The First Trees & what they teach us -Dr Sandy Hetherington

Summary

In this episode of Tree Lady Talks, Dr. Sandy Hetherington, a Plant Evolutionary Biologist, discusses the origins and evolution of plants on Earth. The conversation explores the transition of plants from water to land, the characteristics of early land plants, and the development of root systems. Dr. Hetherington shares insights from fossil records, highlighting the complexity of early ecosystems and the symbiotic relationships between plants and fungi. The discussion also delves into the anatomical features of ancient trees and their adaptations to their environments, providing a fascinating look at the history of plant life on Earth. In this engaging conversation, Dr. Sandy Hetherington discusses the evolution of plants, focusing on roots, mycorrhizae, and Fibonacci spirals. The dialogue explores prehistoric trees, their ecosystems, and the lessons we can learn from plant evolution to address contemporary climate challenges. Additionally, the potential for growing plants on Mars is examined, highlighting the intersection of paleobiology and future space exploration.

Takeaways

The first land plants evolved from aquatic ancestors.
Early plants were tiny and unfamiliar compared to modern plants.
Fossilized spores provide evidence of early plant life.
The Devonian period saw significant plant diversification.
Roots in early plants were not distinct from above-ground parts.
Photosynthesis likely began with the earliest land plants.
Symbiotic relationships with fungi were present in early ecosystems.
Ancient trees had unique structural adaptations for support.
The evolution of roots is complex and still debated.
Fossil evidence reveals insights into ancient plant anatomy. Roots evolved as a protective mechanism for early plants.
Mycorrhizae fungi have a long evolutionary history with plants.
Fibonacci spirals are prevalent in nature and plants.
Early plants had different adaptations compared to modern species.
The fossil record provides insights into plant resilience during climate changes.
Plant roots play a crucial role in soil stabilization.
Lessons from the Carboniferous period can inform modern carbon sequestration efforts.
Research on plant growth in space is ongoing and vital for Mars colonization.
Understanding ancient ecosystems can help us predict future ecological responses.
The intersection of paleobiology and modern science can inspire innovative solutions. 

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Transcript

Sharon (00:01.966)
Well, welcome to this week's episode of Tree Lady Talks. Now, I've often wondered, where did it all begin? Where did the first trees grow? What did they look like and how on did it start? So I was delighted when I was watching Earth on the BBC in the UK with Chris Packham and I was enthralled by today's guest who really showed me how it all started and I thought, I've just got to know more and I know that you listeners

be interested because you love a bit of nerdy science. So I'm delighted today to be with Dr Sandy Hetherington who is a Plant Evolutionary Biologist from amongst many other things the Hetherington Institute. Sandy thanks so much for joining us.

Sandy Hetherington (00:50.136)
Thank very much for having me on the podcast, it a real pleasure to be here.

Sharon (00:52.944)
Thank you. So Sandy, tell us a little bit about your academic work, please.

Sandy Hetherington (00:59.148)
Yeah, so really the real goal of our research is to try and understand the early steps in plant evolution. So I think the big questions that get me really excited are when did plants evolve and how did they transform the earth from a kind of barren rocky world, know, a wilderness like that to the kind of lush forested ecosystems that we know today. And so to try and investigate those questions, we combine looking at evidence from the fossil record with the diversity of living plants alive today.

to to try and piece together some of those big questions early in plant evolution.

Sharon (01:33.168)
It's a great detective and deduction process based on science. let's go back literally in the midst of time to hundreds of millions of years ago in the Earth's history. How did the first plants arrive on Earth?

Sandy Hetherington (01:52.738)
Yeah, so we know that the first land plants, the ones that would then give rise to all the flowering plants, the trees today, we know that they started life in the water. So their ancestors were aquatic. And the first thing to note is they were aquatic, but living in freshwater. So often we think of things coming out of the sea, but actually there was a transition first to life in freshwater. similar to some of the kind of algae you might see growing in a pond today. And it's from an ancestor like that, that at

some point roughly around 475 million years ago, an ancestor which lived in the water made this really important transition onto land. And that's really the starting place for land plant evolution, this initial transition to land. And that was the start of what was then going to be this amazing diversity of plants alive today.

Sharon (02:45.392)
So a sort of soup of plants, plant cells, lapped up against a rocky shore and sort of clung on. I'm just going to turn the heat on.

a soup of plant cells lapped up against a rocky shore and sort of took hold on basically rock. Rock, guess, which is weathered by rain and ice. So it must have been a sort of gradual weathering down by sort of lichens and mosses and things. What do we know about what those very early plant-like structures look like?

Sandy Hetherington (03:26.766)
So that's a really good question and one that scientists like myself and other what we call paleobotanists, so people studying fossil plants, are really interested to try and find out. Now, in many cases, the fossil record only gives us some really kind of small fragmentary clues. And during the very early time during plant evolution, we don't have that much information. So just to give a little bit of background for this, the very first kind of signs of life that we have on land of plants are evidence from

fossilized spores, so the reproductive parts of plants, similar to pollen today. These things blow everywhere and therefore they're more likely to get into the fossil record. So we know that they were there at this period of time I mentioned earlier, roughly 475 million years ago. But we really have to wait for about another 40 million years until we actually see the types of plants that were making those spores. So when asked, you know, what did those first plants look like?

Sharon (04:01.136)
Mm-hmm.

Sandy Hetherington (04:22.584)
I think the first thing to say is we don't really know and we had to wait quite a long time. But when we first find them, we find that many of these plants are tiny. They are absolutely minuscule in size and I think would look very, very unfamiliar to what kind of plants we're familiar with today. So one of these types of plants is known as Cooksonia and these things are the size of a kind of pinhead. So they're absolutely tiny. To investigate them, we often have to look at them under a

Sharon (04:48.08)
Wow.

Sandy Hetherington (04:52.438)
a high-powered microscope and we can just see these tiny little branching stems and it's hard to picture a world that was covered in these little tiny branching stems as you said that were most likely quite reliant on water so growing in these ecosystems surrounding by ponds and kind of boggy areas and they were just beginning to take hold really.

Sharon (05:13.808)
How exciting. And so I'm going to ask a series of really daft questions. OK, I might be a bit cunk on Britain here, which is a well-known comedy show in the UK. But so when you find these tiny little spores in the fossils, I'm guessing that you know how long ago that was by the age of the rock.

Sandy Hetherington (05:35.682)
Yep, precisely. So it's the age of the rock and we can use isotope dating to actually get an idea exactly how old those rocks are. So we kind of use a combination of these things to really begin to pinpoint in time how old the things were. So we get a feeling from the rock in terms of what other organisms were present in the rock as well. yeah, fortunately some of these isotopic dates allow us to go back millions of years and therefore

to have this confidence that these things really were incredibly ancient.

Sharon (06:12.058)
Wow, how exciting. And when you found these first plants that were washing up against the shore in my simple mind, did you find any evidence of fungi? But there are two things coexisting straight away.

Sandy Hetherington (06:23.352)
Yes, it is.

And yeah, I think this is one of the most exciting findings from these early early fossils. So there's a variety of these early fossils I mentioned that are really tiny and we just have fragmentary remains. But there's one very special site which is based not too far from where I am up in up in Edinburgh. So it's actually a bit closer towards Aberdeen and the site is called the Rhyney Church and it's named after this small village of Rhyney.

Sharon (06:49.078)
yeah

Sandy Hetherington (06:52.492)
And what's so special about that site is it has this exceptional level of preservation. And that means that not only do we get the plants, we get the entire ecosystem. And just like you say, one of the key things from the ecosystem is the presence of fungi. They are there, they're ubiquitous, and they are forming these symbiotic relationships with the plants at this incredibly early time. And what's quite nice as well is it's not just the direct evidence from the fossils that reveals that this

is a really ancient symbiosis. Actually the genes in living species today and the interactions we find in living species today also hint that it must have been an incredibly ancient symbiosis with fungi going back all the way to the beginning. you know plants have been on land but they've been doing it with fungi for the whole time really.

Sharon (07:40.432)
fantastic I absolutely love that and listeners don't just be listeners be viewers too because we're on YouTube tree lady talks and this conversation is going to be peppered with images to take you back literally in the midst of time and what I really love about these sort of conversations and exploration about the early world is that it's sort of leap forward casually 40 million years I mean

Hang on a minute, let's think back to next Thursday, what did you have for dinner? I mean, these sort of time scales are just extraordinary. Now on the screen, we're gonna show an infographic now, which shows how this first period, which I can't pronounce Sandy, something like, go on, you say it. Slowly, okay. Gently merges into the Devonian period. Let's talk.

Sandy Hetherington (08:11.362)
Ha ha ha.

Sandy Hetherington (08:26.969)
The

Sharon (08:36.208)
timescales for listeners now. When did the first period end and when did the Devonian period start and how long did it last?

Sandy Hetherington (08:46.156)
Yeah, so really what we're looking at is a period of time roughly around 430 million years is a really important switch between the two. And off top of my head, I would need to triple check about exactly the dates of the Silurian, but once we get into the Devonian around that point in time, that then goes on to 360 million years ago. So the Devonian is a reasonable block of time and a huge amount of things are happening in this junk of time too.

Sharon (09:15.77)
Fantastic. And on the infographic, there's a really neat line which shows ground level and it shows the increasing soil depth. tell me how the first soils developed from the first period going into the early Devonian and how different was it by the end of the Devonian period?

Sandy Hetherington (09:36.662)
Yeah, so I think one of the most fascinating things about this period of time is not just that plants are getting complex, but just like you say, soil is getting complex and therefore it's producing this whole extra ecosystem for life below ground. And so what we picture is that during the Siloamian period and earlier in Earth history, there must have been some life on land, but it really was something which we'd call, you know...

microbial mat or a kind of crust, kind of lichen crust that you see on rocks today, know, really clinging onto the hard bits of bare rock or kind of gradually covering up, you know, sandy layers of sediment. But this is all about the change as we move into the early Devonian period. So what we're seeing is that plants are expanding, they're expanding around river systems and where they're growing, they're actually able to stabilize the soil and actually able to actually produce

and maintain larger levels of sediment.

Sharon (10:34.0)
Fantastic. So when we're seeing lichens on a gravestone on a granite boulders in Devon, for example, in Dartmoor, you know, they are some of our oldest living plant forms in the world or relatives of.

Sandy Hetherington (10:49.966)
So, yeah, so lichens are quite a fascinating symbiosis between a fungi and a type of cyanobacteria. in some ways, they're very, very, very anciently related to plants, but also have this extra addition of a fungal symbiosis as well. So they're a very, very unusual organism in that sense. It's two things working together and they're very, yeah, very unusual, but forming these kind of crust.

truss-like surfaces of things which look really definitely very different to many of the types of things we see around us. you're completely right, often surrounding them you'll often find these small moss-like, know, mosses just hanging onto the edge of those bare rocks as well. Whereas the mosses are definitely land plants and they're, you know, much more closely related than lichens are.

Sharon (11:44.788)
So in this time where plants are beginning to evolve, we know as tree people and as nature lovers, they need roots. And I understand a great deal of your work has been about early root development. So let's go back to the very first roots that you found in fossils. What were they like?

Sandy Hetherington (12:09.038)
Yeah, that's a really good question. the earliest roots we find, in many ways, I don't think we'd even recognise them as a root. So what we find is that the earliest plants don't have a really good distinction between the above ground and below ground parts. The above ground parts, for example, they don't have leaves. They were just little twigs, really. And the parts of the plant that was carrying out the rooting function, so the root, as we call them,

were just made up of this massive little hair-like cells that helped them cling to the surface environment. And I think as an analogy, the closest thing we could see to that today are in plants like moss. So although moss will often look like a little green fuzzy ball, if you look at it under the microscope, the reason why it's able to grow on a gravestone, grow on the kind of torsion dart more is because they've got a mass of these little cells that are actually really sticking it and anchoring it to the rock.

The earliest rooting systems we find are masses of those little hairs connected to these twig-like stems. And that was what was enabling them to begin to survive.

Sharon (13:18.436)
Before we move on to how they evolve further, mean, those very first plants, those twig-like plants, when you've looked at them under a really powerful microscope on a fossil, can you find things like chloroplasts? I mean, were they photosynthesising?

Sandy Hetherington (13:34.466)
Yeah, so sadly the actual intercellular structures like chloroplasts sadly don't survive that far back, which is a bit of a shame. However, we can make the prediction that they were that they were photosynthesizing. And the way we can do that is by making a comparison between all the living plants alive today. And we know that the vast, vast, vast majority of them develop chloroplasts that look broadly similar and were photosynthesizing. And if they all do it today, the most likely explanation is that that

common ancestor that lived all the way back then, you know, 400 million years ago was likely doing something similar. So although we don't have the direct evidence for that, we know that that's really suggestive based on living species. And then the other line of evidence that makes us think that they are photosynthesizing is that plants need structures called stomata, which are the small little pores on the leaves that enable them to exchange gas with the environment. Now, stomata have

are wonderful at taking gas but they also cause this problem which is they enable plants to dry out. And so in many ways there'd be no reason for them for early plants to have these stomata if they weren't using them as a way to exchange gas for photosynthesis. So this is a quite nice structural characteristic that can be fossilized which again gives us some indirect evidence that they must have been photosynthesizing.

Sharon (14:56.794)
How brilliant, because we know that plants don't grow things they don't need. There's always a reason. There's a reason for everything. So through that deduction, you can say it's almost certain that they were photosynthesizing. And so that is the first evidence of organisms on the earth using the sun as power and capturing carbon. That's pretty awesome, isn't it? So as we move on to

Sandy Hetherington (15:02.232)
Yeah, that's true.

Sharon (15:26.704)
plant development. There's obviously a relationship between what's going on underground and what's growing up above ground. Let's talk about first of all, as we're in a very early Devonian period, what did the first slightly larger plants look like? How would you describe them comparable to something today?

Sandy Hetherington (15:48.738)
Yeah, so I think the first, during the early Devonian, for me is the first time I think we'd all stand there and say, that looks like a plant. We've seen the first thing that had leaves, we're seeing complex rooting systems and they look broadly quite similar to the living group of plants today known as club mosses. So club mosses are a group of plants that you might have easily never noticed before or have spotted once or twice on a walk and

Sharon (15:56.879)
Yeah.

Sandy Hetherington (16:17.606)
wondered what they are. They sometimes look quite similar to other types of mosses. However, they have this really long evolutionary history. And so some of the earliest club mosses that we can find in the early Devonian are the first plants that we can find that they've got really characteristic leaves, they have these underground rooting systems, they have a sprawling havoc. You can picture them kind of spreading over the surface, some bits growing up towards the light, other bits growing down into the soil. And so I think they would be some of the first that

we'd definitely say yes that looks like a plan and it looks like a plan I could identify to a modern group.

Sharon (16:53.818)
Fantastic. And then as it got larger, I mean, if I want to kind of use the word fun, would that be fair? So how do we go on from there?

Sandy Hetherington (17:00.674)
Yep, yep, absolutely, yeah. Yeah, absolutely. So what we're getting first, and we call this when we're thinking about the kind of the family tree of plants that we can see and we can identify these in the modern plants today. We have group at the base, is the things like the mosses, and then we have a branch called the club mosses. Next to them is the ferns. And so at this point,

Sharon (17:20.896)
Mm-hmm. Yeah.

Sandy Hetherington (17:25.822)
in the fossil record we begin to see these in an iterative way so we find the club mosses first and then we find these early fern light plants and they are popping up at just the same time that the ancestors of the seed plants are appearing. The seed plants are interesting because they today are the vast vast vast majority of trees and so this group of plants is the first group of plants that I think would have been these big woody trees that would be again look so familiar they'd have so many to those same forms and growth.

patterns that we're familiar with seeing today, they would have been there from the period known as the mid-divonian, roughly 380 million years ago.

Sharon (18:05.368)
Wow and I heard and read in your work that some plants that we find today that are just a metre or so tall got up to like 50 metres. So what was better then for the plants that isn't so good now?

Sandy Hetherington (18:23.31)
That's a really good question. It's really hard sometimes to say and you'll hear lots of evolutionary biologists and things. We're often shy away from ever saying exactly what it was because we never, often we don't know what the triggers were for why certain things got bigger or went extinct at certain times. But what's definitely true is like you said, there's a number of species that became trees that are no longer trees today. So we're familiar with tree ferns, but actually in the past there was many different lineages of ferns that were tree sized.

today that they're quite a small number. there is groups like the horsetails. You might be used to seeing these in these wet, boggy environments. They could reach about 20 meters tall or so. You have these giant, thick, woody trunks. And another one called the club moss, as I mentioned to you earlier. One of the groups known as the isoetales. This is a group of plants that, again, I find absolutely fascinating, but most people will have never heard of. But again, in the past,

Sharon (18:59.312)
Yeah.

Sharon (19:07.92)
Wow.

Sharon (19:19.044)
Yeah.

Sandy Hetherington (19:23.086)
they reached these colossal sizes of about 50 meters and they were nicknamed the scale trees because their bark looks scaly which is where all the leaves on the outside of the bark used to be. And so we don't know exactly why they became so huge. We know they were well adapted to wet environments, know, the kind of iconic coal swamp forest, these very swampy settings and these plants just thrived in that environment. But yeah, how...

Sharon (19:31.183)
Yeah.

Sharon (19:45.456)
Yeah.

Sandy Hetherington (19:52.616)
and why they got so big is a bit of a mystery but what's interesting is they are still alive today just as these tiny, the relatives of them are still alive today but just as species that are really tiny in size.

Sharon (20:03.318)
fantastic. wonder, I mean obviously there weren't the predators, you know, the animal predators at that time and also they were just hugely successful in that ecological niche, in that particular climate, in that particular period of time. When I say period of time, I'm talking millions of years, aren't I? It's just awesome. It's just awesome.

Sandy Hetherington (20:25.25)
Yes, yeah, that's the other thing to imagine. It is, yeah.

Sharon (20:30.544)
I mean, what do we know from fossil records about the structure of the trunk from a cellular level? appreciate you can't look at chloroplasts, et cetera, but do we know about, you know, were they very lignin heavy? Were they very cellulose heavy? Was it similar to say a deciduous tree currently growing? Do you know anything about that?

Sandy Hetherington (20:54.67)
Yeah, we do. So we know quite a bit about the anatomy and that's because occasionally we get these fossils preserved with exceptional preservation. And so most fossils you'll see, lots of them are in museums, they'll be that black, coli colour and that's really the only remains of the organic material that was there. So they give us a great understanding of what size and shape these things got to, but not necessarily what the internal structure was. But there's other fossils and we're very lucky to work on a few of these in the lab.

Sites of exceptional preservation that give us an insight into the internal tissues, the structures, and what I find fascinating is especially amongst these different groups of trees, there's been many different types of habits and anatomies that have actually supported those trees. So if you think, let's take the giant horse tails, they're one of my favorites that grew to these giant sizes.

Sharon (21:42.392)
Yeah, I think we can all see those can't we listeners, you know, in your head? Yeah, so that was a giant millions and millions and millions of years ago. Wow.

Sandy Hetherington (21:46.797)
Yeah.

Sandy Hetherington (21:50.414)
I

exactly a giant and what's interesting about it is similar to their anatomy today, at the centre was just largely a very large airspace. So I think for comparison, it's like thinking about a giant bamboo plants today, but on an even bigger scale. So it's interesting to think that was one approach that was used. For those giant scale trees, the ones that have the little tiny relatives today, they were fascinating as well because they actually only made a tiny amount of wood.

Sharon (22:02.032)
Mm-hmm.

Sharon (22:06.286)
Yeah.

Sharon (22:16.538)
Yeah.

Sandy Hetherington (22:22.476)
So a 50 meter tree, but the amount of wood they made in their stems was about this size, despite the fact the whole trunk could be a couple of meters across. it's amazing to think. Yeah, so the main thing was, just like you're saying, it had these incredibly fibrous leaf bases on the outside. So the trunk itself was composed of a very, very thin core of wood, but then on the outside, these really tough leaf bases.

Sharon (22:31.226)
Wow, what was it?

Sandy Hetherington (22:50.594)
that's how they gave the majority of their structural support. I think, again, the best comparison would be maybe things like palm trees, some of the monoclots which get big, but it's hard to imagine a truly giant like this without having lots of wood in the center of it.

Sharon (22:58.469)
Yeah.

Sharon (23:07.098)
So going back to the ones that hollow, that's a fantastic evolutionary success, successful technique because it's going to flex in the wind. It's going to be strong. It's not going to be too heavy. And we see that with our ancient and veteran trees as trees age and get shorter and fatter and squatter and hollow. And part of that is evolution adapting to the longevity of those species, thinking of oaks, for example.

Sandy Hetherington (23:28.76)
Yeah.

Sharon (23:36.558)
But this is about getting the impression of a load of really fast growing, optimum environment species. Do we have any sense of how long they may have lived, an individual? mean, were they tree wings and how long was their life?

Sandy Hetherington (23:57.666)
That's a really good question and one which can be actually quite difficult to get a handle on. It's actually one of these ones which is quite a fun one because it's quite a lively debate in the scientific field. So there's nothing quite like questions like this to really wind up scientists and get them hot under the collar in terms of discussing them. So there's been two main hypotheses for these giant scale trees. One is that these things shot up. They shot up at a speed which

Sharon (24:03.173)
Yeah.

Sharon (24:08.645)
Yeah.

Sharon (24:14.0)
Sandy Hetherington (24:26.194)
we can almost, it's hard to imagine, you'd have to be comparable with some of the fastest things growing today. But then there's another counter argument which is no, these were slow growing and maybe it took them, you know, 100 or 200 years to reach these colossal sizes. Now the difficulty is just like you said, there's wood and tree rings would give us an answer but because they only have this tiny, tiny wooden cylinder at the centre it's actually very difficult to identify tree rings in the same way we would do in, you know,

And we've got lovely examples of fossil conifers and fossil, you know, linges that are around to today, where we can do that. But in these really old ones, we don't have as much evidence for that. And so then it comes down to trying to think about hypotheses for how do you estimate how fast a tree is growing? Where you say, okay, let's think how many leaves it had, how much could it photosynthesize? that's a kind of really nice thing that we can try and do. But again,

get scientists really hotly debating as to whether these things flew up or grew a bit slower. My feeling, if I was pushed, would have to be to say that they were probably growing a bit slower, slower in the sense that they were not, you know, growing over the course of 100 or 200 years, rather than going up in 30 years. And I think the reason for that is we know that they were growing in these swampy environments where there's not a huge amount of nutrients. And so,

Sharon (25:27.856)
Yeah.

Sandy Hetherington (25:50.194)
you're in an environment with not a huge amount of nutrients, even if you've got lots of light, it would be hard to put on a growth spurt of couple of meters a year for example, whereas it seems like they might have just been a bit slower and taken the time. But again, that is just a guess, so something to investigate more.

Sharon (26:08.342)
us really strong hypotheses because if they were growing in a swampy environment it would be quite anaerobic in terms and we know that tree roots need an aerobic environment in which to foster sorry I've got a cold and which to prosper and but I wonder were you finding pneumatopause these sorts of wonderful elbows that we have like the swamp cypress

taxodium distishum growing. Were they doing the same sort of thing to kind of like get these elbows up there, get a bit of aerobic stuff going?

Sandy Hetherington (26:47.534)
That's a really good question and one we have been hunting for in the fossil record. So what we know is we know that especially these scale trees, yeah, these scale trees, they had a very unusual rooting system. They had a rooting system which, like the main big trunk of the tree, they had big woody roots, but they were also quite largely hollow through quite a lot of their rooting system as well. And so one hypothesis is that actually they were able to transport

Sharon (26:50.895)
Yeah.

Sharon (27:10.192)
Mm-hmm.

Sandy Hetherington (27:15.118)
transport air and gas through that hollow system and that could be one way they might have been able to get air to some of these more inoxic parts. The other hypothesis is that they have these little smaller rootlet-like structures which stick off the side of those big woody bits and perhaps some of them also were involved in either growing into areas with more oxygen or they were able to take up oxygen from bits of the water. So that's an example where we're still unsure.

Sharon (27:29.136)
Yeah.

Sandy Hetherington (27:44.622)
about exactly how they did it but that's one. And then there's a few other species growing those swamps as well and we know that some of them, although we don't have evidence of the kind of yeah, pneumatophores in that sense, what we do find is evidence of root adaptions to these swampy environments. So the kind of prop roots, cluster roots, so basically all of these roots that we find today in trees which really help them stand up in boggy environments. So producing large numbers of roots for

Sharon (27:45.103)
interesting.

Sharon (28:04.387)
Yeah?

Sandy Hetherington (28:14.318)
further up your trunk to really stabilize or to have these quite extensive bases on the trunk to again give them more rigidity. We definitely find air in the fossil record. just like today, these trees were really well adapted to these quite unusual and boggy environments. I'm sure that would have kept them up in the strong wind in that sense.

Sharon (28:35.12)
fantastic. And there's a fantastic image that we'll be showing now of a slice for a fossil showing the central cause of roots being hollow with some little white arrows there. So watchers enjoy those. So I think that I also learned from your studies is this idea about the root caps. So we know that root caps are really useful. They're sort of at the end of a growing root.

and help slough, they sort of slough away as they grow through the soil. Am I right in thinking that some early roots did not have that root cap and that you proved that?

Sandy Hetherington (29:08.994)
Yeah.

Sandy Hetherington (29:16.662)
Yeah, this was a really, really fun, fun bit of work that we took a dive into. So the big question for us was to understand when did roots first evolve and how can we be confident about finding them in the fossil record? Now, part of this sounds a bit like semantics in that, well, obviously you'll find it depending on how you define a root. And so to go about this, we set off with looking at the roots of living species we can see alive today. And as you said,

basically every example we have of living species today with their roots, they all develop from a root tip covered by this protective structure known as the root cap. And so really, to pinpoint the origin of roots, what we really wanted to do was to try and find the earliest evidence for those in the fossil record. So again, we jumped on these sites of exceptional levels of preservation, and we knew that from the Carboniferous period, so roughly 350 million years ago, that sort of time,

when much of the world was covered by these scale trees, by these coal swamp forests, we could find evidence in cases there of roots covered with these root caps. So we knew that roots were present and looking incredibly similar to what they do today at that point in time. But what we wanted to do was to take that further back in time. And this is again with this site I mentioned earlier, the Rhyney Chert, this site with exceptional preservation came into play. And the reason for that is because the plants in the Rhyney Chert

Sharon (30:36.976)
Yeah.

Sandy Hetherington (30:44.756)
the potential to be preserved with exceptional preservation and we had some of these early plants that had the first kind of more complex rooting systems and so in our world what we did is took a really deep dive we went hunting through fossils to try and find evidence of these rooting tips and after a lot of looking in museums there's some wonderful collections in the UK that I went around I also visited collections in Germany which have vast numbers of these fossils

examining them under a microscope, I came across the first evidence of what we thought were the root tips, so the very very tips of the roots, just where we'd expect to find evidence of a root cap. But what was fascinating was despite that exceptional levels of preservation, there was no cap covering these roots. So it seemed to be these things looked very very similar to the roots we know today but not quite there.

Sharon (31:19.748)
Mm-hmm.

Sharon (31:36.368)
So they've evolved to have root caps, do you think? Because it makes the plants more successful. It's like a protective mechanism, isn't it? To take it through what would have been very early soils. You know, I'm just going back a few hundred million years. But it would have been craggy and rocky, I guess. And so not to have those, it'd be ouch constantly, wouldn't it?

Sandy Hetherington (31:39.682)
Yep, exactly, precisely.

Sandy Hetherington (31:50.392)
precisely.

Sandy Hetherington (32:00.526)
It would have been exactly.

Sharon (32:03.288)
Yeah, you're very unscientific language there. Sorry to any deep scientists listening to tree lady talks, but that's great. So while we're on roots, like we are so interested in the fact that there is this teeming ecosystem underground of microfauna and mycorrhizae. I read that in the very earliest plants, there is mycorrhizae fungi on the plant leaf.

Sandy Hetherington (32:07.318)
No, no.

Sharon (32:31.948)
axis, not leaf, branch axis. Am I right in thinking there's a bit of gap in science at the moment? No doubt you would feel in the early Devonian period with mycorrhizae. What do know about the evolution of mycorrhizae fungi in the soil and tree roots as you go through time?

Sandy Hetherington (32:33.784)
Yep. Yep. Yep.

Sandy Hetherington (32:41.346)
You

Sandy Hetherington (32:53.358)
That's a really good question. And again, that wonderful site, the Rhinacher, gives us really nice insight at that point in the early Devonian. It gives us the first direct evidence of macorizal fungus forming that similarity relationship with plants. They're there and they look remarkably similar. Anatomically, they look identical to what we find in living species that form a similar symbiosis today. So they were present, but just like you say, what's kind of unusual is that they're formed not just

in the rooting system, but they're actually formed in quite a lot of areas across the plant itself. So this is unusual in the sense that today, those symbiosis relationships are really focused just on the root. And so a big question is at what point and how do we get the specialization of that fungal symbiosis to only occur in the root? And that, just like you say, is a question which is really ripe for investigating further.

Sharon (33:27.493)
Mm-hmm.

Sandy Hetherington (33:52.14)
We know if we jump forward a few million years when we start seeing trees and tree roots, when we find them well preserved, we find clear evidence of the Arbuscula macrioritae or the AM symbiosis, we find those in those tree roots. And we know that in some of those earliest plants, but you don't have roots that they're present everywhere. So fingers crossed we can find a few more fossils that might help fill in that gap and to begin to understand about what enabled and what kind of facilitated

localisation of those relationships into one place. Now we know there might be a few things contributing to this, we know that the plant might be able to actually interact directly with the fungus and maybe give reason to promote it being in one place or another, and also the plant can also have barriers to stop it moving around, it is a really fascinating question and I think it's one that we certainly need some more work on, just so can find out.

Sharon (34:48.666)
So going back to relationship with trees and fungi generally, they're moving away from just mycorrhizae. Is there evidence in the Typhoonian period or the Carboniferous period? Have I said that right? Yep. Okay. Is there evidence of fungi in a trunk? You say there is evidence of fungi being all over the tree of these wall barriers, the pseudosclerotoplates.

Sandy Hetherington (35:01.666)
Yep, yep, that's exactly right,

Sharon (35:18.032)
Can you find those of where the tree is? Maybe within the tree there's a fungi wall as Professor Limbody, friend of the show, says, you must know Professor Limbody, you know, where one fungi is going, I'm going to get you. And the other one's going, no, I'm going to get you. And then they do like this robot wall in the middle. Can you find that in these records?

Sandy Hetherington (35:24.792)
Mmm.

Sandy Hetherington (35:36.238)
I'm

That's really interesting. I think I haven't looked into those specifically, but absolutely there's definite evidence of, clear evidence of fungi in larger parts of the roots, in smaller rootlets. And there's also definite evidence where you can see that the plants themselves are having a response to some, whether it's a pathogenic fungi and they are throwing up these, know, lignified walls to protect themselves from areas, kind of wound responses, damage responses.

clear evidence on that. And I'm also sure that there must be clear evidence of interaction between fungi and fungi. That'd be a really interesting... I have colleague at the London Natural History Museum called Christine Stuladerian, who's an expert on fossil fungi, and she'd be the person to ask. I think she'd be able to give us a clue there. maybe she would be a good person to ask. Yeah, definitely.

Sharon (36:24.176)
do let her know about this podcast because I would love to talk to her. No, I really, really would. That's amazing. Gosh. So these early roots, similar then in their adaptation process to roots today. I mean, once you get towards the end of the Trevonian period, are they broadly similar to what we see today?

Sandy Hetherington (36:49.25)
Yeah, think that's correct. And there's been some really wonderful work carried out by Bill Stein and colleagues. So this includes Chris Berry at the University of Cardiff. He's done some really amazing work mapping the extent of the rooting systems we find in fossil forests. And there's one very famous fossil forest in New York, in New York state, not right in the middle of New York. And this is a really lovely example where we've got lots and lots of large trees in

Sharon (37:12.58)
Yeah, yeah.

Sandy Hetherington (37:19.116)
in one single place and that gives people a chance to actually map out and see their distribution. And what they found especially in this setting is that amongst the woody trees, which look most similar I'd say to kind conifers today, is that they already had incredibly extensive rooting systems going out quite a few meters, five, six, seven meters out, outwards on either side of these large trunks.

I think in many ways, if I showed you a picture of those, you might just think it looked just like a modern conifer root today. So I think in that sense, many of those adaptations we think of were already present. And it's quite remarkable, isn't it, to think just how long ago these things that we're familiar with today would have also been there, going all the way back to 380 million years ago, to be able to have a similar structure that we kind of be used to seeing today.

Sharon (37:52.078)
Yeah.

Sharon (38:12.24)
I want to say that again, that's 380 million years ago. Wow, we really are a speck. And I read somewhere in your work that the soils we have today are only in the last 10 % of the Earth's history. So just to put that, it sounds almost modern, what we're talking about today. Incredible. The other area of your work that really fascinated me was Fibonacci spirals. What are they?

Sandy Hetherington (38:32.6)
Yeah. Yeah.

Sharon (38:42.338)
and when did they start and why are they great.

Sandy Hetherington (38:45.71)
So, Fibonacci spirals are a spiral pattern that we find in nature. then called Fibonacci after the famous mathematical series, the Fibonacci series. So, that's a famous mathematical series. So, the first question is, what is it, what's it doing occurring in nature? What's it doing occurring in plants? But it just so happens that this sequence, the numbers in the sequence keep cropping up from a variety of different forms that we find around us. And they are particularly common in

particularly common implants. And I think the one thing that I would recommend to people, next time you find a pine cone, if you pick up a pine cone and look at the base of it, your eyes will definitely be drawn to these spiral patterns. And you can do this, you can even mark it on with a pen. You can see the spirals are going either clockwise or anti-clockwise spirals. And if you count up the number of clockwise and anti-clockwise spirals, I can almost guarantee you, because people have done scientific studies on these,

and the number goes up to something like 95 or more percent that when you count the number of clockwise and anti-clockwise spirals, these will be numbers in the Fibonacci series. And so it's quite remarkable to think that this pattern, this famous mathematical pattern is occurring in a way which is so common that we'd all be familiar with seeing today.

Sharon (40:07.29)
I think because we've evolved and it's a really ancient plant evolution, which I think 90 % of plants follow something like that, one way or another in their structure, that we find it really pleasing. We find it beautiful. I think that in many ways that we've evolved to seek solace and beauty in the color green and also in blue, these very natural colors.

There are all these patterns in nature which are shown to have a physiologically pleasing effect on the brain, lowering our blood pressure and making us feel better and releasing beneficial hormones and flooding our system. That these patterns in nature, these colours in nature are inherent to our wellbeing. And I think that's, it's fascinating that you've studied it, but I think there's a bigger thing here about...

our need to be in nature and why these things are intrinsically wonderful. So these have been around for a really long time and tell us about how you looked at the early, early plants, another plant I can't pronounce, and then you made this model. Tell us about that.

Sandy Hetherington (41:06.158)
Yep.

Sandy Hetherington (41:21.858)
Yeah, absolutely. So we were particularly interested in both the origin of leaves and the origin of these famous Fibonacci patterns. So when was the first time we could turn to the fossil record, identify leaves, and attempt to go hunting for these Fibonacci type patterns? And this brings us back to, again, the Rhynie Chert, my favorite fossil site, and to this time a particular plant called Asteropsilon macchi. This is an early...

Sharon (41:45.338)
That's the one, it was on the tip of my tongue!

Sandy Hetherington (41:48.046)
This is an early club moss and this was the one that for me I think is one of the first in the group of plants that you'd first recognize as being a kind of plant and it would look familiar today. So this type of plant, we find it present in the Rhyneychurch, it's been described as having these leaf-like structures so for us we thought this could be the one to investigate further to understand a bit about the origin of leaves and to look for evidence for these famous mathematical spirals.

Now what's special about the Rhynie Chert as I mentioned earlier is its exceptional preservation but with exceptional preservation comes three-dimensional preservation as well. although when you're holding this you're actually typically holding just a solid block of rock, all the plant stems within there are preserved in 3D. And so what's amazing if you make lots of cereal preparations of them, like lots of glass slides through them or a technique called peels which is almost like

putting a little bit of sellotape on and ripping it off and doing that lots of times. Yeah, it's quite an amazing sort of process. But if you do that to the rock, what this gives us is a record that we can then digitally stick back together and actually picture exactly what the plant looked like in 3D. And so this was project carried out by, started off as a master's student in the lab called Holly Ann Turner. And she did a wonderful job. She just had a real eye for aligning these images up on the computer and gradually

Sharon (42:48.004)
Ow.

Sandy Hetherington (43:14.348)
really took a long time to gradually align them all together to draw around them, to trace around the outlines of the leaves. And eventually this gives a 3D model of this shoot system. So she did this and this was the first time we could really look at the arrangement of leaves in a plant from this period of time. And the first thing that jumped out to us was there seemed to be some evidence of spirals. So we thought, well, this is going to be very exciting.

likely to be one the first times we're going to find these Fibonacci type spirals. And so it came as a bit of a surprise to us that after a long time of looking and a long time of us really having to convince ourselves and finding a few more replicates and having to double check again and double check again, we realized that what was unusual about these is they were spirals, but these were non-Fibonacci spirals. So what that means is when you count the number of clockwise and anti-clockwise spirals, they're not numbers in the Fibonacci series. Now,

Sharon (44:01.712)
Sandy Hetherington (44:10.189)
That doesn't mean that they're not, that they still look like a regular pattern, they still are a spiral form. But this is what poses a really interesting question for them being so similar to many living species today and yet so different because these numbers were different. So it was our first real insight that these non-fibonacci patterns are in fact incredibly ancient and therefore these early plants were quite different in some ways to many of the living species we know today.

Sharon (44:40.56)
And you made a 3D model of that, didn't you? And it looks a bit like, you're going to be appalled by this, looks a bit like a cucumber with load of birkins sort of sticking around the outside, imagine cocktail sticks and sort of going round in a sort of vague spiral. that's, isn't it wonderful how all this new technology enables a greater visualization of what things used to be like and what we can learn from that.

Sandy Hetherington (44:44.109)
Yeah.

Sandy Hetherington (44:47.438)
It does, yeah.

Sharon (45:09.796)
Wow, that's amazing.

Sandy Hetherington (45:10.03)
It's really quite special. think the 3D print gave us for first time just a completely unique view on this. Just like you say, the first thing that stuck out is just how quite large in diameter the stem is. Like you said, it looks quite odd. It looks a bit like a cucumber with these small little leaves on the So that in itself was very interesting. And then what was wonderful was to work with a digital artist who helped us actually 3D print it in its actual size. So we printed a kind of larger version so we could...

Sharon (45:25.839)
Yeah.

Yeah.

Sharon (45:38.383)
Yeah?

Sandy Hetherington (45:38.89)
visualize it more but printed to actual size you know we're talking only about a couple of centimeters inside this tiny little scale and you can almost hold that next to their living relatives today and they just look so similar despite there's you know it's a 400 million years of evolution between that and the living club monsters so yeah that was really good fun.

Sharon (45:49.946)
Wow.

Sharon (45:55.344)
So you've been learning about what success looks like in plant evolution. That's absolutely fascinating. I'd like to talk about the future in a moment, but before I do, we have a wonderful community with Tree Lady Talks and I've got some listeners questions here. So I wonder, what prehistoric trees would you like to have seen survive?

Sandy Hetherington (46:08.472)
Yeah.

Sharon (46:23.344)
to the present, clearly some sort of have.

Sandy Hetherington (46:26.574)
Yep, that's a brilliant question. I think it'd have to be those scale trees. They for me are just, I would love to see one in person and to actually, yeah, to be able to really test how quickly they grew and what they look like. What's so special for me about those trees is we find them fossilized and they have a very extensive fossil record. So we actually have good evidence of like fossilized tree stumps. So you can almost, you can stand next to a fossilized tree trunk and picture

what it must have been like just to look up in the air and see this great expanse of a tree growing up. So I think that would be one I would really love to see, love to see just how unusual they looked like when they were growing and just how different they were to most modern trees today.

Sharon (47:14.112)
And if we're not far off with virtual reality and the modeling that we can do now and AI, actually putting on a headset and actually just being in a Devonian period and walking through the forest. my God, I so want to do that. How close are we to doing that?

Sandy Hetherington (47:35.374)
I think we're actually relatively, I think you're right. I think it would be a wonderful project to do. I know people are kind of exploring those sorts of options. as you said, we've been making these little 3D models of these tiny little fragments, but there's no reason you can't make a full ecosystem. We have enough evidence. And so I think it'd be a wonderful thing to actually be able to walk through. then it would be interesting just to think about the other ways you can build on those experiences.

Sharon (47:37.488)
Yeah?

Sharon (47:48.762)
Yeah!

Sandy Hetherington (48:03.414)
to think about what temperature it would have been like. Even trying to imagine what kind of things you'd be able to smell. What would some of these, it wouldn't be like a pine forest, it'd be something different. And how you go about simulating or predicting what this, I think that'd be a wonderful, wonderful project.

Sharon (48:05.103)
Yeah!

Sharon (48:10.469)
Yes!

Sharon (48:18.976)
my God, I so want to go to a Devonian Forest Experience Centre, put on a VR headset, walk through and feel the temperature, maybe the humidity, hear something. What would it be? I wonder what it would sound like. Yeah.

Sandy Hetherington (48:37.376)
maybe some rustling arthropods in the the sort of things that would be amazing, big millipede or something.

Sharon (48:42.222)
Yeah. Wow. God, that would be incredible. actually, sort of scuffing through. mean, the other thing to say is, if I was in that experience center, surely I'd be up to my knees or beyond in sort of decaying matter. I know we had fungi and we would have had lots of insects and things. But I mean, do we have a sense of like how much

leaf litter and stuff was around.

Sandy Hetherington (49:15.234)
Yeah, that's interesting. So I think one example where we can speak to that is typically those coal swamp forests. We know it would have been really swampy and we know they were forming vast, vast, vast amounts of peat, which then eventually, through geological heat and pressure, became coal. And so we know at that point in time, I think it would have been a very boggy, very peaty, very hard to sort of terrain to go in between. And that would have been one example it would have been.

Sharon (49:24.336)
Mm.

Sandy Hetherington (49:43.316)
that, whereas in some of the other ecosystems we just don't know. I mean it's a really nice question to think just about, for example, when did, so we you know we'll begin to think about you know when trees are full, but when was there a distinct understory and a tree? know did in some of these forests we think that there might have just been you know large numbers of these trees close together just growing up in a waterlogged environment, but yeah to have a bit of a think about when you got the distinction between what we, you know what castles and understory growing on those fallen logs.

Sharon (49:56.463)
Yeah.

Sandy Hetherington (50:13.006)
I think is a really, really fascinating question. hope, a few, you occasionally get a fossil which will then, you know, reveal what this would have looked like. But in most cases, we just don't have the evidence.

Sharon (50:23.94)
Well, if you're listening to this and you know somebody who works for one of the huge film studios, okay, and it's great visualising this, but needs to do it properly because we will be offended as scientists if it's not done properly. Could we have like a really fabulous visualisation of this? I'm sorry to be crass, but there's probably money to be made, which is all good for research.

just to experience this, my God, I fancy that. Well, going back to listener questions, this is Matthew Norman and his daughter. And he asks, what were the early pollination strategies that we're aware of?

Sandy Hetherington (50:54.699)
Hehehe

Sandy Hetherington (51:06.018)
Very interesting question. So pollination strategies as we're kind of mainly familiar with them today, most of these ones are from the flowering plants. But in actual fact, the flowering plants are not particularly ancient from a geological point of view. So although they make up the vast majority of species alive today, they've only been around from, they only really saw the very end of the dinosaurs and then they've lasted through when the dinosaurs went out. However,

We know that plants have been on land for 300 million years before that. And so when we're thinking about pollination in most of these plants before then, the vast majority of these are wind pollinated. So it'd be like many sort of conifers today. In the case of the ferns, where plants are producing vast numbers of spores, they're getting blown by the wind. And so there isn't as much direct evidence of many of these kind of pollination strategies we're familiar with in flowering plants. There's a couple of early examples where

The evolution of Beatles was playing a key role in some groups, but in actual fact we predict that in most cases it was just the wind.

Sharon (52:12.986)
Fabulous. So all this fantastic science about the evolution of plants through the history of time. How can we use this science, in your opinion, it may be just hypothesizing, to deal with the problems of today? So we're in a time of quite rapid climate change with extreme weather events. We don't really know how it's going to pan out and different measures that parts of the world will take or not take. But

Through this understanding of how roots have evolved and plants have evolved, might there be something that we can draw upon to make our trees and woody structure plants work harder for us in terms of carbon sequestration, soil stabilisation and also drawing down of nutrients? What are your thoughts on that? It's a bit of a big impossible question. So you can step out of being a true scientist here and just be a...

a chap who's interested.

Sandy Hetherington (53:13.374)
No, it's a wonderful question and it's one that I think about a lot. I think it's really important that the work that we do in the lab, lots of that comes from taxpayer money and one of our key things is to educate, to learn more about the fundamentals of the world, but also to think really what can these fossils tell us that will be able to benefit and be of use to the people of UK, but also people of the world. And actually I think fossils have a really key part to play.

in trying to understand what's likely to happen with changing climate in the future. And the reason for that is the fossil record gives us direct evidence of how plants have survived and able to thrive through really extreme conditions in the past. And so by studying some of these examples in the past, we can actually begin to predict what might happen in the future. Now, sadly, one of the big issues we're facing at the moment is just the

the level and the speed of warming and the speed of change is just unprecedented. So it's hard to know what might happen. But what we can definitely find is clear examples of plant groups in the past that have been able to move. They've traditionally been able to track climate. So you can really see the movement of big plant groups. And we know this is a lot more difficult in today's world because we like to build cities and roads and again, the speed of the warming is so fast that...

plants aren't able to evolve but there's clear evidence in the past of plants being able to do this. This was one way they were able to get around things. We also know that there have been periods of time when many plants have gone extinct. There's been mass extinction events for plants as well as animals but interestingly there's been fewer, fewer of major extinction events for plants. They've been able to weather some pretty tough storms in ways that many, many groups didn't. As I said, know, the flowering plants were

were really taking shape at the time when the dinosaurs went extinct with an asteroid, and yet the plants were able to rebound from these kind of conditions. they're remarkably resilient, and I think studying some of these times in the past can be really informative. I think going to your point about some of the specifics, things that really interest me are examples of these linked with rooting systems. So we know that plant roots have a really key part to play in soil stabilization.

Sandy Hetherington (55:39.518)
can see this on a global level, we know that the origin of plant roots were essential to forming the first soils and I think that again should just be a lesson to us about the importance of maintaining land with plants on and extensive rooting systems today. And also the fossil record can really give some clues to things that might be novel ways of actually thinking and approaching some of these big challenges we're facing today. You know we talked about the carbonifers this period of time when

plants buried vast amounts of carbon, which sadly we've burned today as coal. But it's interesting to think that during the carboniferous, was CO2 in the air. Those plants captured that CO2 from the air and were able to lock that up and bury it. So they've done things like this before and we can be inspired by those. And the other one would be weathering as well. So the origin of plant roots really increased the amount of weathering. So it increased chunks of weathering in certain areas and that in itself drew down CO2.

Sharon (56:19.632)
Mmm.

Sandy Hetherington (56:36.962)
So there's been some really nice initiatives about how we can actually grind up bits of rock and actually put those on fields as well, such as basalt. And the actual weathering of that not only can give some nutrients, in some cases can give some nutrients to plants, but can actually act as a catalyst for drawing down more CO2. So yeah, I think it's a wonderful question. I think it's one that myself and many plant scientists are keen to think about. So I think it's a great one to continue thinking about.

Sharon (56:44.814)
and

Sharon (56:53.444)
Yeah. Wow.

Sharon (57:02.96)
And finally, we've gone back in time and imagine walking through a Devonian forest. I'm now going to fly forward 20 years because Elon Musk is planning to colonize Mars. And Mars is a rocky planet. So we're just having a bit of fun here. But we think they think they found water there in the past and correct me if I'm wrong, but might.

Scientists erroneously or inappropriately or appropriately, I don't know, I don't make any moral judgments on this. And I kind of way beyond my comfort zone and my knowledge in talking about this. But in terms of what we know from evolution of plants, could that scientific knowledge be used to help colonize Mars? And do you know if that's already being thought about in terms of?

the new plant evolution of a planet. What are your thoughts on that?

Sandy Hetherington (58:05.39)
That's a brilliant question. I think it gets people excited and actually it's just quite a nice catalyst to start rethinking about the questions that we spend our day to day thinking about. And so I think the main question where people have thought about quite a lot and have put quite a bit of energy is not necessarily Mars, but it's getting to Mars in the first place. So there's actually a surprisingly large number of studies of plants being grown in space.

Sharon (58:28.335)
Yes.

Sharon (58:34.959)
Okay.

Sandy Hetherington (58:35.278)
to work out what on earth plants do in zero gravity because this is a really good question and some of the difficulties that it calls from that because there's one big advantage I mean if you can have plants happily growing in your spaceship then you've got this lovely supply of oxygen with you there at the time and the prospect of having food. So yes it definitely is an area that people are really interested in in exploring about what yeah

Sharon (58:40.132)
Yeah.

Sharon (58:53.2)
What?

Sandy Hetherington (59:03.352)
how plants do survive in these kind low-gravity environments, what would be the best plants, know, what would be the ideal plant to take up with you? Is it best to think about just having some algae you could keep in some water and control in a very, you know, very set environment or do you have something which is longer growing and can live longer? That's one really good question. And the other thing, again, which scientists are definitely doing is trying to grow plants in rock samples taken from Mars. So...

Sharon (59:31.534)
Wow, I didn't know that.

Sandy Hetherington (59:33.888)
So again, we can either simulate what we think based on the small samples, we can kind of scale up the small rock samples we have to make predictions about what that rocky sandy substrate would actually look like and then just plant plants in it and see how they get on. And then as we get the prospect of getting more more samples back, makes it more likely you can actually have a go at growing them in controlled environments and things. yep.

Scientists always love questions like this and will continue to think about them. I think it's a really exciting, it's a fun avenue to really give the court to give a bit of a different perspective to the day-to-day research we do.

Sharon (01:00:11.376)
Fantastic. So this podcast has been recorded on the 7th of November, 2024, where things have just changed in America and Elon Musk is going to be in a slightly new position. This is a non-political podcast, but I thought it would be fun to explore what might happen next in Mars. And I had no idea. And I'm curious. I want to know more about growing plants on Mars. But Dr. Sandy Hetherington, you?

Sandy Hetherington (01:00:31.469)
you

Sharon (01:00:40.89)
have absolutely shone a light on the mists of time and where we are today. And I like to imagine you going and digging up fossils, driving around different museums, working hard in the lab with your wonderful colleagues, where I'm sure you're a great team, different types of sampling and now modeling so that we, the non-paleobiologist, have a greater understanding of what's happened, why

and how it can help us in the future. Dr. Sandy Hetherington from the Hetherington Institute. Thank you so much for your time and your enthusiasm.

Sandy Hetherington (01:01:21.582)
Thank you very much. It's been a pleasure being on the show.