Sexy Farmers

5 03 2010

Burly farmer with dirty fingernails seeks like minded companion for long days toiling in the fields.  Enjoys pig breeding and whittling tools. GSOH.

Now then, girls, try to contain yourselves.  Does this conjure up an image of your perfect man? No?  Well, it may have been a different matter for eligible young maidens living in Britain 10,000 years ago.

At this time farming was a revolutionary new concept.  Until then, humans had been content with hunting for animals and gathering wild plants from the land around them.  Farmers first appeared in the Near East but soon began to spread west across Europe, eventually reaching the shores of Britain.  As they travelled, they seduced the local ladies, breeding with women who chose them over the local hunter gatherers.

The farmer

So, how on earth do scientists know this? Well, they have been taking a look at the DNA of people all over Europe, including here in Britain.  This has revealed hidden clues about the identity of our ancient ancestors.

To find out about the male members of the family they scrutinised the Y chromosome, as this can only be passed down from father to son.  Males have XY chromosomes, whereas females have XX.

It turns out that a particular type of Y chromosome very common in Europe originates from the Near East, where farming first started.  Scientists took DNA samples from more than 2,500 men, and could clearly see that this genetic type had spread across the continent, travelling to the west.  More than 60% of British men, and almost all Irish men, have this version of the Y chromosome.

The farmer’s wife

But what about our female ancestors? Well, this is where the story comes together.

Other scientists have been delving into something called mitochondrial DNA, or mt DNA. This is genetic information that we all have (male or female), but it is only passed down maternally – we all got our mt DNA from our mothers, and they from their mothers.

Studies fail to find evidence for waves of ladies flooding into Europe in the last 10,000 years. It would seem that women were less likely to be intrepid adventurers, preferring instead to stay in familiar surroundings.  Unlike the males who migrated from distant lands, bringing with them their farming skills and their Y chromosomes, the females bearing the next generation were local hunter gatherer women.

What were our ancient ancestors up to?

These discoveries shed light on who fancied whom as the agricultural revolution took hold between 5,000 and 10,000 years ago. As Patricia Balaresque, an author of the study, puts it:

“Maybe back then, it was just sexier to be a farmer.”

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References

Scrutiny of the boys was published in PLoS Biology:

Balaresque P, Bowden GR, Adams SM, Leung H-Y, King TE, et al. (2010) A Predominantly Neolithic Origin for European Paternal Lineages. PLoS Biol 8(1): e1000285

Scrutiny of the girls was part of the following study:

Richards M, Macaulay V, Hickey E, Vega E, Sykes B, et al. (2000) Tracing European founder lineages in the near eastern mtDNA pool. Am J Hum Genet 67: 1251–1276





Mimicry: sometimes it’s clever to be a copycat

14 02 2010

To take your mind off this frosty winter weather I want you to think back to the summer, when you were relaxing outside in a pub garden with a crisp, cool pint of beer. A yellow and black winged beastie buzzes its way over to your drink, and you jump up screaming and wildly flailing your arms (yes, you, with the pint). You then realise that it’s only a hoverfly… panic over. Have you ever wondered why a hoverfly, with its yellow and black stripes, looks so much like a bee or a wasp?

What is a mimic?

A mimic is a species that physically resembles another species. Mimicry is rife right across the tree of life. For example, several species of butterfly look remarkably similar to the pipevine swallowtail (below left), and in the aquatic world it is all the rage to look like a cleaner fish (below right). Plants even get in on the act, as insect-eating species produce glistening droplets that look just like nectar, or patterns on their leaves that resemble flowers. And cunning fungi are able to grow parts that look like the pollen grains and pollen tubes of their host plant.

Mimics and their models. Can you tell which species is copying which?

What’s it all about?

Mimics do not appear simply because it’s fun to look like a bee (although clearly it is); their copycat characteristics have come about for very important evolutionary reasons. Animals wear the warning stripes of other creatures that actually have something to back it up, such as a nasty sting or bite, or chemicals that are toxic or distasteful. This way they should get the same protection from predators, who have learnt to steer clear of the bright yellow stripes or bold coloured spots.

Of course, protection from predators is not the only reason to mimic. A fish called the sabertoothed blenny (above) copies the colour and body shape of a cleaner fish, and even dances like it. Other fish are happy to get up close to the cleaner fish as it picks off parasites from their scales and eats them (yum), so the disguise allows the blenny to get in close and take a bite out of its unsuspecting prey.

In the case of the fungi, faking it as a pollen grain gives them unrestricted access to the ovary of their chosen plant, providing an ideal route of infection. And the plants mimics? They use their pretend nectar or flowers to lure in their insect prey.

This phenomenon is called Batesian mimicry. It is named after the English naturalist Henry Walter Bates (right), who came up with his explanation for copycats after observing butterflies in the rainforests of Brazil.

When all copycats are equal.

Brazil is clearly the place to be if you want to have a biological theory named after you. Another adventurer who spent a lot of time there was German biologist Johann Friedrich Theodor Müller (right). He discovered a different type of mimicry called… wait for it… Müllerian mimicry.

He set out to answer a big question: how come there are plenty of species that resemble each other and have distinctive markings, yet which do have the dangerous sting or the crafty lifestyle to back it up? For example, why is yellow and black so popular with poisonous stuff?

Let’s say you start out as a big bunch of species, who all use toxic poison or venom as your defence against predators. It makes sense that you would all evolve the same visible markings to warn of this. If you all use the same (or a similar) system, predators will learn to avoid it whatever type of creature you are, and those of you who match that critical signal more closely are more likely to survive. You survive, you have offspring, and so the cycle continues; this is natural selection at its best.

Back to the humble hoverfly.

So, next summer when your picnic is disturbed by a hoverfly, before you dismiss it as a harmless insect, perhaps you could think of all the evolution it had to go through to get its stripes. And give it a pat on the back for doing such a good impression.





How Super are Superbugs?

2 02 2010

Unless you have been locked in a darkened room for the past decade you’re sure to have heard of the dreaded superbug MRSA.   But what is it, what can it do to us, and is it really very super?

First things first, what is MRSA?  Those four ominous initials stand for Methicillin Resistant Staphylococcus Aureus.  It is a type of bacterium, with the scientific name Staphylococcus aureus, that causes a whole host of life threatening diseases but can’t be killed off by the antibiotic methicillin.  Or, it has to be said, by pretty much any of the antibiotics we throw at it.

And what can it do to us if we catch it?  You may simply have a superficial infection of the skin or the soft tissue beneath it, perhaps a boil or impetigo, and make a full recovery.  However, in some cases bacteria spread into your bloodstream and to other organs in the body.

The list of ensuing diseases does not make for very pleasant reading:

  • Septicemia – blood poisoning
  • Endocarditis – infection of the heart valves
  • Necrotising pneumonia – infection of lung tissue
  • Toxic Shock Syndrome – bacteria can release a potent toxin into the body and cause fever, sickness and organ failure

Tragically, many people will know a friend or relative who caught MRSA during a hospital stay as the bug infects around 2% of all patients.  But where does it come from in the first place?  And how has it become an antibiotic resistant superbug?

A body full of bacteria

It may not be a very nice thought (my apologies to anyone reading whilst eating their breakfast), but the human body is covered inside and out with millions of microscopic bugs.  This includes things like bacteria, viruses and fungi.  Amazingly, there are actually 10 times more bacterial cells in your body than human cells.  They live on your skin, up your nose, in your mouth, throughout your gut, and most of the time they are completely harmless.  In fact, we could not survive without them.

Among these millions of germs is one particular type of bacteria called – you guessed it – Staphylococcus aureus.  It makes its home on the skin and inside the noses of 20% of people, but most of them will never know.  In a few people, however, the bacteria find a way to get inside the body.  This might be via a cut such as a surgical wound, or where a medical device is inserted – perhaps a drip or catheter.  When this happens it is bad news; devastating news if there are no antibiotics around to combat the infection.

DNA: the key to antibiotic resistance

One of the amazing things about bacteria is how they get their DNA.  Whereas we, like other animals, inherit all of our genes from our parents, bacteria can also pass useful segments of DNA from one to another, even to bugs of a different species.

Scientists discovered one such segment, called a cassette, containing several very important genes that protect the bug from antibiotics.  If you are a bacterium and a neighbour sends over the cassette, you can incorporate it into your genome and – voila – you are resistant.  You are now a superbug.

How super is MRSA?

Humans and bacteria seem to be locked in an arms race. As fast as we can develop new treatments or prevention measures, the bugs find a way to get round them and keep infecting us.  But as long as scientists keep up the research into new treatments, and continue to unravel the story of how the bugs are doing such a good job of making us ill, there is certainly hope.  MRSA may be super at getting round our defences, but we are fighting back with the product of our human brain cells.





There’s so much science out there!

11 12 2009

Last week I went a bit seminar crazy, attending five talks in two days. They were all great, and so I urge everyone to hunt out public talks where they live. Who knows what you’ll find, and at least it makes a change to a night in flicking through TV channels.

My brain is now full of facts about weird bedbug sex, the dangers of eating flying foxes, homicidal genes, magical lakes that give warriors supreme powers, and even tactics for avoiding stress at the self-service checkout in Tesco. I hope to give you a taster of some of these talks, starting with the EUSci seminars in Edinburgh…

EUSci seminars – pizza, beer and science

On Thursday night I went along to the EUSci seminar session, in its new home of the Meadow bar in Edinburgh (thanks to Ed Duca for the photos). These seminars are informal and light hearted, covering a variety of subjects, so you don’t need to know anything about the topic. Just go along and you’re sure to find out something new. They even provide free pizza and a drink from the bar, a definite plus point in my book. There will be a break over Christmas but February 2010 will bring an eager new bunch of speakers, so give it a go if you’re in Edinburgh.

Selfish Genes – just how selfish can they be?

Arvid Ågren was the first of two speakers with his talk A War Within Us, about selfish genes. He gave a great overview of the subject, with fascinating facts about genes that are so efficient at making more copies of themselves that they harm the body they’re in, and other genes in the genome.

Arvid illustrated his explanation of complicated genetic theory with his own ideas about how he might go to battle if he were an army general. Apparently, the following three options are your best bet in a genetic war zone:

1. Kill the others
2. Bring in your daddy
3. Run!

As it turns out, there are a number of genes that employ extreme strategies, including the intriguing jumping genes (transposons) that jump around the chromosome making extra copies of themselves. However, Arvid warned against attaching human emotions to the idea of a selfish gene; there is no such thing as a consciously selfish gene, just as there is no such thing as a jealous molecule or an abstract elephant. The way they behave is simply a result of their strategy for survival of the fittest.

The talk prompted great discussion around the subject of selfish genes, and what makes some more selfish than others. And, finally, I’m sure any dads out there will be fans of Arvid’s advice: listen to your father, even if it hurts your mother.

Computer Anxiety- Does it really exist?

Benjamin Cowan provided the other half of the evening’s entertainment.  He had something to say about the concept of people being scared of computers. I think it is safe to assume that readers of this blog will be pretty computer savvy. But we all know somebody who is not quite so happy, who shudders at the thought of making contact via email or using the internet to do their Christmas shopping.

It is generally accepted that a good way to reduce people’s anxiety is to make sure that the interface is user-friendly. People feel happier if they have a positive experience using a computer, whether it is their PC at work, their home computer, or even their mobile phone or a self-service checkout at the supermarket.

But Benjamin’s bugbear about this area is the very idea that computer anxiety exists. He thinks that, by labelling it as a condition or a concept, we distinguish it from any other form of anxiety. Surely, most people are anxious about stepping out of their comfort zone and trying new things, whether it is starting a new job, meeting the parents of the latest love of their life, or eating a miscellaneous fried animal whilst back packing in Asia. If these new things seem complicated and involve the use of expensive equipment, as in the world of computers, it’s perhaps not surprising that people are anxious.

More seminars to come…

Come back for part 2 (and maybe even part 3, if you’re really lucky!) to hear about bedbug sex, flying foxes, and discovering medicines on remote pacific islands.





Science & The Media

8 11 2009

The last couple of weeks seem to have turned into a media fortnight, providing me with a tentative insight into science and the media. I’ve also heard from several talented experts actively involved in public engagement and science communication. So I thought I might get blogging.

This week I’ve been zipping up and down the country attending two workshops. The first was a course run by the BBSRC, the research council who fund my PhD, aimed at equipping scientists with the skills needed when we interact with the media. The second was a workshop run by Sense About Science, discussing a while host of issues that early career researchers come across when standing up for science.

Photo: Norrie RussellLast week (and yes, this is a shameless plug of my very first first-author paper!), myself and my supervisor Ross Fitzgerald were lucky enough to get some media interest in our scientific discoveries. Our paper came out in Proceedings of The National Academy of Sciences, and was picked up by a few newspaper and radio journalists. I was also delighted to find that Ed Yong wrote a piece on his Not Exactly Rocket Science blog. My Mum even read his blog entry and now finally understands what I’ve been doing for the past 3 years – proof of his skills in Science Communication, I’m sure you’ll agree.

Photo credit: Norrie Russell

I thought I might put together a list of top tips, summing up the recurring themes that have emerged over the last two weeks.

  • Find your hook. Whether you’re talking about your research to a journalist or communicating science to a lay audience, package it as a complete story, starting with an engaging sentence or two summarising the results.
  • Remember that journalists are under completely different pressures and schedules to those in the world of research. They think in hours and days, not weeks and months.
  • Pay attention to your Press Release. This should contain everything that media folk need to know. Make the most of your Press Office as they have exactly the skills needed to get this right.
  • Be proactive. Approach your Press Office if you have an interesting paper coming out. Alternatively, offer journalists your services as an expert happy to comment on developments in your field. If you are passionate about a scientific issue, get out there and take part in the debate

Useful links

Science & The Media:

Sense About Science

BBSRC Media, News & Events

The Science Media Centre

The British Science Assocation – Why work with the media?

The Royal Society – Scientists & The Media

University of Edinburgh Press Office

To find out more about my research:

News on the University of Edinburgh Website

BBC News

The Times

Ed Yong ‘Not Exactly Rocket Science’





The Great Vaccine Debate

20 10 2009

Childhood vaccination is a hot topic constantly cropping up in our newspapers and on our television screens. Interestingly, although I don’t work in vaccine research, I’ve noticed that the subject is often brought up by fellow scientists – perhaps health scares and misinformation surrounding vaccine safety represent the big struggle between science and some branches of the media. The issue has become the controversy of the moment, and arguably an easy target for sensationalist journalism.

Every year thousands of parents up and down the country have to make a decision about whether to vaccinate their child against a myriad of infectious diseases. In the UK we’re not forced into this, unlike many other places across the globe. In the USA and many European countries, children are not allowed to start school until they’ve had their shots, and in Belgium failure to vaccinate your child could even land you in prison.

We should be proud of our attitude towards individual choice, and as long as enough people decide to go ahead we don’t have a problem. But if scare stories continue and parents become increasingly hesitant, we could get dangerously close to falling below that important watershed where major disease epidemics become a reality. I am not suggesting that we introduce compulsory vaccination, nor that parents are not entitled to make an informed decision about the health of their child. Instead, I propose that the scientific community should sit up and make itself heard; we must ensure that the debate is fair and balanced, and that information reaching parents truly reflects the risks.

Advertising campaigns for vaccination campaigns past and present

Advertising for vaccination campaigns past and present

Vaccination in the news

At the end of September we were inundated with media reports of the tragic news that a 14 year old girl in Coventry had died shortly after receiving the cervical cancer vaccine Cervarix. The day after the news broke I was on the bus to work and read a report in The Metro over the shoulder of another passenger. I was surprised to read that apparently “the death has raised questions about the safety of the vaccine, the secrecy surrounding clinical trials and why Britain has chosen a different type to most other countries”. In just one sentence – bam – the journalist had put serious doubt into the mind of every parent reading. It seemed to me ridiculous to even hint at such serious claims before post-mortem investigations had been performed.

Tabloid newspapers are known for their sensational headlines, but are they based out sounds scientific backing?

Tabloid newspapers are known for their sensational headlines, but are they based out sound scientific backing?

It was sadly discovered that the school pupil had died as a result of an undiagnosed tumour, a fact that was fairly widely reported. But the notion of conspiracy by the government and pharmaceutical industry had once again been brought to public attention. These reports have added to a growing list of apparent concerns about vaccine safety, even if only subconsciously.

At the top of this list is the MMR vaccine, following the 1998 paper published by Dr Andrew Wakefield suggesting a link between this jab and autism. The case made in the paper was weak even at the time of publication and ten of the paper’s 13 authors now refute the original findings. Several subsequent studies, each more extensive and rigorous than Wakefield’s, have completely failed to reach the same conclusions. (For an excellent review of this issue, follow the links provided by Sense About Science on their website www.senseaboutscience.org.uk/index.php/site/project/143/). But none of this seems to have made it to the front page of a national newspaper, and much of the public mistakenly believe there is an ongoing debate with no clear conclusions.

All part of a greater problem?

Is this attitude part of a much bigger problem? Have the Great British public stopped trusting scientists? People seem to question the motives not only of the researchers, but also of the policy makers who decide on the best way to implement their findings.

I have been fortunate enough to work with a number of respected scientists over the last few years, many of whom have dedicated their lives to studying the bugs and diseases that cause illness and death around the world. I’m sorry to disappoint any wannabe tabloid journalists looking for a scoop, but not one of them fits the stereotype frequently portrayed in media reports. The world of medical research is not populated by fame-hungry or shady characters, willing to make up results or endanger lives by ignoring side affects in medical trials, just to build up their bank balance or have their 5 minutes of fame.

So what is the answer to this growing problem? Can we halt the gradual erosion of public confidence in scientific research, and particularly in vaccination? Perhaps the answer is to get out there and improve public knowledge about the principles of scientific rigour, peer review, and medical trials. As scientists we should not sit tight in our academic bubble, perhaps knowing right from wrong (or, at least, having an opinion based on sound scientific reasoning) but failing to share this with the people out there in the real world.

Sense About Science - promoting good science and evidence for the public

Sense about Science are a fine example of a group striving to do just that, debunking myths about everything from food additives and detox diets to nuclear energy. We merry band of geeks in the world of research should jump on the bandwagon, joining them or at least following their example. Maybe then we can change the image portrayed in the popular press, rebuild public confidence in science and help people to realise that scientific discoveries are changing lives for the better.





Talking Evolution at The British Science Festival

18 10 2009

It’s Thursday night and I’m standing in a student bar in Guildford.  I have just witnessed a man on stage have his chest and nose hair pulled out with tweezers, allegedly illustrating a point about pain receptors. Next the author Bill Bryson takes to the stage to discuss his popular science book ‘a short history of nearly everything’. Enjoying a drink at the table next to me is the moustachioed scientist Professor Robert Winston, who intercepts the roving microphone to ask Bill his opinion on school science lessons. “Not your average Thursday night”, you might say.  Unless, of course, you are at the British Science Festival, an annual gathering where over 350 of the UK’s top scientists and speakers meet to discuss the latest scientific developments with more than 50,000 members of the public.

The British Science Association (formerly known as the BA) has been holding its annual festival for no less than 178 years.  The festival is one of many ways the association achieves its aim to ‘connect science with people’, and has provided a platform for numerous scientific announcements from the first use of the term ‘dinosaur’ in 1841, to the demonstration of wireless transmission in 1894.  Stephen Hawking gave his first public talk at the 1982 festival in Liverpool.  So how did I, a PhD student from Edinburgh, get involved with the 2009 event? Back in March an email landed in my inbox about a competition called Perspectives.  The ‘poster session with a difference’ invited researchers to explore the social and ethical implications of their work and gain valuable experience in public engagement.

Perspectives at the British Science Festival

Perspectives at the British Science Festival

I submitted a piece of writing designed to enlighten a non-specialist audience about the fascinating world of chickens and bacteria, and was lucky enough to be shortlisted as a finalist.  A few months later, along with 35 other PhD students and post-doctoral researchers from across the UK, I travelled down to the Dana Centre in London for training in science communication and poster design.  Armed with new-found skills and enthusiasm for the task in hand, we set off back to our universities and institutes to work on our posters, which were unveiled when we arrived in Guildford for the festival in September.

Visitors to our hall of posters ranged from scientists and engineers to journalists and politicians, including the science minister Lord Drayson.  Several families and school groups also passed through, and I was approached by an inquisitive young student with a dislike for chicken burgers.  She was keen to persuade her mum to stop cooking them for her dinner, and thought that a bit of scientific backing would help her on this mission.

Enlightening the judges about the wonderful world of chickens and bacteria

Enlightening the judges about the wonderful world of chickens and bacteria

Away from poster duties, we also had time to attend some of the talks and events taking place.  An interesting session called ‘pest wars’ discussed the evolutionary arms race raging in our fields, between insects and the pesticides we’re using to combat them.  The scientists behind the research later held a press conference, as did several of the most prominent speakers at the festival, covering hot topics such as global food shortages and pandemic flu management.  This allowed journalists to quiz the scientists on issues of interest to their readers, and were clearly fruitful if the expanse of newspaper clippings pinned to boards in the media zone were anything to go by.

Evening events also provided science-related entertainment.  Robert Winston no doubt gained a few fans when he stated that “PhD students are the backbone of scientific research”, in a chat show style interview conducted by eminent physicist Jim Al-Khalili. The Chancellors Bar at the heart of Surrey University campus played host to a more light-hearted event called ‘X-change’, a daily round up of festival highlights compered by enthusiastic science writer and BBC broadcaster Sue Nelson.  In addition to the aforementioned nose hair plucking, the audience learned about the dangers of licking metal poles in the Antarctic, how to build a racing car using chocolate and carrots, and the anatomical accuracy (or otherwise) of drug smuggling capacity detailed in the books of crime writer Stuart MacBride.

Professor Robert Winston - The Man Behind the Moustache

Professor Robert Winston - The Man Behind the Moustache

Returning to the competition, our third day at the festival was spent talking to a panel of expert judges from the world of science communication.  They posed plenty of challenging but very interesting questions, prompting in-depth discussion all round.  Gemma Webster from the University of Dundee was the deserving winner with her poster ‘What’s in a label?’ about her research into dementia and the elderly.  I was delighted to be one of five runners up, and left Guildford at the end of the week glad to have taken part.  Perspectives provided an opportunity to talk about my work to a completely different audience and to meet a whole host of interesting people, all enthusiastic about their research and keen to spread the word about the wonders of science.

The 2010 festival is being held in Birmingham at Aston University, and will no doubt have plenty of interesting speakers and exciting events to get involved with.  My one piece of advice – if you find yourself in the front row when a biologist asks for a ‘particularly hairy volunteer’ for his experiment on pain receptors, it may be wise to keep quiet.

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This is an early version of a piece that appeared in the 5th edition of the EUSci magazine. Feel free to take a look at the finished article, and the rest of the magazine at www.eusci.org

Also, check out the following links to find out more about the festival and the competition:

Perspectives competition – http://www.britishscienceassociation.org/web/ScienceinSociety/Perspectives/

British Science Festival – www.britishsciencefestival.org

British Science Association – www.britishscienceassociation.org

Sue Nelson’s blog from the festival –  http://news.bbc.co.uk/1/hi/sci/tech/8240096.stm

British Science Festival blog – http://britishsciencefestival.wordpress.com/