Science has a mystery on its hands: Did life begin on the surface of the earth, or far, far below it? Ferris Jabr is the author of “Becoming Earth: How Our Planet Came to Life.” He joins host Krys Boyd to discuss the amazing microbes embedded deep within the Earth’s mantle that might be keys to understanding life as we know it on this planet — as well as many others. His companion article in The New York Times Magazine is “The Mysterious, Deep-Dwelling Microbes That Sculpt Our Planet.”
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Transcript
Krys Boyd [00:00:00] Imagine if thousands of feet below you existed creatures so bizarre they could survive extremes of temperature and pressure that would be lethal to all the living things we know on the surface. So alien in their physiology that they could digest rock and excrete precious metals. It sounds like a great sci fi thriller, doesn’t it? Something we’d need Sigourney Weaver to deal with for us. But those things are down there right now from KERA in Dallas. This is think I’m Kris Boyd. Rest assured, these organisms are microbes. They are not coming to the surface to rip us apart. On the contrary, over many millions of years, they may well have helped build the very land formations that make the surface habitable for so many other living things. But most scientists weren’t convinced they existed until a few decades ago. Faris Jaber is the author of Becoming Earth How Our Planet Came to Life, and a contributing writer at The New York Times Magazine, which published his article The Mysterious Deep Dwelling Microbes That Sculpt Our Planet. Faris, welcome to thank.
Ferris Jabr [00:01:02] Thank you. Thank you for having me.
Krys Boyd [00:01:04] You start in the piece by describing this really extraordinary lab, which is located in an old mine that was donated to the state of South Dakota. What sort of work happens at the Sanford Underground Research Facility?
Ferris Jabr [00:01:18] So most of the scientists that go into this facility are physicists, and they are conducting the kind of experiments that have to be shielded from the cosmic rays that are continually bombarding our planet. So they use, you know, close to a mile of rock of the planet’s crust to shield their experiments, from those rays. But I went with a group of microbiologists, specifically geo microbiologists, and they hunt for really bizarre microbes that inhabit the deep crust, and that breathe and eat rock and do things in very unusual ways. And these microbes live in the pores and fractures of the deep crust. And so in the process of mining, often they will hit veins of, you know, just deep, crustal water that contains these microbes. And so these biologists go down there and they sample the water, they bring it back to their labs, and they study these unusual microbes.
Krys Boyd [00:02:17] So this used to be a gold mine. Part of it is closed off. But how far down can the elevator still take you?
Ferris Jabr [00:02:24] So the elevator can go, pretty close to a mile beneath the surface of the planet. It used to be that you could go closer to two miles. But after mining stopped, the sort of lowest half of the facility flooded. And you have to continually pump out that water to prevent the flooding. So, the lowest half is no longer accessible, but you can still get pretty darn close to a mile underground.
Krys Boyd [00:02:48] How surreal does that feel?
Ferris Jabr [00:02:51] It’s a really strange experience because, rationally, you know, that there’s more than three Empire State buildings worth of rock above you when you’re down that low. But all you can really see most of the time are these narrow chutes and tunnels of rock. Because to navigate the mind, you have to travel in rail cars or by foot through these very narrow tunnels. Sometimes it actually reminded me of, you know, a Disneyland or a theme park ride where you kind of like chunk to chunk going along and this sort of old, rail car type things like a wooden roller coaster. And it’s really obviously very dark down there. The only light is coming from artificial sources from, you know, a flashlight or a headlamp. And then you, you’ll sometimes see, glittering bits of mineral and rock, you know, sort of awed and then seeing these dark tunnels that you were wandering through, and there’s water and, and rocky debris everywhere. And different parts of the mine feel very different. So some sections are suffocatingly hot and humid. You can only stay in them for a few minutes at a time before you have to sort of back away and get some air. And other areas are much larger and more and they’re better ventilated, so they actually are quite cool. So there’s there’s pretty extreme temperature differences as well.
Krys Boyd [00:04:05] So not a place where humans or presumably other mammals could easily thrive for a long period of time. Why did most scientists in the past assume nothing could live more than a few meters underground?
Ferris Jabr [00:04:19] As far as science understood, there really was not, much available for life. Below a few meters, you know. It’s you could understand how if you have a really rich field of soil, that it’s very deep, you could have life extending very deep into that soil. But if you get into the planet’s actual rocky crust. Well, there isn’t much there, beyond rock itself. But what we’ve discovered over time is that actually, it’s not solid rock all the way through. It’s very porous, and it is suffused with all of these tiny fractures and fissures and pores. And there’s water, ancient water circulating through all these pores, some of which has been separated from the surface for millions, potentially even a billion years or more. And so wherever you have water, you tend to find life. So it’s and then down there, you know, some microbes have learned to get energy in very unusual ways because they don’t have sunlight. And there isn’t a lot of oxygen at down there unless something like humans digs, and allows oxygen to get down there. So they, these microbes have to get energy, by from the rock itself, by digesting rock, breathing rock, or they rely on the byproducts of kind of, innate chemical or radioactive reactions that happen between water and rock, and produce certain chemical byproducts they can use.
Krys Boyd [00:05:41] What evidence did you see of a microbe known as galleon la?
Ferris Jabr [00:05:46] Right. So, you know, it it, you know, it’s it produces these, strange, twisted, metal spires, you know, through its sort of, metabolic processes that will excrete these tiny iron spires. And when it gathers in large, masses, it kind of forms reddish water or reddish minerals or clays. So when I were down there in the mine, you know, we find this area, around one of these veins of water they’ve tapped into that’s just mired in, reddish clay, what looks like reddish clay, but it’s actually mostly composed, of large quantities of these microbes. And then if you look at them under a microscope, you can see these tiny corkscrew like metal spires that they are extruding from their bodies as a byproduct.
Krys Boyd [00:06:35] This sounds first like a very bizarre way to live, but it turns out these underground microbes may not be outliers. The majority of microorganisms on the planet may be subterranean.
Ferris Jabr [00:06:49] Right. So, you know, just a few decades ago, it was thought that there was basically no life, down that far in the crust. And now the thinking is that maybe 80 to 90%, maybe even more than 90% of all of the microorganisms on the planet inhabit the deep crust. So the majority of microbial life may not be surface life, but actually deep in terrestrial life.
Krys Boyd [00:07:13] Before anybody knew very much about microorganisms, because we had no way to see it, it was a surprise that just about anything would live underground. Will you tell us the baby dragon story that you include?
Ferris Jabr [00:07:25] Yeah. So you know our records, regarding underground life, they don’t go back that far because undoubtedly, you know, our our human ancestors were encountering some form of cave life and subterranean life going way back into our, early human history. But, there’s this really interesting story from the 1600s. There was this naturalist, who was traveling through Slovenia, Yannis Balasore, and he heard these rumors about this spring, where reportedly local residents found baby dragons all of the time. And they believe that a dragon slumbered beneath the spring. And whenever it shifted its body, it forced water to the surface. And that when, you know, there were heavy rains that kind of flushed things out and through its babies would kind of get washed up to the surface. And they were these bizarre. They were described as these kind of bizarre, pale, worm like creatures with like, bizarre little frills. And it took a long time for science to recognize that these are what we now called oldness. They are kind of aquatic salamander that lives exclusively underground, and they’ve adapted to this subterranean life. They’ve become very pale. They don’t have great eyesight. And they just live entirely in these, you know, deep limestone caves underground in the water flowing through them.
Krys Boyd [00:08:47] I still like thinking about baby dragons living underground.
Ferris Jabr [00:08:50] Yeah.
Krys Boyd [00:08:51] So how did scientists begin to identify subterranean microbes in the early 20th century, when modern science was a thing?
Ferris Jabr [00:08:59] So a lot of it happened, you know, kind of accidentally. Through other efforts in which people were basically digging far down into the cracks. So a lot of that had to do with mining, either for precious metals, or for fossil fuels. And, you know, biologists would take advantage of these mining efforts to study what was being, you know, dragged up from so far below. And they were finding a lot of microbes in these deep earth samples. But there was a lot of skepticism initially because it was possible that there was some contamination going on that surface. Microbes were getting down into the deep crust through human technology. You know, that these machines began on the surface. They take the microbes down with them. And so scientists in the beginning really wanted more evidence, more proof that these microbes were, in fact, being found way down below, not brought down from the surface. And so over time, they developed more rigorous techniques. They would disinfect the drill bits they were working with. They would track the molecules and water flowing through the deep crust to make sure that it was actually coming from down below or not from the surface. And gradually over the decades, the accumulating evidence kind of won the majority of scientists over and prove that, yes, there are substantial populations of microbes living a mile below and deeper.
Krys Boyd [00:10:18] Yeah. I was going to ask, how far down have samples confirmed the existence of some kind of life?
Ferris Jabr [00:10:25] I. My understanding is that so the further down you go, kind of the more contentious it gets. But I believe. Up to, you know, about two miles is pretty well accepted. We have found, microbes that far, and we even sometimes scientists even found sometimes more complex life, like, these tiny, worm like creatures called, nematodes. And, you know, some of them will even live that far down, which is truly remarkable because, well, you know, a nematode as a multicellular animal, needs, you know, it has much higher energy requirements. It’s doing a lot more complex biology. It needs to eat microbes itself so it you know, it has to have its own little ecosystem down there. And it is thought that life could extend at least two and a half miles, maybe even further once you get, you know, further than that, like three miles and beyond, the sheer pressures and temperatures are thought to be too much for any kind of life. But then again, that’s what we thought just a few decades ago, so who knows?
Krys Boyd [00:11:26] You note that the astrophysicist Thomas Gold became convinced in the 90s that some species might extend six miles below the surface.
Ferris Jabr [00:11:36] Yes. So Thomas Gold was a very prescient astrophysicist who made a lot of bold claims in the 90s. And, you know, he really kind of was a visionary in recognizing, the quantity and extent of deep subsurface life despite not having the hard evidence at the time. And he also made some, important observations and proposals about, you know, the potential ubiquity of this kind of subterranean life throughout the cosmos that potentially on many other planets out there, you know, these, these deep, rocky recesses provide, provide a lot of great shelter for life and that there could be subterranean into terrestrial right? Life, you know, spread throughout the cosmos quite commonly. He believed that. Yeah, that it could, our planet, it could go down really far, you know, six miles or more. We haven’t confirmed that yet. But there’s a heck of a lot of crust down there, and we haven’t been able to access, the majority of it at all. So maybe, as you know, as technologies improve and we and we get to drill deeper and deeper, we may find some more surprises.
Krys Boyd [00:12:36] And it could be that over many millions of years, the waste products of these animals might have contributed to these veins of precious metals that occur underground. How would that work?
Ferris Jabr [00:12:47] Right. So scientists are increasingly discovering that microbes are really intimately intertwined with many important geological processes. You know, they will often concentrate, precious metals. Sometimes, microbes take minerals or metals into their cells and transform them and put them out in new forms. And sometimes certain microbes will accumulate kind of a flake of metallic crust around their cells, and that metal starts to attract other bits of metal, and then that grows into a kind of or a reservoir of, precious metal. So it’s really it’s really fascinating how, you know, a lot of the veins and ores of gold and silver and other precious metals that we have tapped into over the centuries, maybe were at least partly created or influenced by microbial life.
Krys Boyd [00:13:38] First, does anybody have any idea how these things got so deep underground? Did they start on the surface somehow and migrate? Or is it possible that life originated far below the surface and came up?
Ferris Jabr [00:13:53] That’s one of the great questions that science has debated for quite a long time and is continually discussing and debating, and it’s not yet definitively known. There are many theories about the origin of life, and there are many favored ones amongst different groups of scientists. In general, I think most scientists think of life, originating in the ocean, potentially on the seafloor around a hydrothermal vent, or maybe, you know, in a much more shallow area where there was a lot of sunlight and air. But it is also possible that at least some types of life originated, in the planet’s deep crust, where you have a lot of, geothermal heat providing freely available energy and a lot of chemical reactions occurring on their own. And as we now know, a lot of water as well. And it’s possible we have to consider that there may have been multiple simultaneous origins of microbial life or similar types of life. And, and know that that this life kind of coalesced, she was single common ancestor that, gave rise to all the life we know now because we know that microbes are incredibly promiscuous and versatile and flexible, and they’re continually exchanging, genetic information. So it is indeed possible that life originated, within the planet’s deep crust. And it is also thought that at least, at least some of the microbial populations or nematode populations we are finding today in the deep crust, maybe washed down there from the surface and then adapted to life deep underground. But there’s also populations that have likely been, isolated from the surface for a billion years or more, sustaining themselves as communities for that entire time. You know, at which point, regardless of where they kind of originated, they might as well be, you know, they are essentially native to the deep crust at that point because they have been there for so long.
Krys Boyd [00:15:45] Is it possible to collect a little sample of these microbes and bring them to the surface and keep them alive in a lab somewhere to observe them?
Ferris Jabr [00:15:55] It is possible. In general, microbes are really difficult to, culture and cultivate and keep alive in a laboratory. And it’s actually just a tiny fraction of all known microbial species that science have been able to do that with. And that’s part of, you know, part of why it’s so difficult to study them. And sometimes scientists call it, you know, microbial dark matter, just the sheer number of species out there that may have never been found or be have never been successfully kept alive in a laboratory. But there are certain kinds that certainly can be kept alive. I visited, Northwestern University, the laboratory of Magdalena Osburn and her colleagues. They have samples they’ve collected over many years, some of which they’re not even doing anything special to keep those microbes alive. But when we looked at them under a micro a microscope, some of them started twitching and moving across the slides. So they have this incredible ability to, maintain themselves over incredible long periods of time, even with very limited resources.
Krys Boyd [00:16:54] What do we know about their life cycle? How long do they live? What causes them to die?
Ferris Jabr [00:17:00] So in general, deep subsurface microbes tend to be quite different from the more familiar microbes we find on the surface of the planet, and indeed on our own bodies. You know, these microbes have been found everywhere from, the deep crust, as we’ve been talking about, but also on and within the seafloor. So beneath the floor of the ocean and as well as, below thick sheets of Arctic or Antarctic ice and some of these microbes, they have very slow metabolisms, and growth cycles compared to surface microbes. They basically just live life in slow motion. They are very sluggish. They are not metabolizing or aspiring or breathing very quickly. If they do grow or divide, they do it very slowly. Some of some of them seem to have sort of million year lifespans or life cycles. They seem to be sort of in a semi dormant state for a long time. Kind of like, you know how, like, snakes will eat one meal and then they’ll be very still and dormant for a long time? It’s kind of like that, but a microbial version of it where they’re just they’re taking what energy they can find and then sort of subsisting on that for a long time in a very, low activity, kind of life. But scientists have found, you know, sort of chemically and biologically active microbes, in these sort of deep sea sediments that have been trapped there for millions of years, and they are still technically alive, even though they aren’t quite as active and dynamic as more familiar surface life.
Krys Boyd [00:18:33] I mean, it stands to reason that if you’re eating rock, it’s going to take a while for that to go down before you need to do anything else. So these things are so tiny. Do they ever leave behind like fossil evidence of their existence?
Ferris Jabr [00:18:47] Yeah. You can find scientists have found, microfossils of, various types of lifeforms going way back in history, but they, they do tend to be quite contentious the further back you go. You know, some types of microbial fossils, like, like fossilized stromatolites. So in the ancient Earth ocean, they were these vast mats of, cyanobacteria and other sort of, primordial, photosynthetic life. And, these mats can fossilize over time. And, they are some of the most important fossil evidence in the fossil record. And there’s no controversy about what they are but other types of microfossils. Do you find these, like strange, tiny, tiny shapes embedded in rock? And some scientists think that they are, you know, the fossils of ancient microbes. And others say, no, this is probably just a completely, you know, inanimate process that just happens to resemble, ancient microbes and its vague outlines. So it’s sometimes difficult to disentangle the two. And that kind of feeds into the ongoing debates about when exactly did life originate and where did it originate?
Krys Boyd [00:19:55] How does the confirmed existence of these subterranean microbes, in conditions so very unlike the Earth’s surface, broaden the possibility that we might find similar lifeforms on planets we previously wrote off as definitely uninhabited.
Ferris Jabr [00:20:12] This kind of research is really exciting to astrobiologists, and to all kinds of scientists that, you know, study the potential for extraterrestrial life out there in the cosmos. Because it really it provides a lot of encouragement and hope, you know, an inspiration that, yes, there are places, even on our planet where we thought life was impossible, but life is indeed thriving. And that may be the same. You know, it may be, a similar case on other planets as well. And it just shows us, you know, how much more we have to discover about life and in particular, its ability to cope with extremes. Because so many of our sibling planets have, much more extreme extremes than we do here on Earth. But if you know, if life can survive, even greater extremes than we realize that maybe there are pockets of Mars, you know, maybe beneath its ice, maybe, sequestered underground somewhere where microbes have managed to survive all this time. Maybe that’s true. In the atmosphere of Venus. You know, we now know that there are microbes way above us in the clouds as well, here on Earth. So I think it’s, it’s very exciting and inspiring to astrobiology to find, life on Earth in much more extreme environments than we realized it could survive.
Krys Boyd [00:21:25] And they do definitely still need water, right? It’s not simply a liquid medium in which to exist. They have to have H2O.
Ferris Jabr [00:21:32] Absolutely. As far as we know, all life that we’ve discovered requires water. At some point there are forms of life that can enter a extreme dormant state. You know, there are certain types of microbes or spores or seeds or even micro animals like tardigrades. They can, you know, really desiccate themselves and just form this incredibly resilient, spore like state where they’re not actively drinking or metabolizing, and then they can come. Back to life. They can be. They can revive if they are then given access to water and nutrients. So, you know, in order for life as a process, as a dynamic process to go on, go on. It requires water. But some life forms can sort of, you know, dip into a dormant, almost death like state and then revive themselves with water.
Krys Boyd [00:22:21] Researchers are continuing to look for new ways to understand all this. What makes let you Gila Cave in New Mexico a good place to look for clues?
Ferris Jabr [00:22:31] Let’s look. He is a fascinating one. Probably one of the most beautiful underground spaces, on our planet. Very few people have actually made it down there. It’s really difficult to navigate. It’s got a lot of sort of honeycomb like rock structures and, you know, large crystals and sort of narrow places. You have to crawl through and very steep ledges and to traverse. And there are these beautiful, turquoise pools of just the most, you know, clear and mesmerizing water you’ve ever seen. There are these, like, giant, balloon like constructions made of sulfur or magnesium. You know, there’s like, there are pearly, glossy structures. There’s just all this. It’s just this wonderland of bizarre underground formations and, what? Scientists explore it in part as sort of an analog to underground spaces on other planets. And they have found all kinds of microbial life down there, some of which is taking the rock and turning it into soil or dirt. You know, thousands of feet, below the surface. And, just doing some really bizarre and interesting things. You know, microbes we now understand are actually involved in the formation of many caves, especially limestone caves. Typically, limestone caves form through the action of rainwater kind of seeping into the ground and carving away limestone. But certain types of microbes, through their chemical processes and the gases they emit, can dramatically accelerate this process of carving vast underground limestone caverns. So microbes are all over the place underground, and they are actively involved, and creating some of these underground caves and these, magnificent, mineral structures we find down there.
Krys Boyd [00:24:16] This is all very interesting to think about. Maybe it feels a little disconnected from the lives of all the plants and animals on the surface, except maybe the surface exists as it does in part because of all these microbes.
Ferris Jabr [00:24:31] Yes. This is one of the most fascinating, ideas out there in this world of geo microbiology and this larger idea of, you know, earth and life evolving and continually changing each other. So the continents, you know, the the large landmasses we have on Earth today are made of granite. And as far as we know, Earth is the only place in the cosmos that has an abundance of granite. We’ve never found it in significant quantities anywhere else, and that may be because life was integral to the initial formation of granite some 3 to 4 billion years ago. And the leading theory is that granite was formed by a kind of recycling of oceanic crust, which is made of basalt, and basalt is much heavier and denser than granite. So ancient ocean crust was recycled by geological processes, melted and then turned into granite, and granite, being less dense than basalt, floated on top of basalt and then over time accumulated and rose above sea level. And that’s how we got these large land masses. Well, by inhabiting the ancient crust and by dissolving it, microbes were essentially accelerating this process. They were hydrating the ancient crust. They were bringing in these wet clay mineral byproducts and lubricating the ancient crust. So they accelerated, the ocean crust, subduction and melting and recycling into granite. And some scientific models suggest that were it not for, microbial life, that we may have had much smaller continents, you know, that that, we never that the planet never would have developed these large, exposed landmasses we have today. So it is possible that, life, you know, basically created, the terrestrial framework that all terrestrial life now depends on.
Krys Boyd [00:26:16] So I just want to make sure that I’m understanding this correctly. Microbes helped form the granite that forms the continents that give us a place to live.
Ferris Jabr [00:26:26] Exactly. And that’s right. Yeah. It’s, it’s it’s. And it really flips things around to think about it that way. Because we’re so used to thinking about life, taking advantage of what is already there, needing, prerequisites. You know, we have to have a planet that has liquid water that is just the right distance from the sun, that has a stable atmosphere. But there’s so many things life does to make the planet more habitable over time. You know, all kinds of life have continually and profoundly altered the continents, the atmosphere and the oceans, often in ways that have allowed new waves of life to emerge, and to take advantage of what life before them did. You know, life is why we have a breathable atmosphere, a blue sky. It’s why fire is possible. Life calibrates the chemistry of the modern oceans. Life converted what was once barren crust into fertile soil. So all of these, you know, defining features of a planet that we kind of take for granted or think we’re always there, or just where the default state we’re actually made by or influenced by life in some way over billions of years.
Krys Boyd [00:27:34] Yeah. Reading your work made me think about the fact that we often conceive of the Earth, as you said, as kind of, you know, like the perfect place for life to emerge. But it was a little bit more, less like, like a finished piece of furniture and more like something that came flat packed from Ikea. Like the elements were all there, the materials were all there, but assembly was required and it had to happen in a certain way.
Ferris Jabr [00:27:57] Yes, I love that Earth assembly required. Life gets to work. It’s so true. I mean, the the ancient Earth 3 to 4 billion years ago was much more of a jumble of raw material. It was compared to our planet today. You know, the ancient atmosphere was probably this hazy, smoggy orange sky that was dominated by carbon and methane and nitrogen with no free oxygen. Today we have this beautiful, blue sky that’s 21% oxygen. Life is the reason for that transformation that completely revolutionized the chemistry of the entire planet. And in fact, we have something like 6000 unique mineral species on Earth, which is vastly more than Mercury or Mars or the moon or any other planetary body. Half of those mineral species can exist only in a high oxygen environment, which did not happen before photosynthetic life. Like cyanobacteria and algae and plants oxygenated the atmosphere, so even Earth’s basic geology and mineral diversity is largely a product of life.
Krys Boyd [00:28:54] So we all understand that living things can evolve over time in response to environmental conditions. But you’re reminding us that living things also can change the environment.
Ferris Jabr [00:29:05] Exactly. And this, this reciprocity, this idea of coevolution that, you know, that it goes both ways, that life is profoundly transforming its environment at the same time, that it’s adapting to its environment. That is really coming to the forefront now, because for so long, science has segregated biology from geology and has thought about the changes the planet has undergone as parallel to the evolution of life, but not necessarily into. Of the interconnected. But now scientists are realizing just how interconnected those processes are. And indeed, Earth system scientists think of it as a single integrated process that life and Earth are evolving together as one system.
Krys Boyd [00:29:45] So how does life as a geological force compare with, like, earthquakes and volcanoes and glaciers?
Ferris Jabr [00:29:52] What we’re, you know, increasingly recognizing and appreciating is that life can be just as powerful and sometimes more powerful. I would argue that the oxygenation of of the planet by life is probably the single most profound transformation that it has gone through, of any kind, really. I mean, that really changed everything else. And it’s hard to think of a purely geological example that was, you know, quite that dramatic, you know, barring the initial, formation of the planet itself, which is an incredibly, dynamic and violent and purely sort of geological and cosmic process. But after that, it’s, you know, really life, I think that has, powered and, and sort of been responsible for some of the most dramatic and profound transformations.
Krys Boyd [00:30:39] Ferris what is the Gaia hypothesis?
Ferris Jabr [00:30:42] So the guy hypothesis is, it’s it’s kind of the most popular version of an ancient idea, which is that Earth itself is alive. And it was conceived by British scientist James Lovelock in the 1960s and later developed with American biologist Lynn Margulis. They propose that wherever life emerges, it inevitably transforms its home planet, and that together, life and the greater planetary environment form a single, self-regulating living system. You know, James Lovelock’s initial insight, he was working for NASA, and NASA asked him to help them find ways of detecting life on other planets. And Lovelock realized you may not even need to go to another planet to determine whether it has life or not, because wherever life emerged, it would inevitably, shift the chemistry of that planet’s atmosphere. And that is something that scientists can read and study from afar. For example, aliens, you know, seeing Earth from afar, would recognize that life is there because it has a high oxygen atmosphere. And that can only happen if life exists and is pushing the atmosphere into a chemical disequilibrium that would not otherwise exist if it were not for life. There would be no oxygen in our atmosphere, and we would have a carbon dominated atmosphere, just like Venus and Mars. So Lovelock turn that around and said, why not look at other planets atmospheres, and see if we can just read their chemistry to determine whether they have life there. And so he and Margulis, you know, really advocated this idea that life is so such a profound force on the planet and so intertwined with any planet’s chemistry and geology and structure and behavior, that it really makes more sense to think of any planet with life on it as a living planet itself, that life emerged from the planet. It loops back to transform the entire planetary environment, and the whole planetary system then takes on the features of life that planets develop these rhythms and self-regulating processes that resemble those of much smaller life forms. And these ideas were very popular with the general public. When Lovelock first published his book on Gaia in 1979. But scientists really harshly criticized and ridiculed, and at the time they did not like the idea of Earth being thought of as a single giant organism. But what Lynn Margulis helped clarify over time is that’s not what they were saying. They were not saying that Earth is an organism in exactly the same way as a bacterium or a bird. Rather that it is a vast living system. It’s more like the confluence of all of other ecosystems. And that living systems, even at the scale of a planet, can have many of the fundamental features of smaller life forms and resemble them in many ways. And so in recent decades, you know, so much evidence has come to light that aspects of this whole thinking, of this whole guiding way of thinking are being much more accepted than they were in the past. And, you know, it is now universally accepted within science that life indeed transforms the planet very profoundly and that Earth and life co-evolved, changing each other, and that together life and Earth from a single, highly interconnected system. So that is all well accepted at this point and is in some ways the legacy of Gaia.
Krys Boyd [00:33:53] Why do some people like this metaphor of a redwood tree? How can that example help us understand the way this works?
Ferris Jabr [00:34:00] It’s a wonderful metaphor because it really helps you visualize what’s going on. So by weight and mass and volume. You know, the majority of any mature tree is actually dead wood. It is just dead tissue that is ringed and laced with living cells and thin strips of living tissue here and there. Similarly, most of Earth is just inanimate rock which is wrapped in this incredible flowering skin of life. Well, just like those thin strips of living tissue in a tree are essential to keep the whole tree alive in the planet’s flowering skin sustains a kind of global being. And we see this is true for all complex life forms. By weight, the human body is mostly water. But nobody disagrees that a an individual human or individual tree is alive. So why can’t we apply that thinking to an even larger scale like the planet? So we see that all complex life is an intricate network of, you know, connected components, some of which are animate, some of which are inanimate. But the system as a whole is what is alive, and that’s what matters.
Krys Boyd [00:35:04] You mentioned that, you know, scientists now look for, chemical signatures elsewhere in the universe that might indicate the presence of life. And this was Lovelock’s big contribution, or one of them. Are any planetary hunters looking for exoplanets that maybe don’t yet have the chemical signature of Earth, but might look like Earth did, say, 3 billion years ago when the potential was all there? But not everything had come together yet.
Ferris Jabr [00:35:33] Absolutely. I think, you know, scientists are constantly scanning the skies, scanning the cosmos, for potentially habitable planets. And they’re continually debating what the definition of a habitable planet should be. You know, what are the criteria? Because we are limited to our our end of 1 or 1 example of life here on earth. But we have to be more open minded and recognizing that not all life in the cosmos is going to look exactly like life on our planet. And so, you know, we’re we are constrained in that way until the day that we finally find, you know, concrete evidence of extraterrestrial life. But in general, you can absolutely. It’s out there and say, does this resemble kind of a proto earth, not just what Earth looks like right now? Or are there sort of the basic features there that would allow life to emerge at some point?
Krys Boyd [00:36:27] Does the Gaia hypothesis have implications for how we understand climate change?
Ferris Jabr [00:36:33] I think so. I think part of the reason we are seeing this emerging movement right now that is sort of, you know, reaffirming the importance of the co-evolution of earth and life and of thinking of the planet as living is its relevance to what is happening to our planet right now, to the current planetary crisis, to anthropogenic climate change. I think there’s a massive difference between thinking of ourselves simply as inhabitants of the planet versus being continuous with the planet, you know, seeing ourselves as an extension and expression of Earth. And that’s also massively different from, you know, this so-called being, passengers on Spaceship Earth that was popular a few decades ago. I think we have to realize that we and other lifeforms we are, we’re not just hanging on for the ride here on this planet, nor are we the masters of the planet that we are all, you know, components of this much larger, much more complex living system. And so then the question becomes, how can we disrupt the overall system, you know, as little as possible? And what can we do to sort of amplify the innate self stabilizing processes? The planet has already co-evolved itself over billions of years. So by burning fossil fuels, we are, you know, introducing a major, disruption to the planet’s innate rhythms. We are going into the Earth, unvarying ancient life that would have been sequestered there for millions of years, burning it and then releasing that carbon to the atmosphere. So that’s a major perturbation of Earth’s, you know, long term carbon cycle. And it is throwing the living planet into severe imbalance. So the task before us now is to correct that imbalance, to develop new energy infrastructure, new forms of agriculture, new ways of being a part of this planet that do not disrupt, these, you know, massive, this massive living system and these really profound ecological rhythms that have, you know, co-evolved over such great spans of time.
Krys Boyd [00:38:28] So learning how the planet has historically kind of self-regulated will help us understand better why those processes may no longer be so effective, right, at enabling the survival of existing species.
Ferris Jabr [00:38:41] Absolutely. I think the most clarifying way to understand what is happening right now is through this holistic Earth system science perspective. You really have to see the connections between all the different components if you want to understand the system as a whole and how our actions, you know, have profoundly influenced it in just a few centuries. Just a few millennia. You know, no species before us has changed as many layers of the planet as radically as we have in such a short space of time. So while all life, you know, dramatically alters its environment, we are unique in the combined speed and scale with which which we have done so. And we are now reconciling, you know, reckoning with that. And, part of that is intervening with the necessary speed and scale. And that’s kind of where we’re falling behind.
Krys Boyd [00:39:27] How does the planet naturally, well, without human intervention, how does the planet absorb and store and transfer energy?
Ferris Jabr [00:39:37] I’ve come to think of the ubiquitous presence of life across the surface of the planet as its kind of collective planetary anatomy, and the behaviors of all of these living tissues as the planet’s metabolism or physiology. And scientists will sometimes speak of it this way as well. You know, they’ll talk about Earth’s total photosynthetic productivity, which essentially means if you add up all of the photosynthesis going on on land and in the ocean, you know, and land and plants and, and plankton and all the other photosynthetic life forms, we can think of that as the planet itself, taking in the energy from the sun, turning it into chemical energy, using it to perform the work, the cellular work that is so fundamental to life. So, we start to see the planet itself having this incredible living photosynthetic skin that is, absorbing the sun’s energy and using it to perform all of these miraculous activities. And, the way, you know, that immense power of the planet has co-evolved with its geology, and led to some really astounding feedbacks. You know, so the, the presence and activity of photosynthetic life is basically, a really powerful carbon sink because it’s continually pulling in carbon from the atmosphere as part of performing photosynthesis. And then when photosynthetic matter dies, it often sinks to the seafloor or is buried on land. And that is where we get these immense stores of carbon in the deep crust, these fossil fuels, as we call them, this, they are part of the long term carbon cycle of the planet. And the planet has this innate capacity to pull itself back from extremes. If it if it enters a deep freeze or an extreme hothouse state, it can pull itself back to a more stable climate. And life has been intertwined with that so-called planetary thermostat, that self-regulating process, for a long time. But it operates so slowly through geologic time. But there is no way we can rely on it to stabilize the planet’s climate right now in time to spare us our species. And that is why we have to act so quickly ourselves.
Krys Boyd [00:41:48] Ferris underground microbes are likely still contributing to the conditions we find on the surface. I’m wondering, though, does it work the other way? Are there things we might be doing to change the planet that enable or hinder the ability of underground microbes to keep doing their thing?
Ferris Jabr [00:42:07] There certainly are. And there’s a lot of, debate and discussion about this. I mean, one of the best examples is probably, you know, this prospect of deep sea mining because we know for sure that, deep sea mining, you know, really, interferes with and sometimes, you know, completely destroys these rather unique and fragile deep sea ecosystems. And, you know, part of these ecosystems are kind of on the surface of the seafloor. And they kind of conglomerate around these, hydrothermal vents where there’s enough, warmth and energy for all kinds of life to exist down there. But it also they also extend deep into the seafloor and beneath it. And that is largely microbial life. And if we go, plunging into, that part of the planet, we simply don’t know exactly how it is going to change the microbial life down there. And the same is true for, fracking or deep mining or deep drilling. You know, that is going into the planet’s terrestrial crust, where we simply don’t fully understand how it is changing these, deep crust microbial communities because they’ve so recently been discovered and are still, you know, compared to surface life, so poorly understood.
Krys Boyd [00:43:15] You ultimately are just fascinated by this idea that all species that we know about may be part of a kind of larger life form that is our Earth. Why do you think, considering the planet that way is so potentially transformative? Well.
Ferris Jabr [00:43:33] I think that, you know, I have come to see all life, as a physical, literal extension of the planet. And I like to make an analogy that I think is helpful, to a vast beach. So imagine a vast beach from which spontaneously emerge all manner of sand castles and sand sculptures, just because those structures, you know, have attained a new level of organization and complexity does not mean they’re suddenly separated from the beach. They are still made of the same grains of sand that surround them. They’re still literally the beach. And I think it’s exactly the same with life and earth. You know, life emerged from Earth originally, it was only the matter of the planet that was available to become life. Life is made of Earth to this day. It returns to Earth. So what we refer to as life is really Earth animate. It is the matter of the planet that has become animated. So that gives a literal, material scientific truth to this idea. You know that everything is connected, which can sound kind of trite, when you just throw it out there. But I think increasingly, Western science is recognizing that there is a material reality, behind that statement, behind that ancient sentiment and intuition. And so for me, that profoundly changes the way I think about myself and the human species and indeed all life on this planet, because I did not I previously saw us as kind of separate from it and kind of existing on the surface of the planet, rather than being physically continuous with it.
Krys Boyd [00:45:03] Faris Jaber is the author of Becoming Earth How Our Planet Came to Life, and a contributing writer at The New York Times Magazine, which published his article The Mysterious Deep Dwelling Microbes That Sculpt Our Planet. Ferris, thanks for making time to talk about this.
Ferris Jabr [00:45:18] Absolutely. Thank you so much for having me.
Krys Boyd [00:45:20] You can find us on Facebook and Instagram and subscribe to our podcast wherever you get podcasts, or listen right at our website. Thanks, Craig dawg. Again, I’m Chris Boyd. Thanks for listening. Have a great day.
