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  • NATURE PODCAST

Ancient 'giraffes' sported thick helmets for headbutting

Listen to the latest from the world of science, with Benjamin Thompson, Nick Petrić Howe and Shamini Bundell.

In this episode:

00:33 A headbashing relative gives insights into giraffe evolution

How the giraffe got its long neck is a longstanding question in science. One possibility is that giraffes evolved longer necks for sexual competition, with males engaging in violent neck-swinging fights. Now, a team have described fossils of an ancient giraffoid species with a thick headpiece adapted for fighting, which could add weight to this hypothesis.

Nature News: How the giraffe got its neck: ‘unicorn’ fossil could shed light on puzzle

05:18 A wave of resignations signals discontent in academia

Around the world, the ‘great resignation’ has seen huge numbers of workers re-evaluating their careers and lifestyles and choosing to leave their jobs following the pandemic. Academia is no exception, with many scientists deciding to leave the sector in the face of increased workloads, systemic biases and pressure to publish.

Nature Careers: Has the ‘great resignation’ hit academia?

10:34 An emergency fix gets MAVEN back on track

Earlier this year, NASA’s MAVEN spacecraft, which has been orbiting Mars since 2014, developed some serious equipment issues that prevented it from keeping its correct orientation in space. In a race against time, a team on Earth fixed the problem by developing a system that allowed the spacecraft to navigate by the stars.

Space.com: NASA's Mars MAVEN spacecraft spent 3 months on the brink of disaster

14:28 The Perseverance rovers continues its rock collection

NASA’s Perseverance rover has arrived at an ancient Martian river delta where it will spend the next few months exploring, while scientists assess where to drill and extract rock samples. It’s thought that rocks from this region have the best chance of containing evidence of Martian life, and plans are being developed to return them to Earth in the future.

Nature News: NASA’s Perseverance rover begins key search for life on Mars

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doi: https://doi.org/10.1038/d41586-022-01601-6

Transcript

Listen to the latest from the world of science, with Benjamin Thompson, Nick Petrić Howe and Shamini Bundell.

Host: Benjamin Thompson

Hi, Benjamin from the Nature Podcast here. We're going to change things up a little bit on the podcast this week, and we're going to take a deep dive into some of the stories that have appeared in the Nature Briefing over the past few days and weeks. Joining me to do so are Nick Petrić Howe. Nick, how you doing today?

Nick Petrić Howe

I’m very well, thank you, Ben.

Host: Benjamin Thompson

And Shamini Bundell.

Shamini Bundell

Hey, Ben.

Host: Benjamin Thompson

Well, here we go then. We’ve got a few stories to talk about this week. Shamini, would you like to go first on this extended Briefing chat? What have you got?

Shamini Bundell

So, I have some exciting giraffe science for you this week. This is, once again, an ancient creature – I do love those fossils – and it is a relative of modern-day giraffes, although one that looks quite different. It has been described in a paper in Science and I've been reading about it in Nature, and the paper includes an artist's reconstruction of what they think this giraffe relative looked like from the bones that they found.

Host: Benjamin Thompson

Okay, so when I think giraffe, I'm thinking long neck, I'm thinking long limbs, I'm thinking that kind of cool, mosaic pattern. How different is this giraffe relative to what I'm thinking of?

Shamini Bundell

Well, it doesn't have as long a neck, I have to say. I don't know if you saw it whether you would immediately think giraffe. They think it may have looked more like an okapi – those forest creatures that are another giraffe relative, just with slightly shorter necks. But this particular species has a really noticeable weird feature, which is this hard dome on its head. The thing it reminded me of was Pachycephalosaurus – a kind of dinosaur with a bony head which was in The Lost World film. One of the characters referred to them as Friar Tuck because it looks like it's got a little bald head there. So, it's got these domes and in the artist’s reconstruction are these two muscular short-neck giraffe-type things trying to sort of like headbutt each other or attack each other, which is what they think that was for.

Nick Petrić Howe

So, the hard head thing may be a way to sort of protect themselves when they do this sort of headbutting. So, is this related to some kind of sexual selection or anything like that?

Shamini Bundell

Yeah, so a lot of hoofed mammals, which giraffes are part of, so think of like deer and bison and antelope, a lot of them have this sort of fancy headgear. And if you think about stags fighting each other, they're sort of crashing their heads and their antlers together and fighting for mates or dominance. So, the researchers have looked at these bones, which they have sort of found in northern China and said, ‘Yeah, if you look at the neck and the vertebrae in the head, we think this evolved for male-to-male combat.’ And this thick layer on top of the head, which has layers of keratin 5-centimetres thick, that would have indeed been sort of protecting the brain during that activity.

Nick Petrić Howe

And so, when we think of modern giraffes, they don't have such headgear, so how do these guys sort of relate to these ancient headbutting creatures?

Shamini Bundell

Well, they do have little horns and they've got these weirdly long necks. And actually, one of the interesting things about finding this ancient giraffe species has been whether it can add into the debate about modern giraffes and why they do have such long necks because that's a pretty sort of classic evolutionary question. Why do giraffes have these like massively long necks where they have to pump their blood 2 metres up into their head so that they don't faint or have a stroke. They have to have like really high blood pressure and it has to be managed really well. So, it's a really big cost to do that. It must have some good reason. But what reason is it? So, a classic theory as to why a giraffe has a long neck is so it can eat from the tallest trees, reach the leaves that other animals can't reach. But there's some evidence against it because giraffes actually don't tend to eat from high up. They tend to eat from the lower levels. And one study found that the tallest giraffes weren't necessarily any more likely to survive a drought when there wasn't much food. So, is it just the food thing, or has it evolved through some element of male-male competition?

Host: Benjamin Thompson

And this is where these ancient relatives come in, showing that they do have this male-male competition, and maybe giving some insight into what's going on with modern giraffes. Is that right?

Shamini Bundell

So, it just sort of adds weight to the fact that, in the giraffe family, this kind of competition and combat has been significant in their evolution. So, for modern giraffes, the idea that the long necks are really about the males fighting each other and sort of whacking each other with their necks. That has been an idea for a while. The theory is described as necks for sex, but not everyone has been convinced about that. An argument against it is that, well, there's no sexual dimorphism in giraffes. The males don't have longer necks than the females. So, is it the food? Is it the sexual selection? So, this new species, maybe it contributes to that argument. Maybe it shows that sexual selection is a really particularly strong pressure. And maybe that will change how people think about how the giraffes got their long necks.

Host: Benjamin Thompson

Well, Shamini, that is a terrific story. Thank you so much for bringing it to today's extended Briefing chat. Let's move on. Nick, you're up next. What have you got for us this week?

Nick Petrić Howe

So, for my story this week, I was reading an article in Nature about the great resignation, which is something you might have heard of, and how it's hitting academia.

Shamini Bundell

So, is the great resignation some sort of organised protest? Or is it just the fact that a lot of people are leaving their jobs in academia?

Nick Petrić Howe

It's more about people leaving their jobs everywhere, partly in response to the pandemic. So, it's mainly focused in the US, but also places like the UK and Australia have seen similar things, where many people are sort of reassessing their life values and deciding, actually, they want to do something else, and so they're leaving their jobs. And this also seems to be the case in academia, which is what this story is about. And we've talked before on the show about the discontent amongst academics and it seems, particularly at the mid-career stage, a lot of people are getting pretty fed up and are leaving academic positions to go and work somewhere else.

Host: Benjamin Thompson

Yeah, I mean it does seem like maybe two graphs crossing over here, Nick. As we've discussed in the past, you're absolutely right, like a lot of short-term contracts can lead to career dissatisfaction. And if a great many people are thinking, ‘Well, the world's changed, now it's time for me to change things up,’ that that could hit academia particularly hard.

Nick Petrić Howe

Yeah, that's right, and it's also just a culmination of different things that have been affecting academia for a while. So, a lot of people who were interviewed for the article spoke about how they're just getting increasing workloads, more pressure, and less support from their institutions as well. And essentially, COVID may be the straw that broke the camel's back. It's interesting as well that many of the people that are leaving academia are in tenured positions, which is where you have a permanent safe position, and so they're not at risk of losing their job. Their contracts aren't running out. They are choosing to leave academia. And in many cases, they seem to be happier doing so. Some people are describing how they've gone from working 80 hours a week in academia, and now have moved to industry where they work 40 hours a week and earn twice as much as they did there.

Shamini Bundell

Wow, so this is sort of a separate issue from like leaky pipeline issues. This is a whole load of established people just saying, ‘Nope, I can do better.’

Nick Petrić Howe

Yeah, it's established people, people that are mid-level as well. There are a lot of people leaving academia. But it's interesting that you bring up the leaky pipeline because what some people were talking about in this article is how they're pushed out, in a way, by sort of systemic biases. So, there's an academic in this article, for example, who was given their position, and it was specifically a position for someone from an underrepresented group, but they may have to leave the job because they've been unable to secure funding. And they say part of the reason is they were given inadequate space and equipment, and so they were unable to do enough research to sort of get the grants in the first instance. And there was one person as well in the article who got what they considered to be a racially insensitive email and for them, that was the sort of final straw.

Host: Benjamin Thompson

And of course, all of this has potentially future consequences in terms of maintaining a scientific workforce. Does the article have any ideas of what institutions or organisations are trying to do to reverse this or improve things for researchers to stop them wanting to leave?

Nick Petrić Howe

Yeah, so the article talks about one place where people are staying and people who are at risk of losing their jobs, people who have been facing additional pressures during the pandemic, which is women. We've spoken before on the podcast and we've talked about at Nature how the pandemic has been particularly difficult for women with additional pressures with childcare and that sort of thing. And this place they talk about in the article is the Virginia Commonwealth University, and this place won a US National Science Foundation grant specifically to increase recruitment and retention of science faculty who are women. And one of the key members of the team there, they credit the grant with preventing loss of women and also, they talk about how it's really important to retain women because then you have the sort of mentorship that can allow people to sort of come up through in the workforce. So, there are places where this is happening, and they can maybe be places to look to, to try and prevent this sort of loss of talent from academia.

Shamini Bundell

So, it seems like a mix of resources and funding and support are really needed to make academia a more attractive prospect.

Nick Petrić Howe

Indeed, and one person quoted in the article, they sort of lament how the career goalposts keep shifting. They say that when they started in 2015, 10 first author papers would write your ticket anywhere and now they say that they have 29 publications and 16 of them are first author, but she's not sure whether that's enough to secure a tenure-track position. And she studies motivation and irrational decision making and she actually says, at a certain point, it doesn't make sense to continue what we call costly persistence.

Shamini Bundell

I'm sure this is a topic close to many of our listeners’ hearts, so we'll be keeping an eye on that. That just leaves one final story for today. Ben, what have you got for us?

Host: Benjamin Thompson

Well, actually, Shamini, let’s go for two final stories, and they’re both about Mars. And the first one, well, it’s quite exciting, and I’ve read about it on space.com, and it’s about a NASA spacecraft that’s been orbiting Mars, and it’s called MAVEN, which has been circling the red planet since 2014. Now back in February, some parts of this spacecraft stopped working and it was a bit sort of touch and go really to see whether it could be repaired at all, and this spacecraft has some pretty important functions.

Shamini Bundell

Oh, no. Well, what was it actually supposed to be doing?

Host: Benjamin Thompson

Well, MAVEN stands for Mars Atmosphere and Volatile Evolution, and this spacecraft, it’s job is to explore Mars's atmosphere and look at what happens when kind of solar flares hit it and that sort of thing. And actually, it has some pretty important sub-work as well, which is acting as a relay to rovers on Mars. And on this spacecraft are these two things called Inertial Measurement Units, IMUs, right, so IMU-1 and IMU-2, and these two things have a really, really important job and that is making sure that the spacecraft has the correct orientation in space because things on spacecraft need to point in the right direction. Now, these two units have not been well. IMU-1 started having problems back in 2017 and IMU-2, well, it was running out quicker than expected. It has a finite lifespan and this was going quicker than was thought. And in February of this year, well, the team on Earth lost contact with MAVEN, and when they regained it, they showed that it couldn't use either of these units which, as you might imagine, was pretty bad.

Shamini Bundell

Sounds like a disaster.

Host: Benjamin Thompson

Yeah, I mean, not an ideal situation. So, the spacecraft did some kind of switch it off and on again, right, and they managed to get the second backup IMU-2 working. Now, IMU-1 was out for the count but of course, as I said, IMU-2 only will last for so long. And so, what the spacecraft did, it went into what's called safe mode. It shut down everything that wasn't needed, right. So, it couldn't do any scientific work. It couldn't do anything except wait for instructions back from Earth. And this is where let's science the heck out of it happens. And it was a bit of a race against time because the researchers suggested that this backup IMU unit would last until October and then shut down completely, at which point the spacecraft would potentially just be lost, would cease working. So, what they did, they developed something called all-stellar mode, right. Now, this is something that spacecraft can use to orient themselves and what essentially it does is it uses the position of the stars and compares that to kind of an internal map to say, ‘Well, you’re pointing in that direction so this is where you must be.’ Now, this is not as accurate as these IMUs, but it will do the job. But it takes time to develop, right. So, there’s this race against time to develop this before October. Now, the team had planned to do this at some point but obviously necessity is the mother of invention, and they suddenly had a very hard deadline. And so, absolutely smashed it, and in only a couple of months managed to develop this system and upload it to MAVEN.

Nick Petrić Howe

And has this now fixed the problem? Is it functioning as it should?

Host: Benjamin Thompson

It seems to have, in the short term, fixed things. So, it took a little while to test all the systems, make sure it was doing its job and all the rest of it, and turn back on the science instruments as well. But it is working. It’s a bit of a shame because they lost a few months of recording things and missed some solar activity and how it affected Mars, but it is still functioning, which is great. However, there is a ‘but’ coming.

Shamini Bundell

Oh no, is it not going to last? Is it going to break again?

Host: Benjamin Thompson

The stars aren't going anywhere, so this kind of all-stellar mode will last for a good long while. The problem is it’s not the most accurate, right, so you need an IMU to try and do maybe some fine orientation and what have you. And so, this backup one, IMU-2, has been switched off, right. And the researchers are really trying to eke out its lifetime because they're going to need it in future. But they also need to work out ways that they can get away with not having it. And the reason that this is important is because, well, NASA have extended the lifetime of this spacecraft once and are potentially going to extend it even further to 2033, where it is going to be involved as a relay to kind of talk to rovers on Mars, and it could well be involved in the sample return mission that NASA have got planned for the future. And that is the subject of my second story.

Shamini Bundell

Oh, yes. So, we talked about the various Mars missions launching back in 2020. So, how are the rovers on the surface doing right now?

Host: Benjamin Thompson

Well, this story is about one very specific rover, the little rover that I know we've all talked about on the Briefing chat before, and it's the Perseverance rover which, 15 months ago, landed on Mars, and it's been obviously doing a lot of science. But now, it's really ramping up on its hunt to find evidence potentially of ancient life in the long distant past.

Shamini Bundell

Oh, that's what we're all waiting for – life on Mars? Has it found it yet? I guess not. I probably would have heard.

Host: Benjamin Thompson

I don’t think it’s a spoiler here to say no it hasn’t yet. But what it is doing is it's looking to collect some rock cores, and specifically it’s looking in an ancient river delta in the Jezero crater on Mars where it is situated. And what's happened in the last few weeks is that it's had a look around, and it's ground down this rock into dust to see what it was made of, and specifically to see what sort of sediments it was made from because river sediments here on Earth are usually teeming with life. So, the team have reasoned that if they can look at an ancient river delta and have a look at some of the rock there, they could potentially look for the chemical signals or evidence of life.

Shamini Bundell

Oh, fascinating. And so, you said it's been gearing up and doing even more science. Are we still awaiting the results of all that?

Host: Benjamin Thompson

Well, when it comes to rock collection, Shamini, I think the game is just gearing up, to be honest with you. What's going to happen now is that the rover is going to be rolling around looking for potential rocks to dig up. They've looked at the sediments and now they're actually going to look for some rock samples, right, and there's obviously a lot of discussion over what exactly it should dig for, particularly when it comes to returning the samples to Earth, which is not an easy thing to do, right? So, it's going to choose very, very carefully, and maybe drop some of these samples off. And it turns out that one of the areas that it's kind of in is pretty flat, it’s relatively free of giant rocks, so it could be an excellent place for a future sample retrieval mission.

Nick Petrić Howe

And one of the things with Perseverance, Percy, is that it has this little helicopter who's been helping it out and recently we talked about how it's maybe going to help survey like the environment and help Perseverance find things to look at. Is that how it's going to find these rocks here?

Host: Benjamin Thompson

Yeah, so Ingenuity has been helping the rover find its way, and it was originally slated to do 5 flying missions and currently it has done 28.

Shamini Bundell

Ah, Ingenuity doing so great.

Host: Benjamin Thompson

Yeah, but it may not do too many more, it has to be said. So, the Martian winter is coming in. It's getting dustier and colder. And that might prevent kind of it solar charging its batteries and flying about. But this article ends with a lovely quote one of the researchers that says, ‘No matter what happens, Ingenuity has been successful,’ and I think we can agree on that.

Nick Petrić Howe

Ah, and I think we've talked about this a little bit on the podcast before as well but, now they're actually starting to pick rocks that may be going back to Earth, have scientists started to put together plans for exactly how they're going to bring them back to Earth?

Host: Benjamin Thompson

Yeah, so NASA and the European Space Agency are planning a US$5 billion mission to take the samples back, and this includes a rover, various spacecraft to fly them off the surface and catch them in orbit and send it back to Earth. Obviously, very, very complicated to do. And it has been made more complicated, in fact, by the war in Ukraine, because ESA has halted cooperation with Russia, so that looks to have messed up the timelines when this might happen somewhat. But I think what is good is the sample tubes that the rocks will be collected in are designed to last for decades. So, it might take a bit longer, but eventually, hopefully, they will be brought back to Earth, and we'll see what they contain.

Shamini Bundell

Well, brilliant. Thanks, Ben. It's always good to have some updates and make sure everything's going well on Mars. And thanks, everyone, for some great science stories this week.

Nick Petrić Howe

Yeah, it’s been a lot of fun. And listeners, if you’ve enjoyed listening to us ramble about science, then maybe you would enjoy reading the stories as well. There’ll be links to them in the show notes, along with a link of where you can sign up to the Nature Briefing to get more of these kinds of stories. I’m Nick Petrić Howe.

Shamini Bundell

I’m Shamini Bundell.

Host: Benjamin Thompson

And I’m Benjamin Thompson. See you next time.

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