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Pigeon wingman rules
Pete Wilton | 27 Sep 13 | 0 comments
Travelling in flocks may make individual birds feel secure but it raises the question of who decides which route the group should take.
Mathematical models developed by scientists suggest that a simple set of rules can help flocks, swarms, and herds reach a collective decision about where to go. But investigating how this really works, especially with animal groups in flight, is extremely challenging.
A new study led by Oxford University scientists, reported in the Journal of the Royal Society Interface, has used the sort of high-resolution GPS technology normally reserved for extreme sports to look at how homing pigeons make decisions on the wing.
I asked lead author Benjamin Pettit of Oxford University's Department of Zoology about the research and what it tells us about the rules of the fly game…
OxSciBlog: What are the advantages of flying in a flock?
Benjamin Pettit: For pigeons, the main advantage of flying in a flock is to lower the risk of being eaten. Therefore pigeons in flocks need to coordinate their behaviour to stay together - something they have in common with many other animals. In addition to safety, there might be navigational advantages to flying as a flock. For example, when a flock of pigeons flies home together, the route they take will potentially combine navigational knowledge of many birds.OSB: How are pigeons able to 'share information' in flight?
BP: Until now, nobody has directly measured how pigeons respond to each other's movements in flight, but from mathematical simulations we know that flocking can arise from simple rules based on visual cues, namely 'stay with the group,' 'avoid collisions,' and 'head in the same direction as those around you.'If each bird is also paying attention to navigational cues, like familiar landmarks, then flocking rules will be effective at sharing information within the flock. What we do know from previous data on pigeon flocks is that there isn't always an equal, two-way exchange of information, and instead some pigeons have more of a leadership role within the flock.
OSB: How did you explore group navigation behaviour?
BP: We studied the simplest flocking scenario of two pigeons flying home together. Each pigeon had its own preferred homing route, which meant we could test how each pigeon's preference factored into the pair's route, and also find out how the group decision arises from the pigeons' momentary interactions during the flight.The pigeons carried lightweight, high-resolution GPS loggers, which were actually designed for extreme sports. It was also the right technology for racing pigeons. Working together with mathematical biologists at Uppsala University in Sweden, we created a simulation based on the interaction rules that we inferred from the GPS data, which was a useful tool for studying pigeons' group decisions.
OSB: What did you find out about the rules governing this behaviour?
BP: Pigeons responded to each other by adjusting their speeds and making small turns, maintaining a close, side-by-side configuration most of the time. A pigeon was sensitive not only to its neighbour's position, as has been observed in fish schools, but also to the direction its neighbour was headed.The flocking behaviour was stronger toward a neighbour in front than behind, which means that a faster pigeon that consistently gets in front has more influence over the pair's route. This simple leadership mechanism based on speed is something we investigated with a combination of the data and the simulation.
Our findings show how real bird flocks compare to the 'rules of motion' postulated in simulations over the past three decades.
OSB: How might your findings help us understand group navigation in other animals?
BP: First of all, we found that persistent leadership-follower relationships observed in nature are not necessarily something complicated that requires animals to recognise each other and assess each other's ability. The mechanism can be as simple as a difference in speed.Second, we found some similarities with fish in terms of how flocks/schools are formed, but also some differences that are likely due to the biomechanics of flight versus swimming.
The pairwise configuration of pigeons is similar to that observed in starling flocks. Rather than converging on a 'universal' flocking rule, different animal lineages have their own solutions for collective motion, which affect the shapes of schools, herds, and flocks. The particular interaction rules will also affect how information passes through these groups from one animal to another.
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Hunting species: not just a numbers game
Pete Wilton | 24 Sep 13 | 0 comments
In the race to describe all of Earth's species before they go extinct it has been suggested that one species that is thriving is taxonomists.
Taxonomists are the people responsible for describing, identifying, and naming species – so far they have described around two million species. This could involve trekking into the jungle to discover new plants and animals but more often means poring over samples in existing collections and databases to unearth previously undescribed species.
'Taxonomic data, knowledge about species, underpins nearly every aspect of environmental biology including conservation, extinction, and the world's biodiversity hotspots,' explains Robert Scotland of Oxford University's Department of Plant Sciences.
If you want to describe all Earth's species before they vanish then the question of the taxonomy community's capacity, and the speed with which they can discover new species, becomes very important.
Some recent studies looking at trends in extinction counted the number of authors on each taxonomic paper and concluded that there was an expanding workforce of taxonomists chasing an ever diminishing pool of undescribed species. 'These findings contradict the prevailing view that there are six million species on Earth remaining to be discovered by an ever diminishing number of taxonomists, the so called 'taxonomic impediment',' Robert comments.
To test whether taxonomists were really a booming or endangered species, and what this might mean for species discovery, Robert and colleagues from Exeter University and Kew Gardens analysed data on the discovery of new plant species. A report of the research is published in the journal New Phytologist.
'What we found was that from 1970 to 2011 taxonomic botanists described on average 1850 new flowering plants each year, identifying a total of 78,000 new species,' Robert tells me. 'But while this period saw the number of authors describing new species increased threefold, there was no evidence for an increase in the rate of discovery.
'One recent idea is that species are becoming more difficult to discover and more authors are subsequently required to put in more effort to describe the same number of new species. We found no evidence for this as the lag period between a specimen being collected and subsequently described as a new species has increased.'
The team's study showed that, far from running out of new species, there are still around 70,000 new species of flowering plant waiting to be discovered. So why are taxonomy authors multiplying?
To get some context the researchers analysed the number of authors on papers in other subjects including botany, geology and astronomy over a similar period, 1970-2013, and then compared them to the data on taxonomy authors.
'We found that the increase in authors on taxonomy papers was in fact fairly modest compared to the 'author inflation' in other subjects including botany,' Robert explains. 'Our data show for geology that there were 1.8 authors per paper in 1975 but this has risen to 4.8 in 2013, and for astronomy, 1.6 authors per paper in 1970, 8.4 in 2013, so a fivefold increase.'
There could be many different reasons for author inflation; more interdisciplinary research, technological advances, the closer monitoring of performance indicators in scientific institutions that has led to the inclusion of students, lab assistants, junior staff and technical staff as authors on papers.
Robert comments: 'Using crude measures of author numbers to measure taxonomic capacity at a time of author inflation across all of science has the potential to be highly misleading for future planners and policy makers in this area of science.
'Our study found that in fact a very large number of new species are discovered and described by a very small number of prolific botanists, and more than 50% of all authors are only ever associated with naming a single species.
'It shows that there remain huge uncertainties surrounding our capacity to describe the world’s species before they go extinct.'
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Oxford's part in a new multiple sclerosis drug
Jonathan Wood | 18 Sep 13 | 0 comments
A highly effective new treatment for multiple sclerosis was approved yesterday by the European Medicines Agency, the regulator for drugs in Europe. The drug can offer people with early multiple sclerosis many more years free from worsening disability, and Oxford played an important role in the drug's development.
Professor Herman Waldmann was involved in the early discovery work with the antibody drug at Cambridge University and brought a significant proportion of the research to Oxford when he moved here in 1994.
Once in Oxford, his team worked on the manufacture of the drug, contributed important new understanding of how the drug worked, and investigated the drug's application in a number of disease areas.
Cambridge continued to lead the clinical trials of the new drug in multiple sclerosis, and it is these which have now seen the drug approved by the European regulator.
The newly approved drug is called alemtuzumab and is made by the drug firm Genzyme, which will market the drug under the brand name Lemtrada.
'We are very pleased and proud of this outcome,' said Professor Waldmann. 'In particular, we have great admiration for the neurology team in Cambridge, with whom we have worked on this project for so many years. Their commitment and focus has been exemplary, and this has been a good example of basic and clinical science collaboration at its best.'
Although now approved for use in the EU, it still remains to be determined whether this drug will become a common treatment option for NHS patients, as the drug has not yet been assessed by the National Institute for Health and Care Excellence (NICE) for multiple sclerosis.
Multiple sclerosis affects 2.5 million people worldwide and approximately 100,000 people between the ages of 20-40 years in the UK. The disease sees the patient's own immune system attack their nerve cells, resulting in symptoms including numbness, tingling, blindness and even paralysis. Although some recovery may occur, the majority of patients relapse and then see repeated relapsing and remitting stages. Current treatments require frequent administration and are only moderately effective, reducing the relapse rate by only approximately 30%.
Alemtuzumab has the potential to make a great difference to patients, in terms of a better quality of life and not having to take treatments continuously.
'It is the first drug for multiple sclerosis that only needs to be given for a short course to provide long-term benefit,' explained Professor Waldmann, though the drug does need to be given before the disease has progressed too much.
The drug offers people with multiple sclerosis an improvement in their ability to function in their daily lives, a significant slowdown of disease progression and fewer disease relapses, he says. 'It compares favourably in terms of efficacy to most of the current treatments.'
Alemtuzumab reboots the immune system by first depleting a key class of immune cells, called lymphocytes. The system then repopulates, leading to a modified immune response that no longer attacks myelin and nerves as foreign.
But in doing so, roughly one third of multiple sclerosis patients develop another autoimmune disease after alemtuzumab, mainly targeting the thyroid gland and more rarely other tissues especially blood platelets.
Dr Alasdair Coles of the University of Cambridge explains: 'Alemtuzumab offers people with early multiple sclerosis the likelihood of many years free from worsening disability, at the cost of infrequent treatment courses and regular monitoring for treatable side-effects.'
The Cambridge research team is currently investigating how to identify people who are susceptible to this side-effect and seeing whether this side-effect can be prevented.
It was soon after the Nobel laureates Cesar Milstein and George Kohler invented the technology for making large quantities of monoclonal antibodies at the Laboratory of Molecular Biology that Herman Waldmann and others in Cambridge produced the first monoclonal antibody for potential use as a medicine. This antibody, then called Campath-1H and now known as alemtuzumab, was subsequently licensed for the treatment of chronic lymphocytic leukaemia.
In the 1980s, the scientists also began to explore the drug's use in autoimmune diseases, which occur when the body's immune system mistakenly attacks healthy tissue.
'By applying the drug in leukaemia, vasculitis, bone marrow and organ transplantation, we learned lot about how to use it, and this was the background for the application in multiple sclerosis,' explained Professor Waldmann.
Through the 1990s, while Cambridge neurologists began to explore the use of alemtuzumab as a treatment for multiple sclerosis, the Therapeutic Antibody Centre at the University of Oxford led by Professor Waldmann – a unique facility at the time – permitted the development and manufacture of alemtuzumab for clinical trials.
And through this partnership between Oxford and Cambridge, it was determined how the drug worked and its advantages in multiple sclerosis became clear.
Professor Alastair Compston and Dr Coles of Cambridge University led the subsequent clinical research to develop alemtuzumab in partnership with Genzyme.
Professor Compston said: 'This announcement [by the European Medicines Agency] marks the culmination of more than 20 years' work, with many ups and downs in pursuing the idea that Campath-1H might help people with multiple sclerosis along the way. We have learned much about the disease and, through the courage of patients who agreed to participate in this research, now have a highly effective and durable treatment for people with active multiple sclerosis if treated early in the course.'
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Ash charges up volcanic lightning
Pete Wilton | 16 Sep 13 | 0 comments
The science of how rubbing a balloon on a woolly jumper creates an electric charge may help to explain how volcanoes generate lightning.
Volcanic plumes play host to some of the most spectacular displays of lightning on the planet but, whilst there are many theories, the exact mechanisms behind these natural light shows, and why some volcanoes see more lightning than others, are a mystery.
In a recent study published in Physical Review Letters researchers from Oxford University, and the Universities of Bristol and Reading, investigated what role volcanic ash particles rubbing together might play in making lightning bolts.
I asked Karen Aplin of Oxford University's Department of Physics, a co-author of the study, about volcanic lightning and how it can give insights into volcanoes on Earth and even other planets…
OxSciBlog: What do we think causes lightning in volcanic plumes?
Karen Aplin: Lightning in volcanic plumes is not completely understood, but there are several ideas about how it might work. Lightning is a giant spark that fires when large quantities of electric charge build up. Thunderclouds are made of water, ice and hail, and the electrification arises from collisions between light particles (ice) moving upwards in the cloud, and heavier water drops falling.One way lightning in volcanic plumes could be generated is from ash particles colliding with each other. This is similar to the electric charge that can be generated by rubbing a balloon on a jumper.
Another way lightning can occur in volcanic plumes is from some volcanoes, like Eyjafjallajökull in Iceland, that have glaciers on top of them. When the volcano erupts, the glacier melts, which both causes huge floods and makes a big cloud of ice and water that becomes mixed with the volcanic plume. This mixture of cloud and plume can generate volcanic lightning by ice, water, and ash collisions in what's called a 'dirty thunderstorm'.
OSB: How did you set out to study the role of ash particles?
KA: We were interested in measuring the electric charging from ash particles colliding with each other. To do this, we dropped small samples of ash through a tube and measured the electric charge on the ash when it lands on a detector at the bottom of the tube. As the ash falls it rubs against other ash particles, and transfers electric charge (like the jumper and the balloon).This experiment, carried out under controlled conditions in the lab at Oxford Physics, is the closest we can get to copying how the ash behaves in a volcanic plume. We took special care to make sure unwanted effects, such as the ash rubbing against the sides of its holder, were as small as possible so that we only measured the electric charge generated from the ash rubbing against itself.
The ash samples we tested were from the Icelandic volcanoes Grímsvötn and Eyjafjallajökull, and were generously given to us by the Icelandic Met Office. With the help of our colleagues in Earth Sciences and Geography at Oxford we measured the sizes of the ash particles, and sieved the ash to separate out the particles of different sizes, so we could understand how the size of the ash affected the electric charge transferred.
OSB: What do your results reveal about how variation in ash particles affects lightning?
KA: We found that some ash particles became more electrically charged than others, and that the size of the ash particles was important. If the particles have a wide range of sizes, they charge better than particles that are all of similar size.Particles with the biggest difference in size from the largest to the smallest charged best of all. This suggests that frictional charging from particles rubbing together will be quite efficient in the plume near the volcano, where lightning is observed.
We also found that ash from different volcanoes had different electrical properties. For example, the ash from Grímsvötn charged up much more easily than the ash from Eyjafjallajökull. This is particularly interesting, as the Grímsvötn eruption produced much more lightning than Eyjafjallajökull. We don’t yet know why this is, but our lab measurements may be a first step towards understanding what part the properties of the ash play in volcanic lightning.
OSB: How could these findings help in the remote sensing of volcanic activity?
KA: Firstly, motivated by the dramatic lightning from the Grímsvötn eruption, the Icelandic Met Office is experimenting with lightning detection to provide additional early warning of eruptions. A better understanding of how volcanic plumes become charged could reduce false detections of volcanic lightning, and perhaps provide more information on the progress of the eruption.Secondly, our results explain our previous curious observations, obtained with weather balloons, of electric charge within plumes distant from the volcano. This charge was unexpected, since the electricity on the particles when they were near the volcano should decay away relatively quickly.
Our results show that when the ash particles of different sizes rub against each other anywhere in the plume, they become electrified. Knowing that all plumes are very likely to be charged, no matter how far away from the volcano, means that we can start to develop new techniques to distinguish between clouds and volcanic plumes, the separation of which is crucial in mitigating hazards to aircraft.
OSB: What can they tell us about volcanism on other planets?
KA: Our findings are not limited to just terrestrial volcanoes. They are another step towards confirming that volcanic lightning occurs in planetary atmospheres.One reason why this is important is that chemicals generated by lightning have been linked to the origins of life, so any planet that might have lightning may yield fundamental answers to some of the biggest questions there are. Electromagnetic signals from lightning also look promising for detecting volcanic activity as space probes fly past.
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Battle for the bees
Pete Wilton | 12 Sep 13 | 0 comments
Bees and other pollinators aren't just pretty creatures, they work for us.In 2009 it was estimated that services provided by pollinators are worth an annual £510m in crops to the UK. That's why declines in many insect pollinator populations are a worry for economists and politicians as much as ecologists.
Take the bumblebee: the number of species has declined across Europe in the last 60 years and in Britain at least two species are thought to have gone extinct. Many other specialist pollinators are threatened and no one knows what effect this will have on overall pollination services.
There have been many theories about what's causing the decline and how we might halt it: recently insecticides called neonicotinoids have been suggested as a prime suspect but parasitic mites (Varroa destructor) and fungal disease (Nosema ceranae) have also been in the frame, not to mention the widespread destruction of pollinator-friendly habitats, such as wildflower meadows.
At an event in the Houses of Parliament this afternoon, UK politicians can find out about the current evidence concerning pollinator decline and what might be done to stop it. The event and accompanying POSTnote are the work of Rory O'Connor, a DPhil student at Oxford University's Department of Zoology and the NERC Centre for Ecology and Hydrology.
'The idea of POSTnotes is that they are an unbiased source of the best information about a topic and explain the science in a clear and understandable way,' Rory tells me. 'This is challenging when it comes to pollinator decline as there are opposing views, with neonicotinoids being a particularly controversial issue. What I had to do was go back through all the scientific evidence, summarise it, and then present it in just four pages.'
One of the big problems is how much we still don't know about pollinator populations. 'How do you monitor insect pollinator populations effectively? Which pollinators provide pollination services to which crops or wildflowers? In a lot of cases we don't know,' Rory explains. 'There's already some ongoing research into this but it's still early days and it's a fast-changing area, but then this is part of what makes it exciting to investigate!'
Rory's usual area of study is butterflies, so branching out to research a wide range of pollinators was quite a departure. The opportunity to work in Westminster came when he was awarded a British Ecological Society Fellowship at POST.
The event and publication of the note marks the end of his Fellowship but Rory comments that he's learnt a lot from it: 'My writing has improved, as has my analytical thinking and ability to synthesise a lot of complicated information – all particularly useful skills to hone for when I'm writing up my thesis. The simple but important things, like my confidence in asking questions and talking to people about my work and ideas, have also improved. I've also learnt a lot about the tremendously important world of insect pollinators.'
So what have we learnt about how to save the bees?
As well as the need to improve our fundamental knowledge of the role of insect pollinators and monitoring populations, the evidence Rory has gathered suggests that conserving and creating pollinator-friendly habitats could be crucial in providing refuges for at-risk species to feed and nest.
One answer could be to build on and extend current initiatives such as the UK government's 12 Nature Improvement Areas, Wildlife Trust's Living Landscapes, and the B-Lines project in Yorkshire, where farmers create corridors linking pollinator habitats. England's 402,000 km of hedgerows could also be used to provide new habitats.
Let's hope that the Westminster hive-mind can find an answer to the question of how to protect such valuable and productive insect species.
Detailed view of bumblebee on a flower image courtesy of Shutterstock.
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Hens may select sperm for healthier offspring
Pete Wilton | 06 Sep 13 | 0 comments
Female red junglefowl, the wild ancestor of the domestic chicken, may be able to optimise the immunity of their offspring by selecting sperm after mating with different males.
That's the conclusion from a study led by Oxford University researchers published in this week's PNAS.
'In natural populations, males can coerce females and selecting sperm after mating with multiple males is a safer way to control offspring paternity for a hen,' explains Dr Tom Pizzari of Oxford University’s Department of Zoology, one of the research team.
Whilst previous work has demonstrated that hens are able to select against the sperm of related males after mating, quite what triggers this response is a mystery.
The team focused their efforts on the Major Histocompatibility Complex (MHC), a gene complex that plays a key role in immune responses. 'Similarity at the MHC between two individuals is often a good proxy for their overall relatedness,' Tom tells me.
In the study the team looked for evidence of sperm selection after both natural matings and artificial insemination. Whilst there was strong evidence for sperm selection in the natural matings, evidence of this occurring with artificial insemination was much weaker.
'During natural mating hens appear to be able to assess their relatedness and genetic similarity with prospective partners,' comments Tom. 'One possibility is that the genetic profile of an individual at the MHC may be associated with olfactory cues, but the extent to which olfactory cues mediate kin recognition in birds remains unclear.'
The team's results suggest that hens may preferentially retain the sperm of males with a MHC different from their own. This could mean that rather than selecting sperm merely to avoid the risk of inbreeding, hens may select sperm in order to optimise the MHC diversity of their offspring, which translates into better immunity against a wider range of pathogens.
The findings are not just relevant to junglefowl or chickens:
'Mechanisms of female sperm selection are widespread, yet their functional significance has remained elusive,' Tom tells me. 'The results of our study suggest that some of these mechanisms may have evolved to allow females to optimise the genetic diversity of their offspring after mating with multiple males. These results may therefore have relevance for breeding programmes in animal productions and conservation biology.'
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Silence in the sky – but why?
Stuart Gillespie | 23 Aug 13 | 0 comments
Scientists as eminent as Stephen Hawking and Carl Sagan have long believed that humans will one day colonise the universe. But how easy would it be, why would we want to, and why haven't we seen any evidence of other life forms making their own bids for universal domination?
A new paper by Dr Stuart Armstrong and Dr Anders Sandberg from Oxford University's Future of Humanity Institute (FHI) attempts to answer these questions. To be published in the August/September edition of the journal Acta Astronautica, the paper takes as its starting point the Fermi paradox – the discrepancy between the likelihood of intelligent alien life existing and the absence of observational evidence for such an existence.Dr Armstrong says: 'There are two ways of looking at our paper. The first is as a study of our future – humanity could at some point colonise the universe. The second relates to potential alien species – by showing the relative ease of crossing between galaxies, it makes the lack of evidence for other intelligent life even more puzzling. This worsens the Fermi paradox.'
The paradox, named after the physicist Enrico Fermi, is something of particular interest to the academics at the FHI – a multidisciplinary research unit that enables leading intellects to bring the tools of mathematics, philosophy and science to bear on big-picture questions about humanity and its prospects.
Dr Sandberg explains: 'Why would the FHI care about the Fermi paradox? Well, the silence in the sky is telling us something about the kind of intelligence in the universe. Space isn't full of little green men, and that could tell us a number of things about other intelligent life – it could be very rare, it could be hiding, or it could die out relatively easily. Of course it could also mean it doesn't exist. If humanity is alone in the universe then we have an enormous moral responsibility. As the only intelligence, or perhaps the only conscious minds, we could decide the fate of the entire universe.'
According to Dr Armstrong, one possible explanation for the Fermi paradox is that life destroys itself before it can spread. 'That would mean we are at a higher risk than we might have thought,' he says. 'That's a concern for the future of humanity.'
Dr Sandberg adds: 'Almost any answer to the Fermi paradox gives rise to something uncomfortable. There is also the theory that a lot of planets are at roughly at the same stage – what we call synchronised – in terms of their ability to explore the universe, but personally I don’t think that’s likely.'
As Dr Armstrong points out, there are Earth-like planets much older than the Earth – in fact most of them are, in many cases by billions of years.
Dr Sandberg says: 'In the early 1990s we thought that perhaps there weren’t many planets out there, but now we know that the universe is teeming with planets. We have more planets than we would ever have expected.'
A lack of planets where life could evolve is, therefore, unlikely to be a factor in preventing alien civilisations. Similarly, recent research has shown that life may be hardier than previously thought, weakening further the idea that the emergence of life or intelligence is the limiting factor. But at the same time – and worryingly for those studying the future of humanity – this increases the probability that intelligent life doesn't last long.
The Acta Astronautica paper looks at just how far and wide a civilisation like humanity could theoretically spread across the universe. Past studies of the Fermi paradox have mainly looked at spreading inside the Milky Way. However, this paper looks at more ambitious expansion.
Dr Sandberg says: 'If we wanted to go to a really remote galaxy to colonise one of these planets, under normal circumstances we would have to send rockets able to decelerate on arrival. But with the universe constantly expanding, the galaxies are moving further and further away, which makes the calculations rather tricky. What we did in the paper was combine a number of mathematical and physical tools to address this issue.'
Dr Armstrong and Dr Sandberg show in the paper that, given certain technological assumptions (such as advanced automation or basic artificial intelligence, capable of self-replication), it would be feasible to construct a Dyson sphere, which would capture the energy of the sun and power a wave of intergalactic colonisation. The process could be initiated on a surprisingly short timescale.
But why would a civilisation want to expand its horizons to other galaxies? Dr Armstrong says: 'One reason for expansion could be that a sub-group wants to do it because it is being oppressed or it is ideologically committed to expansion. In that case you have the problem of the central civilisation, which may want to prevent this type of expansion. The best way of doing that get there first. Pre-emption is perhaps the best reason for expansion.'
Dr Sandberg adds: 'Say a race of slimy space aliens wants to turn the universe into parking lots or advertising space – other species might want to stop that. There could be lots of good reasons for any species to want to expand, even if they don't actually care about colonising or owning the universe.'
He concludes: 'Our key point is that if any civilisation anywhere in the past had wanted to expand, they would have been able to reach an enormous portion of the universe. That makes the Fermi question tougher – by a factor of billions. If intelligent life is rare, it needs to be much rarer than just one civilisation per galaxy. If advanced civilisations all refrain from colonising, this trend must be so strong that not a single one across billions of galaxies and billions of years chose to do it. And so on.
'We still don't know what the answer is, but we know it's more radical than previously expected.'
Images
Top: Future of Humanity Institute logo.
Middle: Dr Anders Sandberg (left) and Dr Stuart Armstrong.
Bottom: Hubble Deep Field image showing myriad galaxies dating back to the beginning of time. Image by Robert Williams and the Hubble Deep Field Team (STScI) and NASA.
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A science star is born
Jonathan Wood | 05 Aug 13 | 0 comments
Meeting Alison Woollard over a coffee is a delight. It's clear she is a story teller. She is engaging, enthusiastic, chatty, fun, easy to relate to, has lovely turns of phrase and illustrates everything with great tales and examples. I thoroughly enjoy the conversation and my time with her.
But those are all incidental skills of a presenter. She also has a great story to tell: Where we all come from.
And that's surely why she's been chosen as this year's Royal Institution Christmas lecturer.
The Christmas Lectures are an institution in themselves. Broadcast annually since 1966 from the Royal Institution's tight, high-sided lecture theatre, they are a fixture in the TV schedule as soon as the turkey and present opening have finished and a cornerstone of science education and outreach in this country.
Started by Michael Faraday in the first part of the 19th century, the lectures have always been loaded with showpiece demo after demo to illuminate the latest in scientific understanding in an accessible way for children (and their parents).
Dr Alison Woollard is Dean, Fellow and Tutor in Biochemistry at Hertford College, and a University Lecturer in the Department of Biochemistry, where her research looks at the nematode worm as a model system for understanding embryonic growth and development.
Her Christmas lectures on Life Fantastic will uncover the transformation through which a single cell becomes a complex organism. She will look at where we come from, what makes us, how we grow and how we age, but also how we might want to harness this knowledge and the questions it raises.
The lectures will bring in all sorts of subjects: covering some of the working of cells, developmental biology, how morphology changes over time, and evolution and the role of chance in shaping us as organisms.
So at Christmas time, when many people around the world will be celebrating a miracle birth, Alison will be explaining the amazing process by which a newly fertilised egg cell divides and grows. Or as she says: 'How cells in the growing embryo know what to do in the right place at the right time. How cells, all with the same DNA instructions, know to become liver cells, eye cells or toenail cells.
'It's all about interpreting those instructions,' she explains.
While it quickly becomes clear to me that she will make a tremendous presenter, when Alison first received an email inviting her to put herself forward for the Christmas lectures, her first reaction was to delete the email.
A few days later, she tells me, she retrieved the email from trash so she could at least leave it sitting there in her inbox. She then did nothing for a week. After a subsequent email chasing her, she did then draft a short proposal for the lectures and sent it off. She was surprised to get an audition. 'I'm still a novice,' she protests, though she admits that won't be the case come the New Year.
The Christmas lectures can draw anywhere between 1 and 4 million viewers, and is likely to be BBC Four's biggest show over the Christmas period.
'It's an enormous privilege,' says Alison. 'Other lecturers have had letters years later from scientists who say they were initially inspired by watching them.
'If my lectures are able to inspire any of the children in the lecture theatre or those at home, then job done!'
She suspects that the TV audience has a range of ages and interests, but doesn't believe that is a problem. 'The lectures need to be accessible to children and adults alike, and I don't see much difference. I think you can begin with basic ideas and go right up to the cutting edge, guiding people through and taking them with you.
'In my case, I have my 10 year old daughter at home to try stuff out on, and my mum at the other end of the spectrum.'
She is keen to use her set of lectures to go beyond explaining the pure science, and also explore some of the issues and ethical dilemmas it can raise.
'Part of my area of science includes new cell-based medicine and genome sequencing,' Alison says. 'These technical advances are important and raise some issues. There is a tremendous opportunity to improve human health, and a consensus will need to be reached on the issues.
'For example, where do we draw the line on screening for genetic abnormalities in embryos? If when born, we are presented with the complete sequence of our genome, we will need to understand risk to interpret information on what our genes may say about our future health.
'These need to be discussed, not just by scientists but by the public more widely. There is an absolute responsibility for scientists to take their science into society.'
Alison is also very clear on the importance of 'science where we don't know where it is going to lead; science that is blue skies, curiosity-driven, non-impact led'. She adds: 'Many medical advances have been purely serendipitous, arising unexpectedly from studying a biological problem.'
She points to the example of the important biological process known as 'apoptosis', or 'programmed cell death'. This is a normally well controlled and regulated process that is important in the development of an embryo, and is also a way in which cells in tissues that are stressed or damaged are shut down and broken apart.
Alison explains: 'The process was first identified in the nematode worm. The process's importance became clear when mutants lacking an active cell death pathway didn't develop properly and the embryos would die.
'Apoptosis is also important in cancer formation in humans. The inability of cells to die when they should, coupled with the uncontrolled proliferation of cells can drive the growth of a tumour.
'The molecules involved in apoptosis are very highly conserved. Those in the worm are similar to those in a human tumour. Studying simple, model organisms such as the worm can have an enormous impact on cancer medicine and biomedicine in general.'
Alison notes that she is only the fifth woman to do the Christmas lectures since they began in 1825. 'Which is kind of shocking,' she says.
She believes that there is much still to be done to solve the poor representation of women in many areas of science. It's not that male scientists are necessarily discriminatory or sexist, she says, the biggest problem is the career path. The need to keep producing results and journal papers, to work all hours in the lab, to keep going to conferences, all the things you need to run a successful research group – it is hard to marry that with having a family.
Alison took six months' maternity leave for each of her children, but much of that time she was still running her lab. 'Who else would know my research to direct it?'
She adds: 'Looking back, it was detrimental to my own experience to try and do all these things at the same time.'
Wanting a sneak preview of the lectures, I ask about the demos the Christmas lectures are known for.
'The demos are not worked up yet,' Alison says, to my disappointment. 'Unlike chemistry, where you can put two chemicals together and get a big explosion but there is perhaps more difficulty building a narrative, biology has extraordinarily profound ideas but you need to find the bangs.
'A lot of biological material needs microscopy to see what's going on,' Alison points out. 'We'll need good microscopy and good projection to grab the attention. We're thinking about great, high tech ways of doing this,' she reveals. 'One thing I can promise - we'll see life unfurl before our very eyes.
'We can also balance this with audience participation. Biology lends itself quite well to games, and we're thinking about that too,' she says.
As we continue to enjoy the summer, there are some things about Christmas I can't think about yet: Christmas shopping, the heavy eating and drinking. But watching Alison's Christmas lectures is one thing I'm already looking forward to.
(Full story) -
Winning image is all heart
Jonathan Wood | 26 Jul 13 | 0 comments
This picture shows the heart of a two-day-old zebrafish.
Its striking beauty has seen it win the Mending Broken Hearts prize in the British Heart Foundation's competition for outstanding images and videos from the research it funds.
The image was produced by Dr Jana Koth as part of her research at the MRC Weatherall Institute of Molecular Medicine at Oxford University.
Under the microscope, it is possible to see individual cells and the internal organization of the early heart as it grows and develops. The green cells are heart muscle cells, and the red and blue staining shows components that make up the muscle. The heart consists of two sections – the large, thin atrium (where blood flows in) and the smaller, thicker ventricle (where blood leaves the heart).
Remarkably, the hearts of zebrafish can repair themselves after damage, something which human hearts cannot do. The hope is that understanding this ability might in the future allow ways of prompting heart repair in people who have had heart attacks and develop heart failure, an area of research known as 'regenerative medicine'.
On winning the prize, Jana said: 'I'm stunned and delighted to receive this year's Mending Broken Hearts award. In the course of our regenerative medicine research we produce images like this all the time. They help us to uncover the secrets of the zebrafish. It's great to be able to take a step back and admire the beauty, as well as the biology, of this natural wonder.'
(Full story) -
When other planets get the blues
Pete Wilton | 11 Jul 13 | 0 comments
Why is the sky blue? It's a simple question but one with a surprisingly complex answer if the sky belongs to a planet outside our solar system.
'If you are on Earth looking up the sky looks blue because other wavelengths of light are scattered by molecules like oxygen and nitrogen in the atmosphere,' explains Tom Evans of Oxford University's Department of Physics. 'If you look at the Earth from space it appears (mostly) blue both because of this effect and because water in oceans and lakes absorb other wavelengths, only reflecting blue light back into space.'
So viewed through an astronomer's eyes colour is much more than a pretty effect: it's an invaluable source of information.
Now, for the first time, scientists have determined the colour of a planet outside our solar system (an 'exoplanet'). Because they are so distant, and so much smaller than stars, seeing exoplanets directly with current telescopes is normally impossible (most of what we know about them comes from indirect observations, for instance of nearby stars).
An international team, led by researchers from Oxford University and Exeter University, took advantage of a secondary eclipse, when a planet disappears behind its star. They used the Hubble Space Telescope to study the moment the exoplanet 'HD 189733b' passed behind its parent star so that they saw both the star's light and light reflected off the planet (its 'albedo') and then, once HD 189733b has disappeared, just the star's light on its own.
From the difference in brightness between these two observations they were able to infer HD 189733b's brightness and by examining the wavelength of light reflected off it they were able to determine that it would appear a deep cobalt blue to our eyes.
But HD 189733b, which is 63 light-years away, isn't blue because it is like Earth.
'It's very different from the planets in our solar system,' Tom Evans, first author of a report of the research in Astrophysical Journal Letters, tells me. 'Unlike Jupiter or Saturn this gas giant orbits very close to its star, so it's bombarded with massive amounts of radiation and its atmosphere can reach a temperature of over 1000 degrees Celsius. The planet is also tidally locked so that one side is permanently facing its star whilst the other side is in eternal shadow.'
Suzanne Aigrain of Oxford University's Department of Physics, also an author of the report, comments: 'Despite these differences the laws of physics are the same, and as every planet with an atmosphere in our solar system has clouds we can infer that HD 189733b has clouds. We suspect that these clouds are made of silicate particles, but we don't know how and where they are formed, and the fact that they could be moving at very high speed (with winds of up to 7000 kilometres per hour) makes observations very difficult.'
The researchers believe that a large part of HD 189733b's blue appearance is down to sodium atoms in its atmosphere, as sodium atoms absorb more light at red wavelengths. 'If it wasn't for sodium absorbing the redder wavelengths, the planet would probably be more of a white colour,' Tom explains.
'This planet has been studied well in the past, both by ourselves and other teams,' says Frédéric Pont of the University of Exeter, leader of the Hubble observing programme and an author of this new paper. 'But measuring its colour is a real first — we can actually imagine what this planet would look like if we were able to look at it directly.'
HD 189733b's system is one of the best studied of all exoplanet systems because its star is bright and close to its planets, making interactions easier to spot. 'It's one of the most favourable systems, there aren't many where we can do the same thing,' comments Suzanne. But its parent star does pose some problems; it's an orange dwarf (or 'K-dwarf'), around four-fifths the size of our Sun, that's very magnetically active so it regularly shoots out flares and star spots that can interfere with observations.
'One of the next questions to answer is just how much of the parent star's light HD189733b is absorbing, because the wavelengths we've measured only account for about 20 per cent of the starlight that falls upon the planet,' Tom adds.
Determining exactly how much energy is being fed into its climate system overall has important implications for the circulation and weather on the planet. To do this, the astronomers will need to extend the measurement at longer wavelengths. This will allow them to confirm that none of the red or near-infrared light can escape from the atmosphere, as they currently suspect.
Other members of the Oxford team, along with collaborators at Bern University, will now begin to feed all the data from the recent observations into a model of the planet's atmosphere. 'A lot of what we do draws on models produced using data from gas giants in our own solar system. These enable us to make some basic predictions, although we know that if we push these models to extremes some of these assumptions break down,' Suzanne tells me.
'We would also like to do similar measurements for other planets, to understand how pervasive clouds are in these 'hot Jupiter' planets,' she adds. 'Currently Hubble is the only telescope we can do this with, and it's not clear how many planets we can do it for (HD189733b is one of the most favourable targets). But in the future we may develop clever techniques that enable us to do some of this from the ground, though it's harder because the Earth's atmosphere gets in the way.'
The hope is that with new, more powerful instruments like the James Webb telescope and especially the proposed European space mission EChO we might be able to get an even better glimpse of the atmospheres (and colours) of this and other exoplanets.
(Full story)
About this blog
Gives you the inside track on science at Oxford University: the projects, the people and what's happening behind the scenes. Curated by Pete Wilton, science writer and OU Press Officer.
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