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Interviewer: Kerri Smith
Welcome back to the Nature Podcast. The earliest chapters of the human story are set in Africa in the east and south but a new analysis moves back the date and widens the stage.
Interviewer: Shamini Bundell
Also this week, physicists are trying to break their best model of how the universe works. Their most promising weapon is something called a B meson.
Interviewer: Kerri Smith
And, how mathematicians are weighing in on gerrymandering, the practice of redrawing the boundaries of voting areas to one party’s advantage. This is the Nature Podcastfor June the 8th2017. I’m Kerri Smith.
Interviewer: Shamini Bundell
And I’m Shamini Bundell.
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Interviewer: Shamini Bundell
We know modern humans evolved in Africa, but how far back does the human story go? A pair of studies appearing in Natureanalyse some new fossils from an abandoned mining site in Morocco and pin down their age. Kerri explains.
Interviewer: Kerri Smith
Archaeology and mining have a love-hate relationship [Music]. Often, mining operations can turn up fossils, like in the 1920s when an Australopithecus skull was exploded out of some rock in South Africa. But they can also wreak havoc with the structure of a site and obscure valuable evidence. In April this year, palaeontologists in China protested when they found a phosphate mine was destroying a site where some early fossil animals were found. So guess what happened in Morocco in the early 1960s… West of Marrakesh, there’s an area called Jebel Irhoud, a hilly dry landscape with views towards the Atlas Mountains in the distance. Here in 1960, a company mining baryte found a cave and in among the rubble, an ancient looking human skull…
Interviewee: Jean-Jacques Hublin
… And they gave it to the local medical doctor that was working from the mine…
Interviewer: Kerri Smith
Telling the story: archaeologist, Jean-Jacques Hublin.
Interviewee: Jean-Jacques Hublin
In the following years there were, I would say, rather wild excavations and it was mostly gathering stone tools and bones found by the workers.
Interviewer: Kerri Smith
A local archaeologist concluded that the skull was some kind of weird African Neanderthal. And then, done with their project, the mining company dumped all the surplus rock and dirt right where they’d got it from and the site was abandoned. Forty years later, Jean-Jacques Hublin found his mind returning to the site. He’d seen some of the remains years before and wanted to go back for more but the first job they had was rather unorthodox.
Interviewee: Jean-Jacques Hublin
First to build a road to go there and then to bring a bulldozer to clean 200 cubic metres of rocks and dirt.
Interviewer: Kerri Smith
Hublin’s main aim was to find a more robust age for the site, which before had been pegged between 80,000 and 160,000 years old. The age was a puzzle because of what the Jebel Irhoud bones looked like. They were a mix of modern looking traits, like their face structure, for example.
Interviewee: Jean-Jacques Hublin
The face is basically the face of somebody you could meet in the street today.
Interviewer: Kerri Smith
And primitive traits like the shape of the braincase. The mix of features didn’t seem to slot easily into the date range.
Interviewee: Jean-Jacques Hublin
People came with all sorts of funny ideas about that – that they were some kind of African Neanderthals or maybe outbreeds of Neanderthals and modern humans when in the rest of Africa you already had humans very close to us.
Interviewer: Kerri Smith
But when Hublin and a team of colleagues returned to the puzzle of Jebel Irhoud, they were able to come up with a date that made much more sense. The remains are 300,000 years old – 100,000 years older than the previous oldest Homo sapiens’ remains and placing humans earlier and more widespread in Africa than previously thought. This isn’t a back water population of archaic humans but a snapshot of what our species probably looked like 300,000 years back in time.
Interviewee: Jean-Jacques Hublin
So it was a big ‘wow’ and it was a big ‘wow’ because firstly it changed completely the ideas we had about the chronology of the site and we quickly understood that what we had grabbed was a very early phase of the evolution of our own species.
Interviewer: Kerri Smith
By then, Hublin suggests, the face had already modernised, but the brain lagged behind.
Interviewee: Jean-Jacques Hublin
In general, humans and especially paleoanthropologists, they like to think everything starts with the brain and the reality is totally different, so we here have a situation where the brain is sort of lagging behind other parts of the anatomy, like the face.
Interviewer: Kerri Smith
That was Jean-Jacques Hublin. Joining me now in the studio to explore what this means for human evolution more generally, is Nature’s editor Henry Gee. Henry, first of all just go over what the new finds are and the contexts that they add.
Interviewee: Henry Gee
We now know that the Jebel Irhoud homo sapiens were 300,000 years old at least, showing that modern humans lived in Africa for a very long time. This puts other finds into context. There’s been a skull at a place called Florisbad in South Africa which seems to be quite old and sort of modern human and nobody’s really quite believed it but now the Jebel Irhoud find has put that into context.
Interviewer: Kerri Smith
Does this suggest to you or to researchers in the field that modern humans have been modern for longer than we thought they had?
Interviewee: Henry Gee
Yes, but of course, 300,000 old is a long time so modern is a relative term. Certainly more modern than Neanderthals or, well, let’s say, more like us than Neanderthals or homo erectus or other ones. So, what it shows is a very, very long pedigree, specifically of sapiens in Africa.
Interviewer: Kerri Smith
So this pushes back the date of Homo sapiens being all over Africa. Presumably they got there because there wasn’t a Sahara desert at this point?
Interviewee: Henry Gee
Yes that’s correct, the Sahara Desert hasn’t always been as desert-y. It has been quite dry and arid at several times in the past but also it’s been quite lush.
Interviewer: Kerri Smith
Natureeditor, Henry Gee. For archaeologist Jean-Jacques, Jebel Irhoud has been about the journey of the human species, but it’s also been a personal one.
Interviewee: Jean-Jacques Hublin
Well I must say I’m very emotional about that. First of all I was born in North Africa and when I was a child I had to flee Algeria and move back to France and so it has a lot of emotional load to return to Rabat, to do my work, and now to see that we came to such an amazing conclusion after this very long journey, it blows my mind somehow.
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Interviewer: Kerri Smith
That was Jean-Jacques Hublin who’s at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Both papers are at nature.com/nature. There’s also a News & Views article and a news story helping to analyse the results.
Interviewer: Shamini Bundell
Coming up in the news, a telescope in jeopardy. In the Research Highlights, leaky gas wells, and Egyptian mummy DNA.
Interviewer: Kerri Smith
But first, whether it’s Donald Trump’s position on climate change or the impact of Brexit on UK science funding, politics has a big influence on science. But what about the other way around? How much does science influence politics? Well, a feature in this week’s Naturetakes a look at how science and mathematics could play a part in how political systems function. Here’s Shamini.
Interviewer: Shamini Bundell
Democracy: one person, one vote – majority rule. It all sounds simple enough but in practice voting systems, like everything else in life, get complicated quickly. One element of this is in the drawing of voting maps. Many democratic systems involve electing local representatives for particular areas. Take the US. Each state is divided into districts and each district votes for a member of the US House of Representatives but this can sometimes lead to some unexpected results. Here’s an example.
Interviewee: Jonathan Mattingly
In 2012 in North Carolina, the state wide election was just over 50% for the Democratic Party.
Interviewer: Shamini Bundell
This is Jonathan Mattingly, a mathematician at Duke University in North Carolina.
Interviewee: Jonathan Mattingly
And yet when the votes were tallied and the congressional delegation was set, of those thirteen, nine were Republican and 4 were Democrat. So only four, even though the Democrats had gotten 50% of the vote.
Interviewer: Shamini Bundell
It appeared that the distribution of votes within each district didn’t match that of the state as a whole.
Interviewee: Jonathan Mattingly
And I knew a lot of people who were outraged by that. But it led me to think a little bit objectively and say, well, people are saying half of them should have been Democrats at least. And I was like, well, I’m not so sure about that.
Interviewer: Shamini Bundell
People don’t distribute themselves around a state homogenously; they cluster and their politics can factor into this. So could the apparent bias in the North Carolina result be due to natural social geography? Or could it be, as some were claiming, because the district boundaries had been deliberately drawn to include or exclude certain groups of people from certain districts.
Interviewee: Carrie Arnold
Gerrymandering has been around for probably a little over 200 years now.
Interviewer: Shamini Bundell
This is Carrie Arnold, whose feature in this week’s Naturelooks at Jonathan’s work as well as the science of what is known as Gerrymandering, named after a former governor of Massachusetts, Elbridge Gerry, and the salamander-like district shapes his team drew in 1812.
Interviewee: Carrie Arnold
I mean, they created shapes that would probably impress even Picasso.
Interviewer: Shamini Bundell
Gerrymandering involves redrawing voting maps to change the outcome of a vote in a particular direction. This could be by splitting up a block of hostile voters so that their influence is diluted into different districts, or, by packing all your opponents into a single district to ensure that you win all the others. Gerrymandering is a particular problem in the United States, as Carrie explains.
Interviewee: Carrie Arnold
In the US, in nearly all of the states, the party that’s currently in power can draw the lines to benefit their own party and the Supreme Court has struggled with when to intervene because they haven’t really found a way to say when does it become unconstitutional? What mathematicians and statisticians and political scientists want to do is create some way to quantitatively evaluate voting districts for partisan Gerrymandering.
Interviewer: Shamini Bundell
And this is what Jonathan Mattingly was starting to think about back in 2012 in North Carolina. How can you quantify how much Gerrymandering has actually gone on?
Interviewee: Jonathan Mattingly
We really want to try to identify some signal that maybe one could use to evaluate whether a district was reasonable, because of course when drawing a district there are many political considerations that go into that.
Interviewer: Shamini Bundell
Because of these many considerations, deciding if a map is fair isn’t as simple as asking a computer to find the one optimal map and then comparing it. What an algorithm can do, however, is create a range of different options based on optimising a few simple criteria, such as having equal numbers of people in each district; not splitting up ethnic minority groups; and forming compact, and contiguous shapes.
Interviewee: Jonathan Mattingly
What we decided to do was to write a computer algorithm that generated a hundred thousand redistrictings of the state of North Carolina.
Interviewer: Shamini Bundell
These thousands of maps represented a spread of the most reasonable options, based only on the accepted criteria, without any partisan gerrymandering. These could then be compared to the real maps used to see if the shapes drawn fit within this range of unbiased options. If the real maps were significantly less compact, for example, this could be an indication of how much Gerrymandering might have gone on. Carrie Arnold…
Interviewee: Carrie Arnold
What he found was that the 2012 North Carolina district maps were more gerrymandered than every last one of the computer-generated maps.
Interviewer: Shamini Bundell
The 2012 maps were filled with such specific and suboptimal shapes that they were very unlikely to have arisen with significant Gerrymandering.
Interviewee: Carrie Arnold
But he also compared them to a bi-partisan committee who had drawn up a set of maps just as a hypothetical exercise and he found that the bi-partisan maps were actually less gerrymandered than 75% of the computer-generated maps.
Interviewer: Shamini Bundell
So it is possible for humans to draw reasonably fair and sensible maps. Persuading every state to use bi-partisan committees sounds like a good option if it can be made to work. But in the meantime algorithms like Jonathan’s, or others that are being developed, could be used by judges ruling in cases where existing maps are being challenged, and with the next opportunity for redrawing the US maps coming up in 2020, Carrie Arnold thinks this is an area of politics in which science and mathematics will soon be called upon.
Interviewee: Carrie Arnold
When it does come time to redraw the voting districts in a few years, there will be a clearer set of criteria for legislators to use in order to draw their districts and be as fair as possible.
Interviewer: Shamini Bundell
That was Carrie Arnold. Her full feature is available to read now at nature.com/news, and includes more information on Jonathan Mattingly’s work. Time now for the Research Highlights with Adam Levy.
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Interviewer: Adam Levy
The US is dotted with natural gas storage wells and one in five of them is so old that they could fail and release harmful gas. A new census of gas wells in the US finds almost 3,000 at risk of leaking. They’re mostly wells that were built just to get gas or oil out, not to store gas at high pressure. Two hundred wells from the sample were over a century old. Gas well safety regulations are being redrawn because of a giant gas leak in 2015. A storage well in California failed leading to the biggest accidental release of greenhouse gases in US history. More in Environmental Research Letters.
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Interviewer: Adam Levy
DNA extracted from Egyptian mummies pins their closest kin to the Middle East, suggesting that North Africans might have different routes than people in South and Central Africa. The new study would cover genetic material from 90 mummies – the oldest over 3,000 years old. To avoid problems of contamination which had scuppered previous efforts, they took DNA from bones and teeth instead of soft tissue and carefully screened it to make sure no modern DNA had stuck in. Their conclusion – that there were close lines between Egypt and the Middle East – aligns with archaeological finds and documents. Nature Communicationshas the paper.
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Interviewer: Kerri Smith
A big thank you to everyone who filled in our listener survey. The survey is now closed and we’ve begun to look at what you’ve told us about the show, like, where you listen to it: on your smart phones most of the time; at home; on your commute; and even while cooking. That information helps us make a show that holds your attention through the subway journey or while you’re figuring out if you bought onions.
Interviewer: Shamini Bundell
When we asked how you find new podcasts, many people said ‘word of mouth’ so we have a little favour to ask: if you know someone who might enjoy this show, please tell them.
Interviewer: Kerri Smith
We’d love our show to reach even more pairs of evidence-loving ears. Tell your friends to Google Nature Podcastor find us on iTunes, or their preferred pod-catcher.
Interviewer: Shamini Bundell
Now, on with the show
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Interviewer: Shamini Bundell
The standard model is one of the crowning achievements of 20thcentury physics. It’s a nifty set of equations that describes many of the fundamental workings of the universe, from why matter has mass, to the forces that bind atoms. It’s incredibly accurate but theorists know it can’t be the end of the story. After all, there are some tiny things missing, like, oh you know, just gravity and dark matter. One way to go beyond this theory is to discover new particles that don’t fit and for a few years physicists at the Large Hadron Collider or LHC have been trying to find some, by smashing protons together at record energies and scouring the debris. So far no luck, but there is one ray of hope. Looking at particles we already know about, behaving weirdly. Physicists think this has been happening with the B meson, and there’s a chance that an entirely new particle is at the root of the weirdness. In Naturethis week, two reviews examine the evidence and reporter Lizzie Gibney got the details from Nature’s Physics Editor, Leonie Mueck.
Interviewer: Lizzie Gibney
So in the LHC’s earliest days most physicists thought that we’d get breakthroughs from seeing entirely new particles, but that hasn’t happened yet. How are physicists hunting for these new phenomena in this case?
Interviewee: Leonie Mueck
The trick is not to go to super high temperatures and produce new particles directly, but to do very high precision measurements of specific decays and all of these decays that people are looking at, at the moment, involve a B meson which is a particle composed of a quark and an anti-quark – and the quark is a beauty quark, or bottom quark. Yeah – beauty is often used because it sounds prettier, literally.
Interviewer: Lizzie Gibney
How does looking at these decays then tell us about possible phenomena outside of our standard model?
Interviewee: Leonie Mueck
New particles can influence how a decay works, how we get from A to B, from starting to end products, because there’s often lots of different interactions involved. If we see any deviations in the quantities of the end products from what we expect, you can guess or infer that there must be some other particle interacting during this decay.
Interviewer: Lizzie Gibney
So this change from one particle into a bunch of others might not be as straight forward as we think; something else is affecting it.
Interviewee: Leonie Mueck
Exactly.
Interviewer: Lizzie Gibney
So in these two reviews which you edited and which Nature’s publishing this week, the authors sum up a whole bunch of different such anomalies. Can you tell us a little bit more about them?
Interviewee: Leonie Mueck
One type of decay that they look at are called flavour-changing neutral currents and those are processes involving the weak force and any deviations in how many decays of a specific kind happen could point towards deviations from the standard model. One of the decays where we’ve seen real discrepancies are decays of a B. These deviations are not very large at the moment; they’re only about 1.6 standard deviations and particle physicists are very strict about when they claim that they’ve really observed something because there’s so many analyses done each year that you must get false positives every once in a while – it’s just statistics – so you need 5 standard deviations to claim you’ve observed something, so we’re really rather far from it but that’s a little hint that there might be something there.
Interviewer: Lizzie Gibney
And what seems to be interesting here is that there’s lots of little hints that all seem to point in the same direction, so B mesons have also been playing up in other ways, haven’t they?
Interviewee: Leonie Mueck
They’ve been playing up in another really interesting way, especially in questions surrounding lepton universality. Leptons are electrons but there’s also slightly more exotic leptons called muons and taus and these leptons should all behave in the same way except they have different mass so that’s the only thing that should make them behave differently. But there’s hints that they don’t and that has also been measured in B meson decays by three different experiments – that’s what makes it really, really interesting and hard to dismiss and the combined deviation from the standard model is about four sigma, so we’re really getting into observation territory here.
Interviewer: Lizzie Gibney
So all of these different tiny anomalies from deviations from the standard model, but they all potentially point to something out there. Could that something be the same thing? Is there a new particle or way of describing what’s going on that would match all of those different anomalies?
Interviewee: Leonie Mueck
It’s very difficult to say because we haven’t really constrained very well what that new particle could be but there are similar interpretations out there, or similar ideas for all of these little hints.
Interviewer: Lizzie Gibney
Amazing, so it’s kind of like we’re feeling around in the dark and possible bumping into the same thing from different directions but we don’t really know yet if that’s the case.
Interviewee: Leonie Mueck
Yeah, well, there might be at least a candle in the room.
Interviewer: Lizzie Gibney
But, of course, as you hinted before, there’s a massive caveat in that this does happen in particle physics sometimes, doesn’t it? We have anomalies, we’re processing enormous amounts of data and as a result we see what looks like a difference from what we expect, which then later goes away. Is that possible here?
Interviewee: Leonie Mueck
That is still very possible, yes. I wouldn’t bet on anything until I’ve seen 5 standard deviations. But since three different experiments with very different experimental set ups have seen it, it would be a big coincidence.
Interviewer: Shamini Bundell
That was Leonie Mueck, editor of Physical Sciences here at Nature, talking to reporter Lizzie Gibney. Find the two review papers, which details these particle decay discrepancies, plus an editorial at nature.com/nature.
Interviewer: Kerri Smith
Time for this week’s News Chat and on the line from Washington DC is American Bureau Chief, Lauren Morello.
Interviewee: Lauren Morello
Hello.
Interviewer: Kerri Smith
Now, unsurprisingly we are going to start with Trump and the Paris deal because last week he pulled the US put of that deal.
Interviewee: Lauren Morello
Yes. On Thursday, the president held a press conference in the White House rose garden and announced that he was pulling the US out of the Paris deal. He says that the Paris deal is unfair to the United States and it would give an advantage to China and India.
Interviewer: Kerri Smith
What would you say is the overall reaction in the states?
Interviewee: Lauren Morello
Definitely among the scientists that we talk to there’s a lot of frustration and a lot of them are just simply dismayed and have pointed out that the Paris agreement was set up so that each country determines its own emissions pledge, its own plan for reducing greenhouse gas emissions, even the level of that commitment. I think among the American public, it’s interesting, there’s at least one poll that’s come out since Trump said he was pulling the US out of the agreement and it shows a majority of Americans would have preferred to stay in the Paris Agreement.
Interviewer: Kerri Smith
Since the news came out – this is obviously almost a week ago when – as we released this podcast – what has been some of the fallout, some of the nuance since then that you guys have been reporting on?
Interviewee: Lauren Morello
We’ve seen a ground swell of support for the Paris Agreement amongst cities and states and businesses here. There’s a group of a little over a dozen states that has emerged; they’re calling themselves the US Climate Alliance and pledging to uphold their chunk of the United States Paris Commitment. There are major cities that have made similar pledges including New York City and Washington DC, where I am. And there are major businesses including Apple and Facebook and Google and even some businesses that have interests in fossil fuels that have been lobbying the White House to stay in the agreement and have said that they will keep up their own climate pledges even though the US has pulled out of Paris. This is heartening for people who wish that the United States hadn’t pulled out of the Paris Agreement. They see that about a quarter of the US population is right now in areas that have pledged to uphold the Paris goals.
Interviewer: Kerri Smith
If we look at how the climate is going to fair with one fewer country in the accord, do you think it will make that much difference overall?
Interviewee: Lauren Morello
It’s interesting. I think a lot of the scientists we spoke to said that, you know, it’s not clear that it would make a huge, immediate impact on emissions but it’s hard to say what will happen over time. Other countries, including China, which is the world’s biggest emitter, have reaffirmed their commitment to the Paris goals but I think a lot of researchers and climate policy experts worry that the US leaving the agreement will give cover to other countries that want to weaken their Paris goals or even consider leaving the accord.
Interviewer: Kerri Smith
For those of us who like to plan, who like a bit of long-term forecasting, what’s the timeline for how this will now progress?
Interviewee: Lauren Morello
So, under the Paris Agreement, countries can’t withdraw until 3 years after the Agreement went into effect. Since the Agreement took force on November 4thof last year, that means the US would have to stay in it until November 2019, and there’s actually an additional one year notice period after that which means that the US couldn’t ultimately withdraw until right around the point in early November 2020 when we’ll have our next presidential election. So if Trump doesn’t run, or loses his bid for a second term, the next president could throw us back into the accord.
Interviewer: Kerri Smith
Do you think this is likely to be an issue that people will campaign on and that voters will vote on in the next election?
Interviewee: Lauren Morello
I think there is a much bigger chance now that Trump has pulled the country out of the Paris accord. Without this I’m not sure that climate would have risen to become a top tier issue but I think now definitely you will see this.
Interviewer: Kerri Smith
Now, as well as thinking about the Paris Agreement, this week we’re going to turn our attention to that other thing – that other favour topic, NASA – and specifically some funding for a telescope that looks a little bit like it might be in jeopardy?
Interviewee: Lauren Morello
Yes. This is the Wide-Field Infrared Survey Telescope, or WFIRST which is NASA’s next big space observatory. It’s supposed to launch in 2025 and it’s going to do things like try to get the first direct view of an exoplanet and determine how dark energy is driving the expansion of the universe, but right now its budget is rising too quickly for NASA’s comfort.
Interviewer: Kerri Smith
As in, it’s costing more than they thought it was going to?
Interviewee: Lauren Morello
Right. Every ten years, astronomers and astrophysicists rank their science priorities and the last time they did this was in 2010 and this telescope was their top ranked big space mission and at that point in 2010 it was estimated to cost 1.6 billion. A few years after that, NASA got an unexpected gift from the National Reconnaissance Office which is a spy agency. They gave NASA a huge mirror from their own stock of spacecraft parts and that allowed NASA to upgrade WFIRST’s capabilities but it also raised the cost. The current estimated cost is 3.2 billion.
Interviewer: Kerri Smith
This is concerning, and what’s to be done about it?
Interviewee: Lauren Morello
Yeah, I’ll step back for a second and say part of the reason this is of such concern for NASA is that they had a pretty bad experience with the James Webb Space Telescope which is supposed to launch next year. When James Webb was originally proposed its budget was about a billion and now it’s climbed to almost 9 billion, so NASA wants to keep WFIRST from going down that path. So they have a couple of different strategies that they can use. One is simply just to collect less data, to keep the same instruments and capabilities but operate them for a shorter amount of time than they’d like to. The other thing they could do is downgrade some of the instruments. They added something called a corona-graph which blocks the light from a star and allows you to see the planets that orbit it. They added that after they got the bigger mirror so they could scale back plans for that corona-graph for example and save some money.
Interviewer: Kerri Smith
Thanks Lauren. Of course, we’re not the only news outlet covering Trump and the Paris Agreement but if you want to know how scientists feel about it and how it might affect the research community, you know where to come – nature.com/news – where you’ll also find details of the telescope in jeopardy.
Interviewer: Shamini Bundell
That’s all we have time for this week. In the meantime, the third of our grand challenges on food security just landed on Monday. Check it out in all the usual places. I’m Shamini Bundell.
Interviewer: Kerri Smith
And I’m Kerri Smith.
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