Archaeology: Ancient bones could help combat TB

Archaeologists and medical researchers are joining forces to examine human remains from Jericho in a real-life version of 'Bonekickers'

Robin McKie in London and Toni O'Loughlin in Jerusalem

Ancient bones from the city of Jericho are to be used by British scientists to develop treatments for tuberculosis. The project is part of a new scientific discipline in which archaeologists and medical researchers are cooperating to gain insights into modern ailments.

Other diseases being tackled this way include syphilis, malaria, arthritis and influenza. Ancient history holds vital clues in seeking out treatments for modern diseases, according to these real-life counterparts of TV's new archaeological detective series Bonekickers, starring Hugh Bonneville and Adrian Lester. The programme gives dramatic relevance to the study of archaeology, as UK scientists are doing with the study of ancient diseases.

This point is stressed by project leader Professor Mark Spigelman, of University College London. 'I don't think we've got new diseases today; we have got variations of old diseases,' he told The Observer.

The team, which also includes Israeli, Palestinian and German researchers, will be following up pioneering work by British archaeologist Kathleen Kenyon. In the Fifties she made a series of important digs at Jericho and found bones from thousands of humans, some dating back 8,000 years.

When these bones were examined, it was discovered many had lesions, indicating that the city's men and women had suffered from tuberculosis. The walls of Jericho may have come down, not with a trumpet blast, but with epidemic of coughing, it seems.

Now Spigelman and his team have begun studying DNA from these remains in order to identify genes that might have helped to make the people of Jericho susceptible or resistant to tuberculosis, and so help in the development of more effective treatments for the disease.

In addition, the team will study how the TB bacterium evolved over the millennia. 'As humans grew up, the bugs grew up - and we are looking for these changes,' said Spigelman.

Crucially, TB needs an urban environment to survive. 'TB is a disease of crowds because it spreads by people coughing,' added Spigelman. And given that Jericho was one of the world's oldest cities, its human remains are crucial to investigating the roots of TB thousands of years ago.

'Jericho is pivotal because it gives us a founder population from a very, very early site of urbanisation,' he added.

Today TB infects nine million people a year - 450,000 with a strain that is resistant to first-line drugs, according to the World Health Organisation. The need to gain new insights into the disease has therefore become urgent.

Not every disease is susceptible to such research, however. According to Dr Simon Mays at English Heritage's Ancient Monuments Laboratory, many illnesses leave no marks on the skeletons of their victims, making it impossible for scientists to pinpoint the bones of disease victims and to study them.

'For example, viral infections tend to be rapid in their impact and leave no trace,' he said. 'On the other hand, many bacterial infections do leave bone lesions, however - such as TB, leprosy and syphilis. Each of these has become of the focus of research, as a result.

'Historical clues are also useful. We can study the skeletons of bubonic plague victims because we know many were buried in special communal graves.'

In addition, scientists recently exhumed the bodies of victims of the 1918 flu epidemic because they had been buried in marked graves. Data from this research has been crucial in preparing medical defences against future epidemics, added Mays.

In addition, digs in Britain have provided evidence of arthritis spread through the population during the Middle Ages.

'Archaeological research has also shown that until relatively recently, children were weaned around the age of three,' said archaeologist David Miles, 'for the reason that late-weaned children were better protected against infections. Weaning children early, as we do today, is not necessarily a good thing, the lesson of history would suggest.'

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Will Our Future Brains Be Smaller?

Will our future brains be smaller? It has been thought for some years that mammals have two decision-making systems in their brains which operate at different speeds to cope with different situations. Do we still benefit from using both? (Credit: iStockphoto/Vasiliy Yakobchuk)

The speed at which we react to threatening situations can have life or death implications. In the more primitive past, it could have meant escaping a wild animal; today it might mean swerving to avoid a head-on car crash.

It has been thought for some years that mammals have two decision-making systems in their brains which operate at different speeds to cope with different situations. New research from the University of Bristol supports this theory and has shown that the evolutionary pressures arising from the older, faster, but less accurate, part of the brain may have shaped the more recent development of the slower-acting but more precise cortex, found in humans and higher animals.

Pete Trimmer, lead author on the study, explained: "If we compare the brain of a human with that of a reptile, we find they are very similar except that mammals have a large 'outer cortex' around the outside of the existing 'sub-cortical' brain, that is common to other vertebrates.

"The fact that lizards make decisions indicates that the sub-cortical brain in humans is also likely to be used in decision-making. However, fMRI scans now reveal that parts of the outer cortex (which developed more recently in our evolutionary past) are also used when making decisions."

Why does the brain need these two decision-making areas? What benefit does the new cortex bring? After all, extra brain means extra weight and energy required to carry it around. Furthermore, is the older sub-cortical system now largely redundant? If so, could we expect it to atrophy in future humans so our brains become smaller?

To address these questions, Trimmer built theoretical models representing the two systems in which the sub-cortical system was assumed to act very quickly but inaccurately, whereas the cortex allowed information to be gathered before making an informed decision, and was therefore slower.

The results of their modelling showed that when the threat level is high, such as the risk of being attacked by a dangerous animal, it is very useful to have the fast-acting, if inaccurate, system. But when dealing with situations which don't occur very often, or complex scenarios with many conflicting cues such as social situations, the cortical system is of more use than the sub-cortical system.

Trimmer commented: "As life became more complex, the benefit of gathering information before making a decision put an evolutionary pressure on the early brain. This may have led to the rapid development of the cortex in mammals. So if humans continue to live in a world of dangers such as wild animals or fast-moving cars, there will still be an evolutionary benefit to maintaining the sub-cortical system, and it is unlikely to atrophy in future humans."

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Secret chamber may solve Mexican pyramid mystery

By Tom Leonard in New York

AP

The Aztecs believed the city was divine and identified it with the place where the sun was created

AFP/GETTY

The tunnel entrance was discovered by accident in 1971 while workmen were installing a sound and light show

EPA

After initial tests, it was dismissed as a natural cave and sealed two years later

GETTY

Hundreds of Mexicans stiil gather at the Pyramid of the Sun to receive energy from the sun during spring equinox

With its soaring stone pyramids and geometric temples, Teotihuacan was once the biggest city in the Americas and possibly the world.

However, experts have never been able to say with certainty who built it and why it was suddenly abandoned.

An international team of experts believes the answer may lie under the Pyramid of the Sun, the centre point of the vast ruined city 25 miles outside Mexico City.

At the end of this month, they are to investigate a man-made tunnel and cave system underneath the pyramid – the third biggest in the world – to test theories that it was used for rituals including human sacrifice.

"We think it had a ritual purpose. Offerings were placed at the very end of the tunnel as part of the pyramid's construction process," said Alejandro Sarabia, Teotihuacan's director of archaeology.

He will lead a team of Mexican, American and Japanese experts into a 295 ft long, 8 ft high tunnel some 20 ft below the pyramid.

"We want to find out why the Teotihuacan people sealed it and when," Mr Sarabia said. "Excavating the cave could give us some clues about what happened at Teotihuacan, about the fate of the city."

At its zenith between 150 AD and 450 AD, Teotihuacan was home to up to 200,000 people of various ethnic origins and thought to have been larger than any European city at the time, including Rome.

But, sometime in the 7th or 8th century, it was set ablaze – possibly as the result of an insurrection – and abandoned.

The Aztecs believed the city was divine and identified it with the place where the sun was created. They also gave it its name, which roughly translates as ''The place where men became gods.''

The tunnel entrance was discovered by accident in 1971 while workmen were installing a sound and light show for the 738 ft wide pyramid.

After initial tests, it was dismissed as a natural cave and sealed two years later. Much of the information about it was lost when the archaeologist who found it died.

Mr Sarabia said: "If we can find out what happened, when, and perhaps how, it will give us a better idea about the history of the Pyramid of the Sun and of the city in general."

He said it was unlikely that the cave would have been used for everyday events and would probably have been accessible to only a select few.

"It may well have been used for sacrificial rites, dancing or other rituals," Mr Sarabia said.

The sacrifices are likely to have been human ones, he added.

Evidence of human sacrifice has been found all around the city, including the remains of children buried at each corner of the Pyramid of the Sun.

It is believed these burials were part of a ritual dedication of the building while other victims, probably captured enemy warriors, were killed to bring the city good luck.

Mr Sarabia said the excavation work would be "tricky" because there was virtually no light and the entrance to the tunnel was in poor condition.

For many years, archaeologists believed the city was built by the Toltecs but it is now accepted that their civilisation came centuries later.

Teothiuacan, which has World Heritage Site status, is still visited by thousands each year to celebrate the spring equinox.

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