̽��ֱ�� of Cambridge - bone

Prehistoric women’s manual work was tougher than rowing in today’s elite boat crews

fpjl2 — Wed, 29 Nov 2017 19:01:03 +0000

A new study comparing the bones of Central European women that lived during the first 6,000 years of farming with those of modern athletes has shown that the average prehistoric agricultural woman had stronger upper arms than living female rowing champions.

Researchers from the ̽��ֱ�� of Cambridge’s Department of Archaeology say this physical prowess was likely obtained through tilling soil and harvesting crops by hand, as well as the grinding of grain for as much as five hours a day to make flour.

Until now, bioarchaeological investigations of past behaviour have interpreted women’s bones solely through direct comparison to those of men. However, male bones respond to strain in a more visibly dramatic way than female bones.

̽��ֱ��Cambridge scientists say this has resulted in the systematic underestimation of the nature and scale of the physical demands borne by women in prehistory.

“This is the first study to actually compare prehistoric female bones to those of living women,” said Dr Alison Macintosh, lead author of the study published today in the journal Science Advances.

“By interpreting women’s bones in a female-specific context we can start to see how intensive, variable and laborious their behaviours were, hinting at a hidden history of women’s work over thousands of years.”

̽��ֱ��study, part of the European Research Council-funded ADaPt (Adaption, Dispersals and Phenotype) Project, used a small CT scanner in Cambridge’s PAVE laboratory to analyse the arm (humerus) and leg (tibia) bones of living women who engage in a range of physical activity: from runners, rowers and footballers to those with more sedentary lifestyles.

̽��ֱ��bones strengths of modern women were compared to those of women from early Neolithic agricultural eras through to farming communities of the Middle Ages.

“It can be easy to forget that bone is a living tissue, one that responds to the rigours we put our bodies through. Physical impact and muscle activity both put strain on bone, called loading. ̽��ֱ��bone reacts by changing in shape, curvature, thickness and density over time to accommodate repeated strain,” said Macintosh.

“By analysing the bone characteristics of living people whose regular physical exertion is known, and comparing them to the characteristics of ancient bones, we can start to interpret the kinds of labour our ancestors were performing in prehistory.”

Over three weeks during trial season, Macintosh scanned the limb bones of the Open- and Lightweight squads of the Cambridge ̽��ֱ�� Women’s Boat Club, who ended up winning this year’s Boat Race and breaking the course record. These women, most in their early twenties, were training twice a day and rowing an average of 120km a week at the time.

̽��ֱ��Neolithic women analysed in the study (from 7400-7000 years ago) had similar leg bone strength to modern rowers, but their arm bones were 11-16% stronger for their size than the rowers, and almost 30% stronger than typical Cambridge students.

̽��ֱ��loading of the upper limbs was even more dominant in the study’s Bronze Age women (from 4300-3500 years ago), who had 9-13% stronger arm bones than the rowers but 12% weaker leg bones.

A possible explanation for this fierce arm strength is the grinding of grain. “We can’t say specifically what behaviours were causing the bone loading we found. However, a major activity in early agriculture was converting grain into flour, and this was likely performed by women,” said Macintosh.

“For millennia, grain would have been ground by hand between two large stones called a saddle quern. In the few remaining societies that still use saddle querns, women grind grain for up to five hours a day.

“ ̽��ֱ��repetitive arm action of grinding these stones together for hours may have loaded women's arm bones in a similar way to the laborious back-and-forth motion of rowing.”

However, Macintosh suspects that women’s labour was hardly likely to have been limited to this one behaviour.

“Prior to the invention of the plough, subsistence farming involved manually planting, tilling and harvesting all crops,” said Macintosh. “Women were also likely to have been fetching food and water for domestic livestock, processing milk and meat, and converting hides and wool into textiles.

“ ̽��ֱ��variation in bone loading found in prehistoric women suggests that a wide range of behaviours were occurring during early agriculture. In fact, we believe it may be the wide variety of women’s work that in part makes it so difficult to identify signatures of any one specific behaviour from their bones.”

Dr Jay Stock, senior study author and head of the ADaPt Project, added: “Our findings suggest that for thousands of years, the rigorous manual labour of women was a crucial driver of early farming economies. ̽��ֱ��research demonstrates what we can learn about the human past through better understanding of human variation today.”

̽��ֱ��first study to compare ancient and living female bones shows that women from early agricultural eras had stronger arms than the rowers of Cambridge ̽��ֱ��’s famously competitive boat club. Researchers say the findings suggest a “hidden history” of gruelling manual labour performed by women that stretched across millennia.

By interpreting women’s bones in a female-specific context we can start to see how intensive, variable and laborious their behaviours were

Alison Macintosh

Prehistoric women’s manual work was tougher than rowing in today’s elite boat crews

Alastair Fyfe for the ̽��ֱ�� of Cambridge

Cambridge ̽��ֱ�� Women’s Boat Club Openweight crew rowing during the 2017 Boat Race on the river Thames in London. ̽��ֱ��Cambridge women’s crew beat Oxford in the race. ̽��ֱ��members of this crew were among those analysed in the study.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Would you live in a city made of bone?

sc604 — Thu, 23 Jun 2016 13:47:51 +0000

Between them, concrete and steel are responsible for as much as a tenth of worldwide carbon emissions. Before they ever reach a construction site, both steel and concrete must be processed at very high temperatures – which takes a lot of energy. And yet, our cities are completely dependent on these two unsustainable materials.

“I fly back and forth a lot between the UK and the US, and I’d been harbouring a lot of guilt about the effect that had on my carbon footprint – I’d always assumed, as many of us do, that air travel is a huge contributor to carbon emissions,” says bioengineer Dr Michelle Oyen of Cambridge’s Department of Engineering. “But the truth is, while the emissions caused by air travel are significant, far more are caused by the production of concrete and steel, which of course is what most cities are built from.”

So what does that mean for cities of the future, as more and more of us live in urban areas? How can we continue to build while reducing carbon emissions?

Whereas some researchers are investigating ways of producing steel and concrete in more energy-efficient ways, or finding ways of using less, Oyen would rather turn the tables completely, and create new building materials that are strong, sustainable and take their inspiration from nature.

“What we’re trying to do is to rethink the way that we make things,” says Oyen. “Engineers tend to throw energy at problems, whereas nature throws information at problems – they fundamentally do things differently.”

Oyen works in the field of biomimetics – literally ‘copying life’. In her lab, with funding support from the US Army Corps of Engineers, she constructs small samples of artificial bone and eggshell, which could be used as medical implants, or even be scaled up and used as low-carbon building materials.

Like the real things, artificial bone and eggshell are composites of proteins and minerals. In bone, the proportions of protein and mineral are roughly equal – the mineral gives bone stiffness and hardness, while the protein gives it toughness or resistance to fracture. While bones can break, it is relatively rare, and they have the benefit of being self-healing – another feature that engineers are trying to bring to biomimetic materials.

In eggshell, the ratios are different: about 95% mineral to 5% protein, but even this small amount of protein makes eggshell remarkably tough considering how thin it is.

When making the artificial bone and eggshell, the mineral components are ‘templated’ directly onto collagen, which is the most abundant protein in the animal world. “One of the interesting things is that the minerals that make up bone deposit along the collagen, and eggshell deposits outwards from the collagen, perpendicular to it,” says Oyen. “So it might even be the case that these two composites could be combined to make a lattice-type structure, which would be even stronger – there’s some interesting science there that we’d like to look into.”

In her lab, Oyen and her team have been making samples of artificial eggshell and bone via a process that could be easily scaled up – and since the process takes place at room temperature, the samples take very little energy to produce. But it may be some time before we’re living in bone and eggshell houses.

For one, the collagen that Oyen needs to make these materials comes from natural (meaning animal) sources. One of the things she’s currently investigating is whether a non-animal-derived or even synthetic protein or polymer could be used instead of natural collagen.

“Another issue is the construction industry is a very conservative one,” Oyen says. “All of our existing building standards have been designed with concrete and steel in mind. Constructing buildings out of entirely new materials would mean completely rethinking the whole industry. But if you want to do something really transformative to bring down carbon emissions, then I think that’s what we have to do. If we’re going to make a real change, a major rethink is what has to happen.”

Dr Michael Ramage from the Department of Architecture is another Cambridge researcher who believes we need to expand our use of natural materials in buildings. Ramage has several ongoing research projects that are looking into the use of wood – one of the oldest building materials we have – for tall buildings.

Working with PLP Architecture and engineers Smith and Wallwork, Ramage recently delivered plans for an 80-storey, 300 m high, timber skyscraper to the Mayor of London. ̽��ֱ��proposals currently being developed would create more than 1,000 residential units in a 1 million square-foot, mixed-use tower and mid-rise terraces, integrated into the Barbican in central London.

Like other natural materials, the primary benefit of using wood as a building material is that it is a renewable resource, unlike concrete and steel. Ramage’s research is also investigating other potential benefits of using wood for tall buildings, such as reduced costs and improved construction timescales, increased fire resistance and a significant reduction in the overall weight of buildings.

“If London is going to survive an increasing population, it needs to densify,” says Ramage. “One way is taller buildings. We believe people have a greater affinity for taller buildings in natural materials rather than steel and concrete towers. ̽��ֱ��fundamental premise is that timber and other natural materials are vastly underused and we don’t give them nearly enough credit. Nearly every historic building, from King’s College Chapel to Westminster Hall, has made extensive use of timber.”

̽��ֱ��tallest timber building in the world at the moment is a 14-storey apartment block in Bergen, Norway, but Ramage foresees future cities where timber skyscrapers sit alongside those made of concrete and steel.

“Future cities may not look a whole lot different – you may not know immediately if you are in a timber, steel or concrete building,” says Ramage. “But cities might be a whole lot quieter, as most timber buildings are built off site, and then just assembled on site, and use roughly a fifth as much truck traffic as equivalent concrete buildings. In other words, what needs to be delivered in five trucks for a concrete building can be delivered in one truck for a timber building. That’s an incredible advantage, for cost, for environment, for traffic and for cyclists.”

“ ̽��ֱ��material properties of bone and wood are very similar,” says Oyen. “Just because we can make all of our buildings out of concrete and steel doesn’t mean we should. But it will require big change.”

̽��ֱ��cities of today are built with concrete and steel – but some Cambridge researchers think that the cities of the future need to go back to nature if they are to support an ever-expanding population, while keeping carbon emissions under control.

Just because we can make all of our buildings out of concrete and steel doesn’t mean we should. But it will require big change

Michelle Oyen

Abdul Rahman

City

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Hunter-gatherer past shows our fragile bones result from physical inactivity since invention of farming

fpjl2 — Mon, 22 Dec 2014 20:02:37 +0000

New research across thousands of years of human evolution shows that our skeletons have become much lighter and more fragile since the invention of agriculture - a result of our increasingly sedentary lifestyles as we shifted from foraging to farming.

̽��ֱ��new study, published today in the journal PNAS, shows that, while human hunter-gatherers from around 7,000 years ago had bones comparable in strength to modern orangutans, farmers from the same area over 6,000 years later had significantly lighter and weaker bones that would have been more susceptible to breaking.

Bone mass was around 20% higher in the foragers - the equivalent to what an average person would lose after three months of weightlessness in space.

After ruling out diet differences and changes in body size as possible causes, researchers have concluded that reductions in physical activity are the root cause of degradation in human bone strength across millennia. It is a trend that is reaching dangerous levels, they say, as people do less with their bodies today than ever before.

Researchers believe the findings support the idea that exercise rather than diet is the key to preventing heightened fracture risk and conditions such as osteoporosis in later life: more exercise in early life results in a higher peak of bone strength around the age of 30, meaning the inevitable weakening of bones with age is less detrimental.

There is, in fact, no anatomical reason why a person born today could not achieve the bone strength of an orangutan or early human forager, say researchers; but even the most physically active people alive are unlikely to be loading bones with enough frequent and intense stress to allow for the increased bone strength seen in the ‘peak point’ of traditional hunter-gatherers and non-human primate bones.

“Contemporary humans live in a cultural and technological milieu incompatible with our evolutionary adaptations. There’s seven million years of hominid evolution geared towards action and physical activity for survival, but it’s only in the last say 50 to 100 years that we’ve been so sedentary - dangerously so,” said co-author Dr Colin Shaw from the ̽��ֱ�� of Cambridge’s Phenotypic Adaptability, Variation and Evolution (PAVE) Research Group.

“Sitting in a car or in front of a desk is not what we have evolved to do.”

̽��ֱ��researchers x-rayed samples of human femur bones from the archaeological record, along with femora from other primate species, focusing on the inside of the femoral head: the ball at the top of the femur which fits into the pelvis to form the hip joint, one of the most load-bearing bone connections in the body.

Two types of tissue form bone: the cortical or ‘hard’ bone shell coating the outside, and the trabecular or ‘spongy’ bone: the honeycomb-like mesh encased within cortical shell that allows flexibility but is also vulnerable to fracture.

̽��ֱ��researchers analysed the trabecular bone from the femoral head of four distinct archaeological human populations representing mobile hunter-gatherers and sedentary agriculturalists, all found in the same area of the US state of Illinois (and likely to be genetically similar as a consequence).

̽��ֱ��trabecular structure is very similar in all populations, with one notable exception: within the mesh, hunter-gatherers have a much higher amount of actual bone relative to air.

“Trabecular bone has much greater plasticity than other bone, changing shape and direction depending on the loads imposed on it; it can change structure from being pin or rod-like to much thicker, almost plate-like. In the hunter-gatherer bones, everything was thickened,” said Shaw.

This thickening is the result of constant loading on the bone from physical activity as hunter-gatherers roamed the landscape seeking sustenance. This fierce exertion would result in minor damage that caused the bone mesh to grow back ever stronger and thicker throughout life - building to a ‘peak point’ of bone strength which counter-balanced the deterioration of bones with age.

Shaw believes there are valuable lessons to be learnt from the skeletons of our prehistoric predecessors. “You can absolutely morph even your bones so that they deal with stress and strain more effectively. Hip fractures, for example, don’t have to happen simply because you get older if you build your bone strength up earlier in life, so that as you age it never drops below that level where fractures can easily occur.”

Other theories for humans evolving a lighter, more fragile skeleton include changes in diet or selection for a more efficient, lighter skeleton, which was never reversed.

While the initial switch to farming did cause a dip in human health due to monoculture diets that lacked variety, the populations tested were unaffected by this window in history. “Of course we need a level of calcium to maintain bone heath, but beyond that level excess calcium isn’t necessary,” said Shaw.

̽��ֱ��research also counters the theory that, at some point in human evolution, our bones just became lighter - perhaps because there wasn’t enough food to support a denser skeleton. “If that was true, human skeletons would be entirely distinct from other living primates. We’ve shown that hunter-gatherers fall right in line with primates of a similar body size. Modern human skeletons are not systemically fragile; we are not constrained by our anatomy.”

“ ̽��ֱ��fact is, we’re human, we can be as strong as an orangutan - we’re just not, because we are not challenging our bones with enough loading, predisposing us to have weaker bones so that, as we age, situations arise where bones are breaking when, previously, they would not have” Shaw said.

While the 7,000-year-old foragers had vastly stronger bones than the 700-year-old farmers, Shaw says that neither competes with even earlier hominids from around 150,000 years ago. “Something is going on in the distant past to create bone strength that outguns anything in the last 10,000 years.”

̽��ֱ��next step for Shaw and colleagues will be to provide insight into the kind of mobility that gave our ancient ancestors such powerful physical strength.

Inset GIF: CT scan of the femoral head of a hunter-gatherer hip bone

Latest analysis of prehistoric bones show there is no anatomical reason why a person born today could not develop the skeletal strength of a prehistoric forager or a modern orangutan. Findings support the idea that activity throughout life is the key to building bone strength and preventing osteoporosis risk in later years, say researchers.

Sitting in a car or in front of a desk is not what we have evolved to do

Colin Shaw

Forager past shows our fragile bones result from physical inactivity since invention of farming

Colin Shaw and Timothy Ryan

Hunter-gatherer bone mass (left) compared with agriculturalist bone mass (right)

̽��ֱ��text in this work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page. For image rights, please see the credits associated with each individual image.

Yes

Body builders: collagen scaffolds

lw355 — Wed, 04 Jun 2014 09:07:30 +0000

It may not look like much to the naked eye, but collagen is remarkably strong. ̽��ֱ��most abundant protein in the animal kingdom, it gives strength and structure to skin, tendons, ligaments, smooth muscle tissue and many other parts of the body.

Through precise manipulation at a structural level, collagen can also be used as a construction material in the laboratory or clinic to help regenerate new tissue, repair damaged cartilage and bone, or aid in the development of new therapies for cardiac disease, blood disorders and cancer.

To understand these conditions better and develop new treatments, or regenerate new tissue, researchers require models that very closely mimic the complex, three-dimensional environments found in human tissue.

As a natural material, collagen is ideal for these biomimetic applications. By shaping it into porous structures, collagen acts as a ‘scaffold’ on which cells and tissue can grow in three dimensions in predetermined forms, mimicking those found in the body.

̽��ֱ��idea of using collagen as a scaffold is not new, but the very high level of control that Cambridge researchers are able to achieve over its properties has made a huge range of clinical applications possible, including the repair of damaged joints or tissue, or accelerating the development of new therapies for cancer.

“There is an increasing need for improved materials that work with the systems in the body to regenerate healthy tissue, rather than just replacing what’s there with something synthetic,” said Professor Ruth Cameron of the Department of Materials Science and Metallurgy, who, along with Professor Serena Best, is working with researchers from across the ̽��ֱ�� to develop the scaffolds for a range of clinical applications. “You’re trying to help the body to heal itself and produce what it needs in order to do that.”

To build the scaffolds, the researchers begin with a solution of collagen and water and freeze it, creating ice crystals. As the collagen cannot incorporate into ice, it gathers around the edges of the crystals. When the pressure around the ice is dropped to very low levels, it converts directly from a solid to vapour, leaving the collagen structure behind. By precisely controlling how the ice crystals grow as the water freezes, the researchers are able to control the shape and properties of the resulting collagen scaffold.

By adding small groups of amino acids known as peptide sequences to the surface of the scaffold at different points, the way in which the collagen interacts with the growing cells changes, altering the potential uses for the scaffold. ̽��ֱ��peptide sequences signal certain cells to bind to the scaffold or to each other, while signalling other cells to migrate. Collectively, these signals direct the scaffold to form a certain type of tissue or have a certain type of biological response.

“ ̽��ֱ��scaffolds are a three-dimensional blank canvas – they can then be used in any number of different ways,” said Cameron, who is funded by the European Research Council. “They can be used to mimic the way in which natural tissue behaves, or they can be directed to form different sized or sequenced structures.”

̽��ֱ��technology has already gone from the laboratory all the way to patients, first as Chondromimetic, a product for the repair of damaged knee joints and bone defects associated with conditions such as osteoarthritis, trauma or surgery. By adding calcium and phosphate to the scaffold to mimic the structure of bone, it helps regenerate bone and cartilage. Chondromimetic has been through clinical trials and has received its CE mark, enabling its sale in Europe.

In future, the scaffolds could also see use as a treatment for cardiac disease. Working with Professor Richard Farndale from the Department of Biochemistry and Dr Sanjay Sinha from the Department of Medicine, and supported by funding from the British Heart Foundation, Best and Cameron are developing the scaffolds for use as patches to repair the heart after a heart attack.

Heart attacks occur when there is an interruption of blood to the heart, killing heart muscle. ̽��ֱ��remaining heart muscle then has to work harder to pump blood around the body, which can lead to a thickening of the heart wall and potential future heart failure.

By modifying the collagen scaffolds with the addition of peptide sequences, they could be used to grow new heart cells to ‘patch’ over areas of dead muscle, regenerating the heart and helping it function normally. Cells could be taken directly from the patient and reprogrammed to form heart cells through stem cell techniques.

While the work is still in its early stages, the scaffolds could one day be an important tool in treating coronary heart disease, which is the UK’s biggest killer. “These scaffolds give cells a foothold,” said Farndale, who is working with Sinha to characterise the scaffolds so that they encourage heart cells to grow. “Eventually, we hope to be able to use them, along with cells we’ve taken directly from the patient, to enable the heart to heal itself following cardiac failure.”

Another potentially important application for the scaffolds is in breast cancer research. By using them to grow mimics of breast tissue, the scaffolds could help accelerate the development of new therapies. Working with Professor Christine Watson in the Department of Pathology, Best and Cameron are fine-tuning the scaffolds so that they can be used to create three-dimensional models of breast tissue. If successful, this artificial breast tissue could assist with the screening of new drugs for breast cancer, reduce the number of animals used in cancer research and ultimately lead to personalised therapies.

“This is a unique culture system,” said Watson. “We are able to add different types of cells to the scaffold at different times, which no-one else can do. Better models will make our work as cancer researchers much easier, which will ultimately benefit patients.”

Like breast tissue, blood platelets also require a very specific environment to grow. Dr Cedric Ghevaert of the Department of Haematology is working with Best and Cameron to use the scaffold technology to create a bone-like niche to grow bone marrow cells, or megakaryocytes, for the production of blood platelets from adult stem cells. In theory, this could be used to produce platelets as and when they are needed, without having to rely on blood donations.

“ ̽��ֱ��technology for culturing the cells is actually quite generic, so the range of applications it could be used for in future is quite broad,” said Best. “In terms of clinical applications, it could be used in almost any situation where you’re trying to regenerate tissue.”

“In some senses, it can be used for anything,” added Cameron. “As you start to create highly organised structures made up of many different types of cells – such as the liver or pancreas – there is an ever-increasing complexity. But the potential of this technology is huge. It could make a huge difference for researchers and patients alike.”

Miniature scaffolds made from collagen – the ‘glue’ that holds our bodies together – are being used to heal damaged joints, and could be used to develop new cancer therapies or help repair the heart after a heart attack.

We are able to add different types of cells to the scaffold at different times, which no-one else can do

Christine Watson

Jennifer Ashworth

Collagen scaffold imaged using X-ray microtomography to reveal its 3D structure

Yes

From athletes to couch potatoes: humans through 6,000 years of farming

amb206 — Tue, 08 Apr 2014 09:00:10 +0000

Human bones are remarkably plastic and respond surprisingly quickly to change. Put under stress through physical exertion – such as long-distance walking or running – bones gain in strength as the fibres are added or redistributed according to where strains are highest. ̽��ֱ��ability of bone to adapt to loading is shown by analysis of the skeletons of modern athletes, whose bones show remarkably rapid adaptation to both the intensity and direction of strains.

Because the structure of human bones can inform us about the lifestyles of the individuals they belong to, they can provide valuable clues for biological anthropologists looking at past cultures. Research by Alison Macintosh, a PhD candidate in Cambridge ̽��ֱ��’s Department of Archaeology and Anthropology, shows that after the emergence of agriculture in Central Europe from around 5300 BC, the bones of those living in the fertile soils of the Danube river valley became progressively less strong, pointing to a decline in mobility and loading.

Macintosh will present some of her results at the Annual Meeting of the American Association of Physical Anthropologists in Calgary, Alberta on 8-12 April, 2014. She will show that mobility and lower limb loading in male agriculturalists declined progressively and consistently through time and were more significantly affected by culture change in Central Europe than they were in females.

Work published by biological anthropologist Dr Colin Shaw (also Cambridge ̽��ֱ��) has enabled Macintosh to interpret this male decline in relation to Cambridge ̽��ֱ�� students. Using Shaw’s study of bone rigidity among modern Cambridge ̽��ֱ�� undergraduates, Macintosh suggests that male mobility among earliest farmers (around 7,300 years ago) was, on average, at a level near that of today’s student cross-country runners. Within just over 3,000 years, average mobility had dropped to the level of those students rated as sedentary, after which the decline slowed.

“Long-term biomechanical analyses of bones following the transition to farming in Central Europe haven’t been carried out. But elsewhere in the world they show regional variability in trends. Sometimes mobility increases, sometimes it declines, depending on culture and environmental context. After the transition to farming, cultural change was prolonged and its pace was rapid. My research in Central Europe explores whether – and how – this long term pressure continued to drive adaptation in bones,” said Macintosh.

Archaeological evidence has shown that the gradual intensification of agriculture was accompanied by rising production and complexity of metal goods, technological innovation and the extension of trade and exchange networks. “These developments are likely to have brought about changes in divisions of labour by sex and socioeconomic organisation as men and women began to specialise in certain tasks and activities – such as metalworking, pottery, crop production, tending and rearing livestock,” said Macintosh.

“I’m interested in how the skeleton adapted to people's specific behaviours during life, and how this adaptation can be used to reconstruct long-term changes in behaviour and mobility patterns with cultural diversification, technological innovation, and increasingly more complex and stratified societies since the advent of farming.”

As a means of tracking changes in the structure of bones over time, Macintosh laser-scanned skeletons found in cemeteries across Central Europe, concentrating in particular on an analysis of engineering-based cross-sectional geometric properties as measures of the loading imposed on the lower limb bones during life. Her research took her to Germany, Hungary, Austria, the Czech Republic and Serbia. ̽��ֱ��earliest skeletons she examined date from around 5300 BC and the most recent from around 850 AD – a time span of 6,150 years.

Using a portable desktop 3D laser surface scanner to scan femora and tibiae, she found that male tibiae became less rigid and that bones in both males and females became less strengthened to loads in one direction more than another, such as front-to-back in walking. These findings all indicate a drop in mobility. In other words, it is likely that the people to whom the skeletons belonged became, over generations, less intensely active and probably covered less distance, or carried out less physically demanding tasks, than those who had lived before them.

“Both sexes exhibited a decline in anteroposterior, or front-to-back, strengthening of the femur and tibia through time, while the ability of male tibiae to resist bending, twisting, and compression declined as well,” said Macintosh.

“My results suggest that, following the transition to agriculture in Central Europe, males were more affected than females by cultural and technological changes that reduced the need for long-distance travel or heavy physical work. This also means that, as people began to specialise in tasks other than just farming and food production, such as metalworking, fewer people were regularly doing tasks that were very strenuous on their legs."

Although there was some evidence for declining mobility in females as well, trends were inconsistent through time in most properties. Macintosh believes that this variation may indicate that women in these early farming cultures were performing a great variety of tasks – multi-tasking, in fact – or at least undertaking fewer tasks necessitating significant lower limb loading. There is evidence from two of the earliest cemeteries studied that females were using their teeth in processing activities to carry out tasks unlikely to have loaded their lower limbs much.

Interesting comparisons can be made between the archaeological evidence from Central European skeletons dating from around 7,300-1,150 years ago and data from modern farming populations elsewhere in the world.

A study by Panter-Brick in 1996 found that relative workload (as exhibited by time allocation and energy expenditure) between males and females in modern farming populations is much more variable than in foraging groups. As in early Central European farming communities, higher physical activity is recorded among males than females in Indian and Nepalese farming communities, but females have a higher relative workload than males in farming communities in the Upper Volta and the Gambia.

“This variability in the sexual division of labour in living agro-pastoralist groups shows the importance of context, ecology, and various cultural factors on sex differences in physical activity. So it is important when studying long-term trends in behavioural change between the sexes that the geographic region is kept small, to help control for some of this variability,” said Macintosh.

Female skeletons showed a major change in femoral bending and torsional rigidity from the Bronze Age into the Iron Age – between about 1450 BC and 850 BC in the samples studied – when women had the strongest femora of all the females examined in the study. This could be because the Iron Age sample included skeletons of Hungarian Scythians, a group for whom large animal husbandry, horsemanship and archery were particularly important. Scythian females are thought to have performed heavy physical work and were known to participate in at combat.

“However, if this high Iron Age female bone strength in the femur was due to high mobility, it would also probably be visible in the tibia as well, which it was not. In that case, it could be something other than mobility that is driving this Iron Age female bone strength, possibly a difference in body size or genetics,” said Macintosh.

Because the skeleton holds a record of the loading it experiences during life, it can provide important clues as to the behaviour of past people through prolonged cultural change. Overall, in the first 6,150 years of farming in Central Europe, the prosperity generated by intensive agriculture drove socioeconomic change and allowed for people to specialise in tasks other than food production.

Macintosh said: "In Central Europe, adaptations in human leg bones spanning this time frame show that it was initially men who were performing the majority of high-mobility tasks, probably associated with tending crops and livestock. But with task specialisation, as more and more people began doing a wider variety of crafts and behaviours, fewer people needed to be highly mobile, and with technological innovation, physically strenuous tasks were likely made easier. ̽��ֱ��overall result is a reduction in mobility of the population as a whole, accompanied by a reduction in the strength of the lower limb bones."

Inset images: Cambridge ̽��ֱ�� cross-country runners (Cambridge ̽��ֱ�� Hare & Hounds); 3D model of an Early Neolithic femur; Bronze Age infant urn burial from Ostojićevo, National Museum of Kikinda in Serbia; wheatfield in modern day Kikinda, northern Serbia (all Alison Macintosh)

Research into lower limb bones shows that our early farming ancestors in Central Europe became less active as their tasks diversified and technology improved. At a conference today, Cambridge ̽��ֱ�� anthropologist Alison Macintosh will show that this drop in mobility was particularly marked in men.

My results suggest that, following the transition to agriculture in Central Europe, males were more affected than females by cultural and technological changes.

Alison Macintosh

Moravian Museum

Early Neolithic 35-40 year old male from Vedrovice, Czech Republic

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Yes

Solved: two of the historic riddles of horse racing

amb206 — Sat, 02 Jun 2012 08:15:24 +0000

A team of researchers examining DNA extracted from the skeletons of historic horses in order to throw light on the origin of diseases found in modern horses have, in the course of their work, solved some of the mysteries that have long puzzled the horse-racing world.

̽��ֱ��researchers' meticulous analysis answers the question of which of two horses actually won the Epsom Derby of 1880, revealing that the winner was running under the name of another horse. ̽��ֱ��same study has also led to the authentication of the 220-year-old skeleton of Eclipse, a legendary name in racing worldwide.

̽��ֱ��project – published in the current issue of the journal Archaeometry – involved not just laboratory work to analyse the DNA contained in bones, hair and blood of 300 living Thoroughbred horses but also an examination of historic archives held in Cambridge ̽��ֱ�� Library and close scrutiny of some of the most iconic paintings of horses.

̽��ֱ��research project was led jointly by Dr Mim Bower of the McDonald Institute for Archaeological Research, ̽��ֱ�� of Cambridge, who is an expert in the domestication of horses in pre-history, and a team from the Royal Veterinary College, including members of the Structure and Motion Group.

“ ̽��ֱ��purpose of the research was to develop tools that will help us understand the genetic history of the Thoroughbred horse – and, in particular, to discover when certain catastrophic genetic diseases might have entered the gene pool,” said Dr Bower. “Knowledge of the history of these diseases will help us in improving the health of living racehorses.”

̽��ֱ��Epsom Derby, to be run today, is one of the great classics of British racing. In the race of June 1880, a horse named Bend Or crossed the finishing line a whisker ahead of his rival, Robert the Devil. Celebrations turned sour when the owners of Robert the Devil claimed that Bend Or was running under the wrong name and was in fact a horse called Tadcaster. They argued that the two had been confused as yearlings - and that Robert the Devil was therefore the bona fide winner.

Bend Or and Tadcaster came from the Duke of Westminster’s Eaton Stud in Cheshire. With the same sire but out of two different dams, the three-year-olds looked strikingly similar – though the dam of the horse running in the Derby as Bend Or came from a lineage that had never won a race and the dam of the horse known as Tadcaster came from a winning line.

At a stewards’ inquiry the owners of the two horses – who had long been arch enemies - argued their cases. ̽��ֱ��inquiry found for the owners of Bend Or who went on to stand at stud and, on the basis of his Derby win, made the Duke of Westminster a small fortune. In a twist worthy of a Dick Francis thriller, one of the stud grooms who had handled the two horses as youngsters was reported to have confessed on his deathbed that the two animals had been confused – but he had been dismissed by the Duke of Westminster so his word was doubted.

Samples of DNA taken from the skeleton of Bend Or, which is archived in the Natural History Museum, were shown to match that of the living relatives of Tadcaster, proving almost without doubt that the horse running under the name Bend Or in the Derby of 1880 was indeed Tadcaster.

̽��ֱ��same team of researchers have also looked at the DNA of Eclipse, a chestnut stallion named after the solar eclipse of 1 April 1764, during which he was foaled. Bred by the Duke of Cumberland (known as the Butcher of Culloden), he easily won all 18 of the races in which he was entered, inspiring the phrase “Eclipse first, the rest nowhere”. He was immortalised by George Stubbs who painted several portraits of him, the most famous of which hangs in the Jockey Club’s Newmarket offices.

Once retired from racing, Eclipse became a phenomenal success at stud, siring more than 300 winners. Some 95 per cent of modern Thoroughbreds have him in their ancestry. “His descendants include Desert Orchid, Shergar, Red Rum, Pharlap and Northern Dancer to name just a few,” said Dr Bower.

̽��ֱ��racing world was keen to discover the secret of Eclipse’s awesome speed and on his death in 1789 an autopsy took place. Performed by a French veterinary surgeon called Vial de Saint Bel and thought to have been the first-ever formally-documented animal autopsy in the UK, the procedure revealed that Eclipse had a massive heart – at least 25 per cent larger than average. His large heart, combined with a physique that gave his paces tremendous scope, is thought to be the reason for his outstanding speed on the racecourse.

During the autopsy detailed drawings were made of Eclipse’s physiology and measurements of his bones were noted. These records are held by Cambridge ̽��ֱ�� Library together with early volumes of private and national studbooks (including the General Stud Book) going back to the 17^th century. Vial’s autopsy led to the foundation of the London Veterinary College (now ̽��ֱ��Royal Veterinary College) and Vial became the first Principal of the College on 8 April 1791.

Dr Bower said: “ ̽��ֱ��records of this early autopsy represent a vital historical resource for pedigree research which we use to trace the spread of desirable or undesirable genetic traits, for example. Today, the identity and parentage of every Thoroughbred horse is verified by genetic typing. In the past, records relied on the accuracy of recording at each of the Thoroughbred foundation studs.

“However, our research has shown that early Stud Book records are considerably more accurate than previously thought, and that errors, where they exist, are as a result of a lack of understanding of the precise biological modes of inheritance in the past. For example, fraternal sisters being recorded as part of the same maternal lineage, despite sharing a father rather than a mother.”

Eclipse’s skeleton was put on display as a curiosity and later transported up and down Britain, packed into boxes and reassembled at different destinations. It was eventually acquired by the Royal Veterinary College, where it is now on display in its resource centre, known as the Eclipse Building.

It has always been thought that the skeleton of Eclipse, if authentic at all, was likely to have been a composite of bones from different horses including some from the famous stallion himself – and it did seem highly possible that over the years the bones had been confused. Rumour had it that the head, in particular, came from a different horse. ̽��ֱ��existence of five “Eclipse” hooves added to scepticism about the skeleton.

Now evidence from meticulous ancient DNA analysis, and cross referencing scientific findings with contemporary sources, indicate that the majority of the skeleton (including the head) is authentic. ̽��ֱ��authentication of the bones involved several strands of research which were undertaken in the laboratories of the McDonald Institute in Cambridge and the Royal Veterinary College in London.

“We matched the mitochondrial DNA taken from Eclipse’s skeleton with DNA taken from his direct female descendants, traced by referencing their lineage from the records contained in the volumes of the Stud Book, early historic studbooks and Bobinsky’s Thoroughbred breed tables, held in Cambridge ̽��ֱ�� Library,” said Dr Bower.

“We also matched the coat colour genes with the colours in Stubbs’s paintings. We looked at the stable isotopes across different elements of the Eclipse skeleton and matched high precision measurements of the skeleton with those taken at the time of the autopsy in 1789. ̽��ֱ��comparison of measurements was a real puzzle because the inch – which in England was based on three barley grains lying end to end - was not formally standardised until 1959.”

̽��ֱ��research that led to these discoveries has implications both for archaeo-geneticists and for veterinarians. It is thought that humans first domesticated wild horses at least 7,000 years ago. Ever since, horses have played a central role not just in everyday lives but also in the human imagination with the ultimate horse being the fine-tuned athlete of the racetrack.

“Archaeological finds such as chariot burials suggest that horses were selected for specific traits, such as speed and colour, and that humans were making sophisticated active choices about which animals, and therefore which desirable traits, they chose to proliferate,” said Dr Bower.

In the early days racing took place over long distances, typically four miles, with horses being tested for stamina as well as speed. Races were head to head with just two horses being run against each other, in multiple heats. ̽��ֱ��end of the 19th century saw the number of runners being increased and race distances being dramatically shortened. Short bursts of intense speed put a strain on a horse’s body with some horses beginning their racing careers at the age of two.

“Thoroughbred horses are elite athletes capable of impressive performances – but they are also prone to debilitating conditions such as bone fracture and tendon injury and exercise induced pulmonary haemorrhage, many of which are thought to have a genetic basis. Our study of elite horses from the past will help us trace the spread of genetic disorders into the present – and it’s also been fascinating to have some historic puzzles along the way,” said Dr Bower.

̽��ֱ��identity of the winner of the 1880 Epsom Derby – the classic race to be run today - was famously disputed. Now analysis of DNA from the bones of historic horses has solved the mystery conclusively - and has confirmed the authenticity of the skeleton of one of the most famous stallions of all time.

̽��ֱ��purpose of the research was to develop tools that will help us understand the genetic history of the Thoroughbred horse and discover when certain genetic diseases entered the gene pool.

Dr Mim Bower

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̽��ֱ��Flying Dutchman and Voltigeur by John F Herring Sr. (1795 - 1865)

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A lost world? How zooarchaeology can inform biodiversity conservation

lw355 — Fri, 10 Feb 2012 14:00:01 +0000

As dawn breaks, a Cantor’s Roundleaf bat flies through the lush rainforest canopy searching out its colony. Its home is the Great Cave of Niah, Sarawak, in northern Borneo, where it accompanies tens of thousands of other bats, careening through the cave after a night’s work hunting insects. It’s a scene that has probably been replicated daily for tens of thousands of years.

Evidence for the longevity of bat colonisation of the cave has been revealed through analysis of some 12,000 bat bones, as well as 1,400 bird bones, uncovered by archaeologists digging in Hell Trench at the West Mouth of the cave, and examined and dated by Cambridge zooarchaeologist Dr Chris Stimpson. His recently completed study, which was funded by the Natural Environment Research Council, suggests that bats have been living there for 50,000 years.

̽��ֱ��forest surrounding the Great Cave of Niah once blanketed the entire state of Sarawak, but today only pockets remain such as the Niah National Park, where the cave is located. Conservation efforts here and elsewhere in the world are faced with the challenge of how best to manage and conserve what is left of some of the most biologically diverse and complex habitats on Earth.

Stimpson, along with other zooarchaeologists around the world, believes he has something new to offer the debate: “Conservation efforts draw on relatively recent ecological evidence. To formulate effective priorities for biological conservation, zooarchaeology, or the study of ancient animal bones, can provide a remarkably long-range perspective. It can tell us something about the nature of animal communities before humans intensively modified their habitats, as well as provide a deeper understanding of the role that humans have played in structuring tropical forests across millennia.”

Tall, moisture-loving, closed-canopy forests form a band around the equator and have been described as of “disproportional importance” in driving patterns in global biodiversity and the global carbon cycle. ̽��ֱ��ambitious study begun by Stimpson will measure changes in animal communities in tropical forests over 50,000 years and across three continents.

̽��ֱ��bare bones

̽��ֱ��idea behind the new study grew out of Stimpson’s PhD research at the Great Cave as part of a major research project begun in 2000 under the leadership of Graeme Barker, Disney Professor of Archaeology and Director of the McDonald Institute for Archaeological Research in Cambridge. ̽��ֱ��long-term investigation, which was funded principally by the Arts and Humanities Research Council, involved a team of 40 archaeologists and environmental scientists from a dozen universities. ̽��ֱ��team found astonishing evidence for sophisticated methods used by early Modern Humans to exploit the rainforest as far back as 45,000 years ago, from specialist hunting techniques to the neutralisation of poisons.

Famously, the oldest reliably dated Modern Human fossil in Southeast Asia yet recorded, known as ‘Deep Skull’, had previously been discovered within the cave in the 1950s by Tom and Barbara Harrisson. As a result of Barker’s research, its age was confirmed as 37,000 years old.

“There had been some debate as to whether the rainforests were a major barrier to the dispersal of modern humans because of the difficulties of foraging in an environment where food is widely dispersed and ephemeral, and sometimes inaccessible in the canopy. But the findings in the Great Cave showed that they weren’t flailing around. They coped well, were thinking ahead and adapting to change,” said Stimpson.

Tropical forests such as the Niah National Park are often regarded as the world’s last ‘virgin landscapes’. Yet this runs contrary to Stimpson’s and others’ findings, as he explained: “These communities may have been subject to exploitation and modification by humans for thousands of years. Essentially, what we regard as ‘pristine’ ecosystems are in fact ‘degraded’ ecosystems. Zooarchaeology can help those involved in conservation efforts to understand how ecologically representative remnant stands of forest are."

After painstakingly analysing the vast number of animal bones found in the cave, Stimpson discovered that people were hunting hornbills at least 19,000 years ago and eating cave-dwelling fruit bats 42,000 years ago. He was able to identify bones from four species of hornbill, although only a single species remains in the forest today.

Using the distal part of the humerus bone (close to the elbow) as a taxonomic marker to differentiate between species of bat, Stimpson found that a colony of wrinkle-lipped bats, which may have numbered as many as three million individuals at its peak, had disappeared by the 17th century: “This may be because the colony was disturbed when people began to visit the cave regularly to collect the nests of cave swiftlets, whose edible nests were much prized as the main ingredient of bird’s nest soup,” he said.

By contrast, he found evidence to suggest the persistence of the Strategy I bats, a guild of bats that need closed-canopy forest to hunt. “If you lose the closed-canopy forest, then you lose this group of bats,” he explained. “This finding presents a robust case for the existence of closed-canopy rainforest for at least 50,000 years, putting starkly into perspective the fact that recent forest felling has reduced the forest by two thirds in the past 40 years.”

Looking for ‘lost worlds’

“Attempts to contextualise and quantify the extent of human impact on the biodiversity and resilience of the tropical forest are hampered by the lack of studies that consider tropical forests from millennial timescales,” Stimpson said. “Yet, such studies can provide benchmarks far deeper in time than ecological snapshots, which rarely approach 50 years in duration.

Although the title of the new research project, ‘A lost world? Zooarchaeology and biological conservation in the tropical forest biome’, tips its hat to Sir Arthur Conan Doyle’s tale of an expedition to a South American plateau where prehistoric animals still survive, it does so because it considers study sites at times before the recent intensive modification of habitats by humans. In other words, tropical forest communities that might now be considered ‘lost worlds’.

“I’m interested in what role humans have played as active predators in structuring the animal communities of tropical forest habitats and what implications this has for the animal communities we see today,” explained Stimpson, whose new research is funded by the McDonald Institute for Archaeological Research.

To do this, he is pulling together published zooarchaeological datasets from 26 studies at archaeological sites in Central and South America, Central Africa and Southeast Asia, with a view to eventually increasing this to 40 datasets. Each dataset represents a faunal inventory listing all of the different animal groups that are evident from the thousands of bones retrieved in the course of excavation. He will then compare this with the fauna that exist in the region today.

Because the project is so broad in its spatial and temporal coverage, it will allow Stimpson to characterise the direct and indirect effects of human hunting behaviour in geographical regions over millennia. He will be able to ask whether trends exist in the spectrum of targeted animals and what ecological role these animals play in tropical fores

As his studies progress, Stimpson will work closely with conservation scientists in Cambridge: “I’m trying to knit biological conservation and archaeology together.”

̽��ֱ��results, he believes, will provide a powerful tool to improve current understanding of ecosystem change in response to anthropogenic pressures. Crucially, the long-term benchmark data produced by the project will be of direct relevance to conservation initiatives working in the tropical forest biome; his aim, as he explained, is to ask: “How can we utilise these data in the best possible way to inform conservation priorities for protection?”

A new study of tropical forests will provide a 50,000-year perspective on how animal biodiversity has changed, explored through an archaeological investigation of animal bones.

̽��ֱ��study of ancient animal bones can provide a remarkably long-range perspective. It can tell us about the nature of animal communities before humans intensively modified their habitats.

Dr Chris Stimpson

Chris Stimpson

Ancient bat bones

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Yes

Back ache: it’s been a pain for millions of years

ns480 — Mon, 21 Mar 2011 09:40:28 +0000

̽��ֱ��high incidence of back pain apparent today is often blamed on our lazy lifestyles: we sit at computers, watch television, travel by car and eat too much. But debilitating back ache is nothing new: it dates back millions of years to an era long before screens and sofas, according to a Cambridge ̽��ֱ�� researcher who is looking at the fossil record of human bones.

In a talk called "Four Million Years of Back Pain" on 25 February, Dr Asier Gomez-Olivencia will present the latest results of his research on the damaged spine of an early hominin called Homo heidelbergensis. He will set this in the context of the diseases evident in the fossil record of the hominin spine from australopithecines to Neanderthals - a time span stretching from 4.4 million to 30,000 years ago.

Gomez-Olivencia will also discuss the possibility that disabled members of early human communities may have been looked after by the rest of the group for significant periods of time, confounding popular stereotypes of these societies as brutal and uncaring.

Found among the bones of around 28 individuals at a site called Sima de los Huesos (pit of bones) in northern Spain, the almost-complete lumbar spine caused huge excitement when it was carefully reconstructed from fragments discovered during different field seasons by a team of scientists from the Centro Mixto de Evolución Humana in Burgos.

̽��ֱ��spine comes from the same individual as a pelvis found back in 1994, two years after the site yielded three complete crania. These finds merited the front cover of the prestigious scientific journal Nature as they pushed back the Neanderthal lineage into the Middle Pleistocene (around 500,000 years ago) and helped to clarify human evolution in that period.

While the tough bone material of human teeth and long bones is more likely to survive, human vertebrae are more fragile and prone to break and finally disappear, making them tantalisingly rare in the fossil record. ̽��ֱ��lumbar spine found in Sima de los Huesos, known as SH1, is more or less intact.

Examination of the morphology of the pubis symphysis shows that the bones come from a man of around 45 years (distinctly elderly for the time) who lived more than half a million years ago. ̽��ֱ��way in which the bones developed (their morphology) and the way they changed due to wear and tear (their pathology) show that this individual is likely to have suffered severe back pain.

Back problems - which today account for almost half of absences from work and exert a heavy toll on the economy - are often considered to be a side effect of an "unnatural" life style. But the SH1 spine adds to other fossil evidence that vertebral pathologies have been present in our history for millions of years. Living very differently to us, our ancestors suffered from back problems comparable to the conditions that cause us so much misery.

Dr Gomez-Olivencia is matching the morphology and pathology of the SH1spine to modern spines showing similar lesions. "It appears that we are looking at the spine of a man who had several different problems, including the inversion of the curvature of the back, spondylolisthesis, and Baastrup disease - which are associated with pain today," he said.

Homo heidelbergensis were nomadic hunter gatherers, relying on animals such as red deer and horses for food, and a damaged spine would have made hunting impossible. ̽��ֱ��survival of a man with limited mobility suggests that some individuals may have been looked after by others, or have found alternative roles in the community.

"It's likely that communities differed in their responses to disabilities so we can't say for certain that the SH1 individual was cared for by the group or that this was typical - but it's interesting to note that this is not the only individual that suffered pathologies in this site," said Dr Gomez-Olivencia.

Not only are Homo heidelbergensis likely, like us, to have suffered back pain. ̽��ֱ��results of a study published by Spanish scientists suggest that our female ancestors experienced another health hazard often regarded as relatively modern - difficult and painful births.

When the human pelvis adapted to an upright position, its modified configuration "competed" with the need to give birth to infants with large heads. A comparison of the shape of the SH1 pelvis with human fossil pelvises known to be female from around the world reveals that the difference between sexes of the fossil specimens parallels those of modern males and females. This discovery suggests that our female ancestors had tricky and life-threatening deliveries.

Research by a Cambridge archaeologist shows that back pain caused untold misery long before we started staring into screens and slumping on sofas.

It's likely that communities differed in their responses to disabilities so we can't say for certain that the SH1 individual was cared for by the group or that this was typical.

Dr Asier Gomez-Olivencia

ksmithdc from Flickr

backache

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