the easiest route to the ground, someone standing up and using the phone (and possibly wet at the same time) may well offer the path of least resistance.

Advice to the public from national safety authorities is either confused or nonexistent, the doctors say.

Australia's Lightning Protection Standard says that neither mobile phones nor cordless phones should used, or even carried, outdoors during a thunderstorm.

On the other hand, US National Weather Service says on its website that both are safe to use "because there is no direct path between you and the lightning".

Warning against mobile phone use in storms

Panda population far higher than expected

Scientists predicted that there were many more giant pandas than previously thought, following a novel study examining the DNA of their feces.

The experts, who used new "non-invasive" methods for counting wild animal numbers to re-examine panda population estimates, said the new method provided an accurate population profile.

The scientists published their results in the international journal Current Biology. The team was led by Professor Michael Bruford of the Cardiff School of Biosciences and Professor Fuwen Wei of the Institute of Zoology, the Chinese Academy of Sciences.

The giant panda is one of the world's most elusive and endangered species.

The traditional way to estimate panda populations is to examine the feces for the length of bamboo it contained, Bruford told Britain's domestic Press Association news agency.

Experts would then guess the panda's age and estimate how many different pandas the feces had come from.

"Without DNA profiling you are bound to under-estimate," Bruford said.

His team surveyed 10 square miles (26 square kilometres) of a Chinese reserve.

"We really combed the reserve. There were teams of people in a field walking in a line," the professor said.

It was previously thought that 27 giant pandas lived there. But Buford's team now reckons there are 66.

He predicted that the results would be replicated in other panda reserves.

"Our results found that previous surveys underestimated the population by more than 50 percent," said Bruford. "These findings indicate that the species has a much better chance of long-term viability, although we must not become complacent, since the population size is still perilously low." He warned: "We still may be only talking about a few thousand individuals. These guys are not common."

Giant pandas' traditional homes have been the mountains of central and southern China, as well as Myanmar and Vietnam.

But their numbers have fallen to only around 1,590, according to Chinese estimates, as their natural habitats have been destroyed by humans.

China founded its first nature reserve for giant pandas in the 1950s and now has 56 nature reserves for them, according to the Xinhua news agency.

It also has 183 giant pandas in captivity, while others have been sent to zoos around the world.

Panda population far higher than expected

Ancient web spins evolution story

The oldest-known spider web with prey still entrapped has been found preserved in a chunk of amber in Spain.

The mesh of silk strands snaring the remains of a fly, beetle, mite and wasp, dates back 110 million years to the time of the dinosaurs.

The fossil web appears to have been designed along the same lines as the round nets woven by modern spiders.

The find, described in Science, sheds light on the early evolution of spiders and the insects they fed on.

The web consists of some 26 silk strands preserved in a thin layer of amber together with arachnid prey.

Although it is not intact, enough of the web structure has survived to convince its discovers - from the University of Barcelona, Spain, and the American Museum of Natural History, New York, US - that it was probably a classical wheel-shaped, or orb, web. It is possibly the oldest spider web on record; an earlier single strand of spider silk preserved in Lebanese amber has been discovered although it is unclear if this was part of a true web.

"The advanced structure of this fossilised web (from Spain), along with the type of prey that the web caught, indicates that spiders have been fishing insects from the air for a very long time," said Dr David Grimaldi of the American Museum of Natural History.

"Spiders today have a huge impact as predators on insect populations, along with birds and bats."

Ancient web spins evolution story

Nature in the garden

Everyone can be a gardener. Perhaps you have a window box or a tub, or enjoy relaxing outside in the summer. Maybe you have an allotment or are involved in a local community gardening project. Whether you are an expert or simply enjoy growing plants in a pot there is a great deal you can do to encourage wildlife to visit.

There are more billions gardens in the world and these already provide a very important home for wildlife. But they could be far more valuable still if more people gardened with wildlife in mind.

Here are some top tips for nature-friendly gardening.

	Try and introduce natural predator control. Beneficial insects and other small invertebrates can be your best friends when it comes to controlling pests in your garden and vegetable patch. Planting annuals such as Californian poppies and marigolds among your vegetables will attract a wealth of beneficial insects, like ladybirds and hoverflies, which will eat aphids.

	Try to avoid the use of chemicals, such as pesticides and fertilisers. Almost all chemicals will kill plants and animals beyond those targeted. Work with nature rather than against it.

	Make your own compost and ask for peat-free products when buying from your local garden centre. Peat extraction is damaging a fragile wild habitat that cannot be recreated so avoid using peat in the garden. Instead, make your own compost from kitchen and garden waste.
	Create a pond. Water bodies - even very small ones - are wonderful for wildlife. If you are short of space try placing a container, such as an old enamel or china sink, in your garden. Remember to add a few stones at one end, so that frogs and toads can get out easily.
	Plant some native shrubs or trees. Flowering and fruiting trees and shrubs provide a source of food and shelter for small mammals and birds.
	Choose plants that offer nectar and pollen. Go for old cottage garden plants, and avoid those with complex flowers. Generally speaking, the more complex or highly bred the flower, the less it will have to offer bees, butterflies and other insects. Native plants will often be better for insects but many exotic plants are good too.
	Don't just feed the birds! You can make your garden more attractive to birds by providing them with a wide range of food. The greater the choice of food you offer, the more species you are likely to see. If you have a cat, put a bell on its collar to alert birds.
	Leave a small pile of logs in the corner of your garden. Decaying logs in a quiet shady corner will provide a home for a wide range of insects and mammals, such as hedgehogs. Ideally, some of the logs should be upright and partially buried in the earth.
	Use a water butt to collect rainwater from house, shed and garage roofs. Using this in the garden will reduce the consumption of mains water. Huge amounts of energy are wasted on cleaning and transporting mains water and it is often extracted from rivers at levels that threaten local wildlife.
	Use the right rocks! What kind of stone can you use in your garden without causing damage to rare landscapes? Avoid using water-worn limestone and tufa as they are a non-renewable resource and may come from protected sites. Check where your pebbles come from and avoid those removed from beaches. On a large scale, such removal can cause damage to rare habitats.
	Check the origin of any wood you buy for the garden. If you're not careful, you may be unknowingly contributing to the destruction of tropical rain forests. Wood products (including paper) with the Forest Stewardship Council (FSC) label are from well-managed forests. FSC is an international, non-governmental body.

Nature in the garden