London bread shortage in the 1970s. Yeast genetics are at the vanguard of synthetic biology. Photo: Getty
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Welcome to the age of synthetic biology – it’s all about yeast

We don’t need evolution any more – we've outsourced the processes to ourselves.

Evolution’s retirement plan has been 3.6 billion years in the making. With the appearance of the modern human being, we now have an organism that can take over from natural processes and engineer biology in entirely new ways. Welcome to the age of synthetic biology.

The basic idea is that we take an organism – a bacterium, say – and re-engineer its genome so that it does something different. You might, for instance, make it ingest carbon dioxide from the atmosphere, process it and excrete crude oil.

That project is still under construction, but others, such as using synthesised DNA for data storage, have already been achieved. As evolution has proved, DNA is an extraordinarily stable medium that can preserve information for millions of years. In 2012, the Harvard geneticist George Church proved its potential by taking a book he had written, encoding it in a synthesised strand of DNA, and then making DNA sequencing machines read it back to him.

When we first started achieving such things it was costly and time-consuming and demanded extraordinary resources, such as those available to the millionaire biologist Craig Venter. Venter’s team spent most of the past two decades and tens of millions of dollars creating the first artificial organism, nicknamed “Synthia”. Using computer programs and robots that process the necessary chemicals, the team rebuilt the genome of the bacterium Mycoplasma mycoides from scratch. They also inserted a few watermarks and puzzles into the DNA sequence, partly as an identifying measure for safety’s sake, but mostly as a publicity stunt.

What they didn’t do was redesign the genome to do anything interesting. When the synthetic genome was inserted into an eviscerated bacterial cell, the new organism behaved exactly the same as its natural counterpart. Nevertheless, that Synthia, as Venter put it at the press conference to announce the research in 2010, was “the first self-replicating species we’ve had on the planet whose parent is a computer” made it a standout achievement.

Today, however, we have entered another era in synthetic biology and Venter faces stiff competition. The Steve Jobs to Venter’s Bill Gates is Jef Boeke, who researches yeast genetics at New York University.

Boeke wanted to redesign the yeast genome so that he could strip out various parts to see what they did. Because it took a private company a year to complete just a small part of the task, at a cost of $50,000, he realised he should go open-source. By teaching an undergraduate course on how to build a genome and teaming up with institutions all over the world, he has assembled a skilled workforce that, tinkering together, has made a synthetic chromosome for baker’s yeast.

The chromosome works just as well as the natural one and is the first step towards an entirely synthetic yeast. What’s more, the synthetic chromosome already does unusual things. The team can watch it shuffle its genes around, or even delete some. That way, they can identify how evolution over-engineered the organism, and also what variations might make it more useful or interesting.

One of the research partners was Imperial College London, where an international meeting on the future of synthetic biology took place this month. The science minister David Willetts gave the main speech, thanking evolution for its contributions and presenting it with a gold watch.

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 09 April 2014 issue of the New Statesman, Anxiety nation

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.