Missing foot reveals world’s oldest amputation

Host: Benjamin Thompson

Welcome to the Nature Podcast. This week: evidence of amputation surgery dating back 31,000 years.

Host: Nick Petrić Howe

And the latest from the Nature Briefing. I’m Nick Petrić Howe.

Host: Benjamin Thompson

And I’m Benjamin Thompson.

[Jingle]

Interviewer: Benjamin Thompson

Think about surgery today and you might picture a shiny operating theatre full of advanced technology and specialist medical staff. But the story of surgery goes back a long way, before germ theory, before Hippocrates, even before the invention of metal tools. Until now, one of the earliest examples of a complex medical procedure was seen in the skeleton of a Neolithic farmer in France who had had part of their left arm amputated about 7,000 years ago. But this week, a paper in Nature suggests that surgery may be far older than we thought, after researchers found evidence of an amputation that occurred around 31,000 years ago. The story begins in a cave in the rainforest in the east of Indonesian Borneo. It’s in a pretty remote location and getting there is a bit of a trek, as Adhi Agus Oktaviana, a PhD student from Griffith University in Australia, one of the authors of the new paper, explains.

Interviewee: Adhi Agus Oktaviana

If we go there from the airport, we need around six hours with a car and then three hours with a small boat to the base camp. And the next three hours, small boat again, and then walking. Yeah, it’s like a fairly remote area. There’s a lot of caves there, around 100 to 300 metres from the valley surface.

Interviewer: Benjamin Thompson

These caves, high up in the valley, are made of limestone, and they’re famous for their examples of early human art, such as stencils of hands. In some of the caves, this art has been dated as being potentially 40,000 years old. The cave Adhi and his colleagues were working in is called Liang Tebo.

Interviewee: Adhi Agus Oktaviana

So, in this cave, we have a lot of hand stencils there on the cave wall or on the ceiling.

Interviewer: Benjamin Thompson

To learn more about the people who might have lived in this area around the time these artworks were made, the team set about excavating the Liang Tebo cave, looking for archaeological evidence of human habitation – things like stone artefacts and so on. And they found them, says Tim Maloney, another member of the team, also from Griffith University. But they also found something more.

Interviewee: Tim Maloney

At close to a metre down, we uncovered a very well-defined deliberate burial with stone burial markers and with brightly coloured red ochre or earth pigment grave goods. Within that grave, the individual, they were likely in their early 20s when they died. The skeletal signatures of sex aren't quite distinct so we can't say whether they were male or female. We can say they likely died around 31,000 years before present.

Interviewer: Benjamin Thompson

Finds like this are exceptionally rare, but something else caught their attention as they uncovered the skeleton.

Interviewee: Tim Maloney

During that process, it was quite clear that the lower left leg was completely absent, and then the tibia and fibula had some really unusual bony growth. The opposite right leg, all 26 foot bones were perfectly articulate. And at the time, having answered through the excavation process, where is the left foot – not here being the answer – the next question is what happened? And that's a question that needs to be answered by a paleopathologist.

Interviewer: Benjamin Thompson

Paleopathologists study diseases and injuries in long-dead human and animal remains.

Interviewee: Tim Maloney

We were able to get a colleague to inspect and confirm our suspicions that that unusual bony growth is a very compelling match for clinical examples of amputation surgery.

Interviewer: Benjamin Thompson

Tim says that this pattern of this unusual bony growth is different from what might be seen if the foot had been lost as a result of something like an animal bite, say, suggesting that precise cutting – deliberate amputation – is the most likely explanation. And what’s more, the fact that any extra growth was seen on the leg bones at all shows that the person must have survived having their foot removed.

Interviewee: Tim Maloney

Based on clinical comparison, a minimum of 6-9 years of healing has occurred, which means that between 6-9 years prior to their death in their early 20s is when this occurred. So, somewhere potentially in the order of 10-14, perhaps that age bracket is when they had the amputation surgery. We cannot say what caused an injury to encourage or require that procedure. However, it does imply that the people that conducted it clearly had mastered a range of complexities associated with it, but they were also aware of the importance of conducting it.

Interviewer: Benjamin Thompson

Amputation is complex and, in addition to a detailed knowledge of anatomy, its success in modern times is largely thanks to antiseptics and antimicrobials that prevent deadly infection. But even though this surgery was performed thousands of years ago, the team found no evidence of infection at the amputation site. It’s difficult to know why, but Tim thinks where the person lived may have played a key role.

Interviewee: Tim Maloney

This is occurring not only in an area of this amazing rock art, but it's part of the Earth's tropics, which is also home to, today and very likely when this individual lived, some of the highest biological diversity on planet Earth. The plant diversity harbours a great many botanical resources with antiseptic and antimicrobial properties, supports the case that the surgeons probably had a good grasp of botanical resources to support this successful surgery.

Interviewer: Benjamin Thompson

Tim says his colleagues are looking at things like seeds and charcoal samples uncovered at the site to see what they might reveal about any plants used to prevent infection. They’re also looking for evidence of what sort of tool might have been used to remove the foot. Charlotte Roberts, an archaeologist from Durham University in the UK, has written a News and Views article about the work. She suggests that the find might mean our presumptions about the origins of surgery might need a bit of a rethink.

Interviewee: Charlotte Roberts

The thing that struck me most was evidence for surgery 31,000 years ago, astounding, really, and to see it in a skeleton, an intentional burial in a cave. I mean, it's really quite rare in my field to see direct evidence for treatment of disease or injury. It’s so long ago that it challenges the view that medicine was really late in coming to societies. Everyone thinks it really developed when people started to farm and live in settled communities, but this just challenges that idea we have this assumption.

Interviewer: Benjamin Thompson

Charlotte suggests that the fact that this surgery happened, and that the person receiving it lived for several years afterwards, provides some insights into the communities living in this area at the time.

Interviewee: Charlotte Roberts

Whatever they were treating this person for with that amputation, they felt they needed to intervene. And it just really indicates that they were a caring society because they cared for that person during their life, and they cared for them when they died and carefully buried this individual in a cave. And that, for me, just shows that care has been with us in our societies way back 31,000 years ago up to the present day.

Interviewer: Benjamin Thompson

Quite what form this post-surgery care looked like is something that Charlotte is interested to know. There's another question too. Was this a one-off event or were practices like this common in this area? The absence of written records and scarcity of well-preserved skeletal remains makes this difficult to answer right now. Although lots of questions do remain, Adhi, who you heard from at the start, says this find is important, as it sheds new light on what life was like in ancient Borneo and who the people who made the paintings in the cave thousands of years ago may have been.

Interviewee: Adhi Agus Oktaviana

The finding of a skeleton of 31,000 years, it's always amazing because we can understand how a historic people are living, how they survived in the jungle of east Borneo. I think it’s incredible for Indonesian archaeologists. We have the proof of the people who were living with the early art itself.

Interviewer: Benjamin Thompson

That was Adhi Agus Oktaviana there from Griffith University in Australia. You also heard from Tim Maloney also from Griffith University, and Charlotte Roberts from Durham University in the UK. To read the paper and the News and Views article, look out for a link in this week’s show notes.

Host: Nick Petrić Howe

Later in the podcast, we’ll be hearing how the James Webb Space Telescope is improving our understanding of exoplanets. That’s in the Briefing chat. Right now, though, it’s time for the Research Highlights with Shamini Bundell.

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Shamini Bundell

The discovery of mummified skin from young Triassic reptiles may provide hints at the climate that killed them. Around 252 million years ago, at the end of the Permian period, climate change thought to be caused by volcanic eruptions led to the largest mass-extinction event in the Earth's history. While looking for clues as to what the climate was like in the early Triassic just after the mass extinction, researchers uncovered the remains of 170 four-limbed animals in South Africa's Karoo Basin. These were mammal-like reptiles from two species in the genus Lystrosaurus, among the few creatures to survive the cataclysm. Among the tangled remains, the researchers found young Lystrosaurus that had died in clusters around what was once a dry riverbed. Several were found in a spreadeagled position, similar to what's seen in some animals when they collapse from heat exhaustion. Two of the fossils also had what appeared to be mummified skin, which probably formed through rapid drying after death. Together, this evidence points to a mass die-off of young Lystrosaurus owing to heat and water shortages, suggesting that in the aftermath of the Permian extinction, the Triassic climate underwent periods of drought. Read that research in full in Palaeogeography, Palaeoclimatology, Palaeoecology.

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Shamini Bundell

Mapping avalanche risk in remote mountain regions has just become a little easier thanks to old satellite data. Snow avalanches kill dozens of people each year. They can also block mountain roads, cutting off key routes for transporting food, energy and medicine. Many studies of avalanche risk have been done in wealthy countries or using resource-intensive techniques. But this team of researchers wanted to build a simple way to forecast avalanche risk in remote areas with limited internet connections. To do this, they compiled a collection of satellite images of northeastern Afghanistan taken between 1990 and 2021. By mapping snow patches which remained on the ground late into melt season, the scientists could identify places where avalanches had occurred, even if nobody had noticed them at the time. This allowed them to identify areas at risk, as well as a changing trend in the location of avalanches in the area they studied. The authors say they designed their Snow Avalanche Frequency Estimation or SAFE to help local planners to prioritise their efforts to mitigate avalanches. Read that research in full in The Cryosphere.

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Host: Nick Petrić Howe

Finally on the show, it’s time for the Briefing chat, where we discuss a couple of articles that have been featured in the Nature Briefing. Ben, what have you got for us to discuss this time?

Host: Benjamin Thompson

Well, I’ve been reading an article in Nature that’s looking at the ongoing flooding in Pakistan, and why these floods have been so extreme this year – the worst this century, in fact.

Host: Nick Petrić Howe

Yeah, I've certainly heard about these. They've made headlines across the world. So, I guess, take me from the start. What's going on here? What's happened with these floods?

Host: Benjamin Thompson

Well, let's give some context here then, Nick. So, currently, at least a third of the country is underwater. Thirty-three million people have been displaced, and more than 1,200 people have been killed and, of course, our thoughts go out to everyone who has been affected by these events. And researchers have been looking at what factors have been contributing to these floods being quite so devastating. And it seems like one of the main factors is likely the extreme heatwaves the country has been experiencing this year, and extreme heat is something we talked about on the podcast a few weeks ago. And in Pakistan, between April and May, temperatures were over 40 °C for prolonged periods in many places. And on one day, one city recorded temperatures over 50 °C.

Host: Nick Petrić Howe

Now, obviously, when I think of heatwaves, they are huge issues, but I don't immediately understand like how that leads to flooding. So, why do the hotter temperatures lead to this sort of flooding?

Host: Benjamin Thompson

Well, warmer air can actually hold more moisture, and meteorologists warned that the extreme temperatures would probably result in ‘above normal’ levels of rain during the monsoon season, which runs from July to September. But there are other things at play here as well, Nick. So, researchers are saying that the intense heat also looks to have melted glaciers in northern mountainous regions, increasing water flowing into the Indus river, which runs the length of the country. It's not necessarily clear yet how much water, but certainly another factor at play. And also, the heatwaves have actually coincided with an area of intense low pressure, which has brought intense rain to coastal provinces. So, there's a lot of unusual factors here, and this all has been exacerbated by the early arrival of the monsoon period. So, the effects of it all is that Pakistan has received three times its average annual rainfall for the monsoon period so far, and some provinces have had five times that average.

Host: Nick Petrić Howe

So, obviously, there are these huge floods. What sort of effects are these floods and this huge amount of rainfall having on the country?

Host: Benjamin Thompson

Yeah, I mean, I think ‘catastrophic’, Nick, is the right word to use. So, 1.2 million houses, 5,000 kilometres of road, 240 bridges destroyed, and some researchers are saying that the worst might not be over. For example, some weather agencies have also predicted that the ongoing La Niña climate event, which is often associated with stronger monsoon conditions, may continue until the end of the year, bringing further strong rainfall.

Host: Nick Petrić Howe

And whenever I hear about extreme weather these days, my first thought is climate change.

Host: Benjamin Thompson

Yeah, the intensity and frequency of extreme events is very much associated with climate change, and climate models suggest that more intense rainfall will happen in a warmer world. And research has shown that between 1986 and 2015, temperatures in Pakistan rose by 0.3 °C per decade – higher than the global average. But researchers and public officials are also saying that other factors are probably at play here as well, such as an ineffective early-warning system for floods, poor disaster management, and a lack of drainage and storage infrastructure. So, there's an awful lot going on here and, as I said, our thoughts go out to everyone affected by the ongoing floods. But let's move on with the show this week, Nick, and what have you brought for this week's Briefing chat?

Host: Nick Petrić Howe

Well, this week, I've been reading a couple of articles in Nature, that are about the James Webb Space Telescope’s efforts over the past couple of weeks to look at exoplanets and figure out what's going on with them.

Host: Benjamin Thompson

Yeah, so exoplanets then – these planets orbiting distant stars – are something we've covered on the podcast a few times, and it’s something that I'm very excited about in general. But what's the James Webb Telescope telling us about them in this instance?

Host: Nick Petrić Howe

Yeah, so one of the aims of the James Webb Space Telescope was to look at exoplanets, and it is now kind of exciting to see what it's able to do. So, in the first of these studies that I wanted to discuss, it was actually taking an image of an exoplanet, and that's pretty interesting because it's able to do it in a way that other telescopes haven't been able to do before. So, normally, when you're looking at exoplanets, the star’s light can sort of blow out the planet and you're not able to see it in much detail. But the James Webb has got infrared sensors, so it’s able to take these pictures in infrared, and that basically ramps up the contrast between the star and the planet, so you're able to get a better image of the planet. So, yeah, the James Webb has taken a picture, which to me looks like a couple of pixels but scientists were very excited about, of this exoplanet with the fun name HIP 65426 b, that they say is similar to Jupiter but hotter and younger.

Host: Benjamin Thompson

Right, okay, and why is taking a picture of a hot young Jupiter in infrared quite so exciting then?

Host: Nick Petrić Howe

Well, it’s exciting because it shows what the James Webb Space Telescope can do. And by using this sort of deep infrared, you can actually get an understanding of what the planet is made of and really get to some of the answers that scientists have been trying to figure out about exoplanets for a long time. Which brings me on to the second story that was in Nature, and this was about an exoplanet that was spotted that had carbon dioxide on it, which is the first time that's been seen on an exoplanet.

Host: Benjamin Thompson

Right, so, I know that looking at the atmospheres of exoplanets is something that researchers are super interested in and are very keen to do in high detail, and is finding CO₂ then quite an exciting thing?

Host: Nick Petrić Howe

It is exciting because this exoplanet, which also has a fun name, WASP-39b, it's been looked at in the past using different telescopes, and there have been hints of carbon dioxide but it's never been conclusive. But now, with this new data coming from James Webb, it seems like there's a really nice peak on the graph that they have that shows that there's CO₂ present there.

Host: Benjamin Thompson

And what's kind of the broader context of this then, Nick?

Host: Nick Petrić Howe

Well, it’s boosted confidence that James Webb will be really useful for exoplanet studies. And also, carbon dioxide is one of the components could be a sign of life. It will actually be a mix of carbon dioxide and methane that would be quite a good sign of life, and this is just one part of that, so it's just the carbon dioxide part of that. And now scientists have seen that there is this carbon dioxide here, they can start to come up with ideas and theories as to why it’s there because you would think that a planet like this – a planet similar to Jupiter – would have a similar composition to the star it is orbiting, but that's not the case for this planet and it's also not the case in our own Solar System. So, now, scientists can start to figure out why, and they’ve got a couple of ideas.

Host: Benjamin Thompson

Well, you've teased us there, Nick. Pray tell, what are these two ideas?

Host: Nick Petrić Howe

Well, one is that during the early formation of this planet, it was hit by a lot of comets and asteroids that had certain elements in them that then led to sort of CO₂ in the atmosphere. And that would be interesting because it would be similar to what scientists think when Saturn was in its early formation. The other one is that maybe it formed from materials in the colder outer reaches of that particular system and then migrated closer to the star. And then when it got close to the stars, some of the different elements were blasted off, which would have concentrated heavier elements and then led to more CO₂ in the atmosphere.

Host: Benjamin Thompson

So, it seems like there's questions then about the origin story of this CO₂, but the fact that researchers can now think about answering these questions with the telescope must be quite exciting for them.

Host: Nick Petrić Howe

Yeah, the researchers interviewed for the articles were really excited about these findings because it really shows what James Webb can do.

Host: Benjamin Thompson

Well, Nick, I'm sure we'll be talking about a lot of science that comes from the James Webb Space Telescope in the forthcoming months and years. But for the time being, let's leave it there for this week's Briefing chat. And listeners, for more on those stories, and where you can sign up for the Nature Briefing, look out for links in this week's show notes.

Host: Nick Petrić Howe

And that's all for this week's podcast. But as always, you can reach out to us on Twitter – we’re @NaturePodcast. Or you can send us an email to podcast@nature.com. I’m Nick Petrić Howe.

Host: Benjamin Thompson

And I’m Benjamin Thompson. Thanks for listening.