Uncovering life in the Antarctic Dry Valleys | Craig Cary | TEDxScottBase

My first trip to Antarctica was in 2001, when I was lucky enough to be invited to participate in an expedition to the 6,500 square kilometer McMurdo Dry Valleys. To me, the McMurdo Dry Valleys are the largest permanently ice-free area on the continent. As a microbial ecologist, this was a really exciting opportunity because for the last 30 years I've been studying probably the most extreme environments on the planet and the microbial communities that inhabit them, whether it's the deep-sea hydrothermal vents or the hot springs around the tops. world of active volcanoes or acid mine drainage sites and the reason I do this is because I believe that by understanding how bacteria can operate in extreme environments, we will be able to better understand how they operate in more complex environments and you will be able to see in a moment why I think bacteria are probably the most amazing organisms on the planet.

Now my mom, who is 90 years old, asks me every time I go to see why, of all the beautiful organisms on the planet, I chose to work on something that you can. I don't see that it's something that most people don't really care about. Well I'll give you a few reasons why I think these are such cool organisms, first of all they've been around for 4 billion years and they've survived multiple extinction events and multiple climate change events they're the most diverse organisms on the planet. In fact, we have only been able to cultivate less than 1% of them, they occupy almost every niche on the planet, whether man-made or in the environment, and at the same time, they have the ability to evolve extremely quickly, they evolve in generation times, the record is approximately 10 minutes, they return the ability to escape, they have the ability to acquire our DNA from the neighboring cell from the environment or even from a viral infection which gives them an increased and immediate capacity to adapt to a ever-growing and changing environment that surrounds them.

Also, in my opinion, the master biosensors of the planet, cells are covered in receptors, each of which is capable of detecting various molecules in the environment, so sensitive that a single molecule can cause a change in a response now that response. If we were able to decipher and decode that answer, imagine the power we would have to understand how the environment is operating. I think if we could do that, these would become the most essential sensory sentinels of the environment. Now, when I got to the Dry Valleys in 2001, most of that 30 years of really productive microbiological research had been done there, but most of that work had been done using culture approaches.

We only really knew what we could grow and I was bringing something new to the table thirty years ago there was a huge revolution in technology that was taking place around the world technology very powerful technology was being developed to allow us to unlock hidden messages in the DNA code now, while most of this technology was targeted at human and human-related diseases, microbial ecologists were looking at the power of these tools that we could apply to be able to understand bacteria in the environment, as well What became very evident when they started applying these tools and this was about 25 years ago was that the diversity of bacteria that we thought existed based on these cultivation approaches had greatly underestimated the diversity, which is why these tools are so powerful that now allow microbiologists to better answer these two questions: how do bacteria work?

They interact with each other and how they interact with the environment around them. Four billion years of evolution gives us enormous leverage in terms of environmental interaction if we could dig deeper into this and be able to figure out how these organisms relate to their environment. We could build a capability to be able to sense the environment today and hopefully be able to predict where the environment is going in the future, but to do this we need a functional ecosystem, you can't take the ecosystem out. from the environment and put it in the laboratory, it is too complicated and you will change it, so the microbial ecologists, of course, wanted the first thing they wanted to do was move to complex systems, well, these systems are too complicated for the animals and the plant diversity, bacterial diversity, viral and fungal diversity, all piled on top of the chemical and physical environment, it is too complicated, it is a kind of proverbial forest for the trees, what we are looking for was something much simpler, a place where the complexity of higher level organisms were eliminated and microbiology could stand alongside the physical and chemical environment, so this brought us to the Dry Valleys now, as I mentioned, 30 years of research had been done. and that work had left us with three beliefs: the first was that the system had low biodiversity again, this is using cultivation approaches, the diversity was low because the system is extreme, this is very typical of extreme environments, the selective pressures are so extreme that they are the only organisms that can survive or the ones that are highly adapted to living there, the second is that everything was everywhere, no matter where you went in the dry valley system, you basically grew the same and third place, due to the temperature inside.

In Antarctica and in the Dry Valleys, the low temperature and the low availability of liquid water, which is essential for

life

, these organisms operated very slowly, which is why I mentioned before a response time of approximately ten minutes in one generation for the fastest, if they were Luckily, we have two or three during a given three-month season during the summer, when the conditions may be suitable, so I went to the valley and entered a tent not unlike this one, with a generator and a lot of equipment. my knees and my goal was back in 2001 was to look at the overall high-level complexity of the system.

I went in looking for 12 of the 17 top level bacteria groups at that time there were 17 and there are about 60 right now. and I went in hoping to find one that hadn't been grown before I went in, I grabbed some dirt, this is in the upper right valley, I grabbed some dirt, I digested the DNA and put it in the machine, I did the analysis and the twelve. It lit up, obviously I contaminated everything, so I went back, which is very typical of me and I went back and did it again on 12 hits and then we did it again on 12, 3 more places, all 12 lit up, so it was done It was evident to me that In fact, just like in other places on the planet, we had totally underestimated the diversity of bacteria in this system, so immediately the questions that arose about an extreme system should be to have low diversity and we don't, so , why is it so diverse and what keeps it going? that diversity, so over the next four or five years a program called the New Zealand Terrestrial Antarctic Biocomplexity Study began looking and doing landscape-scale analysis.

It was the most comprehensive landscape scale work ever undertaken on the continent, the sole purpose of this was to understand the distribution of biota including microbiology and specifically to test each of these beliefs, so the first belief number one was this low diversity, so in 2001 I started seeing that, but when we did a landscape scale study this completely turned out to be true, so we have high diversity throughout the dry valley system, the second is that everything is everywhere, so in a landscape-scale study we were able to make these comparisons and what we found was that actually each valley has its own unique diversity, which was totally unexpected. and when we started looking at the system, it seemed as if each of the

valleys

had its own unique chemistry and it's the chemistry that drives the microbiology, but that chemistry is a remnant of the fingerprint of the glacial history of each of these

valleys

, as we see.

He continued and we started to look at the distribution there and we also discovered that there was an irregularity in this distribution and that the irregularity is driven by the local microclimate, so everything is everywhere, in fact each valley is unique. Belief number three refers to low activity, so the system for all intents and purposes these organisms should be operating very slowly what we did was realized. I think it's probably the first time anyone has done this experiment where we moved a mummified seal that had been in one place for 450 years and moved it from that location to a pristine location and monitored the microbial communities under that seal for five years and what we found was that the microbial community actually changed completely in just two years.

We were hoping to see something subtle. change in five and we saw a complete change so far we not only saw a complete change but we also saw a loss in biodiversity the only parameter that governed this change with the availability of liquid water increased marginally but significantly and drove the whole change in this community now why is it so important? Well, it's important because the projections for the Dry Valleys over the next hundred years are too warm. If they warm, there will be more glacial meltwater. More glacial meltwater means more extensive wetting of the system.

System wedding will mean that there is the potential to lose some of the unique biodiversity we have in the system due to these wedding events, so where are we today at this time? We have this incredible system that is incredibly well characterized, it is a The microbiological system is driven solely by the abiotic or non-living components, the physicality and chemistry of the system is what is driving this now, the hope is that in the future what we are understanding by unlocking an understanding of the message that these organisms are. In relation to your environment, we can develop a better roadmap with which to then move to more complex systems, but does it really matter?

Do bacteria really matter? I mean, you can't see them, they don't look like they're doing anything right. I think they really matter: bacteria support the foundation of all ecosystems on the planet. They are the fundamental key organisms that maintain the driving force that returns organic matter to nutrients and those nutrients are then returned to the system without them doing it. healthy ecosystem if we remove them or change them in some way ecosystem failure is almost certain, so for me these guys are the cornerstone now I'm some of my key ecological colleagues, my ecology colleagues probably wouldn't agree with that word , but I believe that these are the fundamental foundations of most ecosystems, in addition to that, they are also our biomediators.

These are the guys who come to our aid when we make mistakes. Many of you will remember the Deepwater Horizon disaster in 2010, when 4.5 million barrels of crude oil were extracted. Oil was spilled in the Gulf of Mexico, what you probably don't know is that we didn't clean it up, we made an effort, but in reality this mess was cleaned up by a small group of unknown organisms at the time they arrived. our help and flourished in that situation and took care of the problem now the deep sea disaster and itself occurred at a specific time in a specific place now we have a much more important pending issue in the climate crisis, many of you will I feel almost helpless or even wonder if the independent actions you take every day are having any impact on climate change and maybe they are not, however I believe that after 30 years of work working with the most little ones on the planet where I am.

I have seen them systematically come together and work together to sustainably and scalably alter the environment around them. In 1959, twelve very brave countries came together and decided to protect the fifth largest continent on the planet Antarctica. Now they were doing this because of the safer grade. of exploitation that could take place in the future, these were in all the big countries including Belgium, Chile, Argentina, Norway and of course New Zealand, but what made them powerful was their collective effort to focus and the passion of protect a continent from almost certain exploitation. I believe that if we come together as a global community, if we can have the same passion in the same approach, we can change this climate problem, thank you.