Podcast: The oldest drawing and the energy of data

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Host: Adam Levy

Welcome back to the Nature Podcast. This week, we bring you news of the oldest ever hashtag.

Host: Shamini Bundell

Plus, the hidden energy costs of all your data. I’m Shamini Bundell.

Host: Adam Levy

And I’m Adam Levy.

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Interviewer: Adam Levy

About 300 kilometres east of Cape Town, on the coast of South Africa, is Blombos Cave. It’s a pretty small cave only some 55 square metres in area, but this tiny cave has hidden huge secrets about the ancient humans that visited it.

Interviewee: Christopher Henshilwood

Inside the cave, we have a perfect record of the activities that were carried out by those people during that time period from 70,000 to 100,000 years ago.

Interviewer: Adam Levy

This is archaeologist Christopher Henshilwood. Christopher’s been excavating Blombos Cave since the 90s, peeling back the layers of the past.

Interviewee: Christopher Henshilwood

So, it’s like layers of a cake. As people came in, they did a whole lot of things and they left and the next people came in. It’s extremely rare. You can really count the number of sites like that on the fingers on one hand.

Interviewer: Adam Levy

And from this rare site, Christopher has uncovered remarkable finds: engravings on ochre dating to 75,000 years ago, beads that would have been worn as jewellery.

Interviewee: Christopher Henshilwood

And then finally in 2011, we published this toolkit from the 100,000-year-old levels which was a real breakthrough because here you had perfectly preserved two abalone shells filled with ochre-rich paint, even with a little paintbrush still sitting on the edge of the shell. And all of a sudden, you had a whole slew of pieces of evidence that strongly pointed to Homo sapiens — our ancestors in Africa — being, behaving really modern, long before they left Africa.

Interviewer: Adam Levy

This slew of evidence challenges ideas that Homo sapiens’ creativity had originated in Europe. Now, in Nature this week, Christopher is publishing yet another example of the creativity of the ancient people who visited Blombos Cave: an ancient fragment of stone with a red pattern on it that looks strangely familiar to a millennial like myself.

Interviewee: Christopher Henshilwood

You’ve seen a hashtag. You’ve seen three lines which are made in one direction diagonally and then six lines made in the other direction diagonally.

Interviewer: Adam Levy

Hashtag or not, the red pattern is quite clear. But Silvia Bello, an archaeologist who didn’t work on this study, acknowledges that this find might not immediately jump out at the untrained eye.

Interviewer: Silvia Bello

It might not look too exciting possibly for someone who’s not an archaeologist as it is a small flake. However, it has these very interesting lines and it seems completely different from other finds at the site.

Interviewer: Adam Levy

To Christopher, this find from Blombos Cave was tantalising.

Interviewee: Christopher Henshilwood

We were certainly excited when it was reported that the piece had been found and it looked, you know, to our eyes as archaeologists very convincing, but that was not good enough.

Interviewer: Adam Levy

So, Christopher and his collaborators set out to test what exactly it was they had found. The red cross-hatching, it turned out, was ochre marked on the stone. But marked how? To find out, the team used a variety of approaches to try to recreate similar ochre marks.

Interviewee: Christopher Henshilwood

We were using a small wooden stick. We painted that mixture onto a silcrete flake that looked very similar to the one that we’d recovered from the site. We then also made crayons of various thicknesses and we then drew lines on the experimental pieces. It was absolutely clear at the end of the study that what we had was a drawing on a piece of ochre 73,000 years old.

Interviewer: Adam Levy

And this age is what makes this find so special. While there are other, older examples of human creativity from Homo sapiens and our relatives, these are typically carvings. But this is the oldest drawing, and by some margin. The next known Homo sapien examples are in Europe and Asia from about 40,000 years ago, and although those cave paintings are more figurative, including hand stencils and depictions of animals, Blombos Cave’s abstract hashtag predates them by some 30,000 years. If you’re struggling to get your head around the scale of these timeframes, well, rest assured, you’re not the only one.

Interviewee: Christopher Henshilwood

We’re talking here about 6,000 generations ago. Many people can’t even imagine what 100,000 years could look like in terms of time because if you look at the pyramids, they’re just a couple of thousand years old and that seems to be extremely old.

Interviewer: Adam Levy

And with its extreme age, this drawing adds to the wealth of expressions of human creativity that have emerged from Blombos Cave.

Interviewee: Christopher Henshilwood

We’ve never found a drawing before and that drawing was thought the fifth leg of the table because that put into place that those people were capable, in terms of their behaviour, to produce a whole suite of artistic behaviours.

Interviewer: Adam Levy

This artistry, though, is abstract. Unlike the figurative representations that appeared later, these hashed lines are more mysterious. We’re inevitably limited in our understanding of both their intent and their significance. But Christopher and Silvia point out that its abstract nature shouldn’t suggest that it’s without meaning.

Interviewee: Christopher Henshilwood

So, we have to be careful because on the one hand, we absolutely know that we have not found any figurative drawings from before 40,000 years ago, but that doesn’t mean that these early abstract paintings and drawings didn’t carry meaning. Clearly, they did.

Interviewer: Silvia Bello

Even nowadays we sometimes don’t understand the reasoning behind an artist producing a piece of art so why would we expect to know what all these abstract signs mean?

Interviewer: Adam Levy

The artwork itself may be abstract. But for Silvia, discoveries like these help make our ancient Homo sapiens’ relatives just a little bit more tangible.

Interviewer: Silvia Bello

Here we are looking at something that doesn’t seem to be particularly useful for the specific purpose of surviving, for hunting of the bare necessities. We always think of art as something quite modern, but this is actually very old. But the fact that they were taking time to do something that it doesn’t seem to be immediately related to a necessity, I think it is fascinating. It makes them closer to us.

Interviewer: Adam Levy

That was Silvia Bello who’s based at the Natural History Museum in London. You also heard from Christopher Henshilwood who’s based at the University of Bergen in Norway and the University of Witwatersrand in South Africa. You can read Christopher's paper at nature.com where you’ll also find an Editorial and a news piece on the study.

Host: Shamini Bundell

Stay tuned for the News Chat, where we’ll be hearing about the researchers trying to get to grips with the health effects of wildfires. Right now though, it’s the Research Highlights, bought to you by Anna Nagle.

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Host: Anna Nagle

A small species of hammerhead shark is rather undermining their bloodthirsty reputation by becoming flexitarians. Bonnethead sharks have been seen supplementing their meaty prey with seagrass from the underwater meadows where they live, but scientists didn’t know if they actually digested the greens. Researchers fed a group of captive bonnetheads seagrass spiked with carbon-13. After a few weeks on the diet, they found high levels of carbon-13 in the sharks’ blood, which must have come from the seagrass that they’d eaten. Couple that with an enzyme found in the sharks’ gut that can break down cellulose, and scientists can now declare the bonnethead to be the first known omnivorous shark. Check out what’s on the menu over at the Proceedings of the Royal Society B.

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Flu season is looming, and drug-resistance is on the rise. But never fear, we might be close to adding a new weapon to our anti-flu arsenal. The new compound Baloxavir works by inhibiting the flu virus’ ability to replicate itself. In large-scale trials, patients’ viral load dropped steeply after just one day on the treatment, much more quickly than for those taking a standard antiviral medication. And although the patients’ symptoms didn’t improve any quicker, the researchers say that the compound could be a useful alternative for people that don’t respond to other treatments. Read more in the New England Journal of Medicine.

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Interviewer: Shamini Bundell

Pretty much everything we do in our lives has some impact on the planet and on climate change. Driving to work burns petrol, boiling a kettle uses electricity, eating beef adds methane to the atmosphere. But of course, it’s not just individuals who have an impact. Large multinational companies also have their carbon footprints. While oil and transport companies may be among the obvious players, the very biggest companies these days don’t trade in material goods but in data. Companies like Facebook and Google — how are they impacting the environment?

Interviewer: Nicola Jones

These companies, they don’t look like environmental problems, right? They’re not spewing black smoke or grinding greasy cogs or producing pollution, but they are using a lot of energy to make them work.

Interviewer: Shamini Bundell

This is reporter Nicola Jones who’s written a Feature in this week’s Nature about the amount of energy used by these companies, in particular the energy used by data centres. I gave her a call to find out what the problem is.

Interviewer: Nicola Jones

So, data centres are these huge buildings the size of aircraft carriers, and they need electricity to make them run. It’s just stacks and stacks and stacks of tens of thousands of servers. So, every time you’re uploading Facebook pictures or every time you’re streaming a movie on Netflix, you’re using energy and we’re a very data-hungry society. We’re using more and more and more data and all of that is using more and more energy.

Interviewer: Shamini Bundell

And does it really use that much energy because when I think about the things I’m doing around my house with all my plastic wrapping from the supermarket or cooking with gas on the stove, I really don’t think of browsing the internet as being something that’s going to take up a lot of energy.

Interviewer: Nicola Jones

No, exactly, nobody really does. Right now, we use around 200 terawatt hours for all the data centres on the planet, and that is about 1% of the current electricity demand globally. So, whether you think that’s a lot or a little depends on your perspective. So, you could say that that’s more than the electricity consumption of some countries. On the other hand, that’s half the electricity that’s used for things like transport.

Interviewer: Shamini Bundell

And is the problem here, you know, increased energy use over the planet which is basically, comes back to climate change? We’re going to be getting a lot of that energy from fossil fuels and thus, our energy use is contributing to climate change.

Interviewer: Nicola Jones

Yes. So, the planet’s electricity use is just kind of skyrocketing. So, it would be great if we could be really efficient about how we use our electricity and also that we make our electricity from clean sources.

Interviewer: Shamini Bundell

So, that would be great for the planet, but are the big companies who own all these servers actually invested in reducing their energy use?

Interviewer: Nicola Jones

They are. So, reducing your energy use is not only great for the planet, it’s good for your budget, right? So, one thing that we’ve seen happen over the last kind of decade or so, is that Facebook for example in 2011, built its own data centre, and these data centres, they make their own servers from scratch, specifically designed to do what they want to do and they cut out all the bells and whistles, so that they’re as efficient as possible. And they also spent a lot of time thinking about things like how the building is run. So, for example, computers need to be cooled. You probably know that from your own computer, your own laptop — there’s a fan running to cool it. So, data centres spent a lot of time and energy working out more efficient ways to cool their buildings. And at the core, the efficiency of a data centre depends on the efficiency of the actual computer chips that you’re using. You know, our computer chips are shrinking and getting more efficient and better at doing what they’re doing but there are limits to that, and eventually, we’re going to have to shift to some kind of totally different kind of computing in order to get more efficiency out of things, like maybe quantum computing.

Interviewer: Shamini Bundell

What do experts think we’re going to see going forward with changing demand for energy and demand for data and technological changes?

Interviewer: Nicola Jones

It depends who you talk to, but some of the more kind of alarming predictions show that maybe we’re going to be using 20% of global electricity demand by 2030 for all of our information communication technology industry.

Interviewer: Shamini Bundell

And there were some people who you had spoken to in the Feature who were quite concerned about this possibility, and then others who were more sceptical of those predictions. I spoke to one of your sources, Jonathan Koomey, a researcher on data electricity use. This was his take.

Interviewee: Jonathan Koomey

There are those who think that electricity demand in data centres has been growing and will continue to grow very rapidly, and from 2000–2005 we actually did see a doubling, in the United States and in the world, of electricity use in data centres. But the interesting historical fact is that since about the time of the global financial crisis, there’s been almost no growth in electricity use by data centres. So even though we’ve had a very rapid increase in the use of computing, we’ve been able to improve efficiency so rapidly that we’ve kept data centre electricity use roughly flat in the last 8 or 9 years. So, we expect that the efficiencies that come from using cloud computing will offset the growth in demand for the service and that that will continue for the next 3–5 years.

Interviewer: Shamini Bundell

That was Jonathan Koomey there, and so Nicola, back to you. How optimistic are other researchers about this idea, that we can keep improving efficiency and improving technology and keep the actual electricity use flat?

Interviewer: Nicola Jones

People definitely have differing views on whether technology will step in to save us. So historically, if you look at the last 5 years, yes, things like shuttering small data centres and moving their business over to these super-efficient, large data centres is really helping us to save a lot of energy. But that can’t go on forever, so there are certain efficiency gains that we’re taking advantage of right now which are probably going to run out within a decade or maybe two and then who knows that will happen after that.

Interviewer: Shamini Bundell

And then when I asked Jonathan about the next decade or two, he wasn’t prepared to speculate beyond 5 years into the future. And actually, there is a lot of scepticism, isn’t there, about sort of long-term predictions.

Interviewer: Nicola Jones

Yes, trying to forecast future data use is really hard because we don’t know exactly what people are going to be using their computers for. So, for example, if artificial intelligence becomes a really common system that people use for a lot of things, that could really boost our computing power. There’s also a point of view that if you make something more efficient, you just use it more. So, for example, in the old days, it was really clunky and hard to stream a movie on your computer. Now, it’s so easy that we just use it more. So, there’s an argument that even if you make things more efficient, all you’re going to do is increase usage to offset those efficiencies, so it’s really hard to predict what’s going to happen in the future.

Interviewer: Shamini Bundell

That was reporter Nicola Jones and you also heard from Jonathan Koomey. Read more in Nicola’s full Feature at nature.com/news.

Interviewer: Adam Levy

Time now for the News Chat, and Nature’s Bureau Chief of the Americas has found her way across the Atlantic and into our London studios. Lauren Morello, welcome.

Interviewee: Lauren Morello

Hi Adam.

Interviewer: Adam Levy

Now, first story. We are turning back to the Americas. There have been huge wildfires engulfing California. Well firstly, how big are we talking with these fires?

Interviewee: Lauren Morello

Wildfires in California have burned in areas so large this year that it set a new annual record and they’ve destroyed an area that’s larger than London.

Interviewer: Adam Levy

So, with these huge fires, researchers are trying to learn what the health effects of the pollutants that are coming out from all this burning are. Now, why is this something that we don’t already know?

Interviewee: Lauren Morello

So, this really surprised me when my reporter pitched this story, but it turns out that studies on the health effects of air pollution don’t differentiate what the source of that air pollution is. They really only track the size of pollution particles in the air and generally most pollution comes from things like vehicle exhaust, whereas with a wildfire, you’re burning trees, you’re burning houses, that can have stuff like asbestos and all kinds of plastic, and you’re just burning a crazy mix of things and people just haven’t studied this specifically, and now they’re trying to.

Interviewer: Adam Levy

And now that they are trying to, what kind of things are they looking at to find out what the health effects might be?

Interviewee: Lauren Morello

Well, so there’s some laboratory studies going on looking at how smoke created by burning different things affects the body. It turns out that if you’re burning, say, pine needles, that kind of smoke affects you differently than smoke created by burning plastic. It just affects different types of cells in your body. And then scientists are also setting up long-term health studies of people in areas where wildfires occur pretty regularly and they’re trying to get data that compare people’s heart and lung health, before and after wildfires.

Interviewer: Adam Levy

And it’s not just people that are providing this kind of, I guess, natural experiment.

Interviewee: Lauren Morello

Yeah, this is really interesting. There’s a monkey breeding colony in Northern California in Davis, California. And it’s in an area where there have been a lot of wildfires and the monkeys at this breeding facility live partially outdoors so they’ve been exposed to wildfire smoke. A team of scientists there are studying them and they’ve found that adult monkeys don’t seem to have long-term health effects from wildfire exposure, but monkeys that are babies in summer and fall, when there’s a lot of wildfire smoke, tend to have smaller and stiffer lungs and weaker immune systems than babies that are born in years without a lot of wildfires.

Interviewer: Adam Levy

And all this information, it’s important that we understand it now but it’s potentially even more important for the future.

Interviewee: Lauren Morello

Yeah, I mean this problem of wildfires is intensifying. Climate models project that in a lot of places in the world, fires are going to get more intense or even more frequent, so it would be really good to know what’s in that smoke and what it does to you over the long term.

Interviewer: Adam Levy

For our second story of the week, let’s turn to a study of how research itself is actually carried out and how, in this case, is reviewed. What was this study investigating about the review process?

Interviewee: Lauren Morello

So, this survey looked at which scientists are asked to do peer reviews of other scientists’ papers.

Interviewer: Adam Levy

And they were looking at where peer reviewers are actually based and how often they get asked as a result of that. What were the findings?

Interviewee: Lauren Morello

Yeah, so they were looking at that in part because I think if you talk to editors at journals, they complain that it’s really hard to find peer reviewers and if you talk to many scientists who do peer review, they just say they’re being asked all the time, and there’s this idea that there’s peer reviewer fatigue. So, this study looked at a couple of different databases that track who peer reviews papers, and they found that peer reviewer fatigue is real, at least in developed countries but that in emerging economies, scientists there respond really quickly to peer review requests, they tend to say yes, but they don’t get asked as often. So, there’s like this whole untapped pool of people who seem to really want to contribute.

Interviewer: Adam Levy

So, there’s this disparity where certain reviewers feel fatigued, they’re getting asked to do a lot of reviews, they’re doing a lot of reviews, but then there’s this big pool of ready and willing potential reviewers.

Interviewee: Lauren Morello

Yeah, so in the United States and the UK and Japan, the average researcher writes two peer reviews for every article of their own that they submit to a journal. But in emerging economies, which include like Brazil and India and Poland, those scientists do about 0.6 peer reviews for every paper of their own that they submit. So, there’s a pretty big disparity. I’d say the one big exception in that group of emerging economies is China. So, it produces just under 14% of the world’s scientific articles, or it did during the period that was studied here, and they do about 9% of the reviews. So, per capita they’re still below the US and the UK, but in terms of sheer number of reviews, they surpass the UK in 2015 just because there’s so many more people in China.

Interviewer: Adam Levy

But in general, there is this disparity between the developed reviewers and the emerging economy reviewers. What’s causing that and are there ways that that gap can be bridged?

Interviewee: Lauren Morello

It’s not quite clear why there is this disparity but there are some theories. Scientists in emerging economies might just not be plugged in to peer networks or their networks might be a little bit more limited than scientists in the kind of top research countries. But also, I think a lot of journals are just based in rich countries and so there is this kind of geographic and social network disconnect.

Interviewer: Adam Levy

Okay, but then what can actually be done to, I suppose, broaden these networks out and make them somewhat more inclusive?

Interviewee: Lauren Morello

So, some people who have looked at the data from this survey have suggested that one thing that journals can do is try to recruit more editors from emerging economies and more board members for their journals from emerging economies because these people are just going to be more plugged into the social networks of folks in those countries. And the survey itself found that fewer than 4% of journal editors in the publications that it analysed came from emerging economies. You know, that’s a pretty tiny number considering that China alone published 13% of the world’s scientific articles in 2015, and that’s just one emerging economy on its own, albeit a pretty large one.

Interviewer: Adam Levy

Lauren Morello, thank you for joining us in our London studios. For more on those two stories and other news from the world of science, head on over to nature.com/news.

Host: Shamini Bundell

Or you can follow Nature on Twitter either @NatureNews or @NaturePodcast, or both. And if you want our personal witterings then track me down — I’m @SBundell.

Host: Adam Levy

And find me @ClimateAdam. That’s all for this week. I’m Adam Levy.

Host: Shamini Bundell

And I’m Shamini Bundell. Thanks for listening.

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