The Future Of

Mass Extinction Events

Episode Summary

What’s the likelihood of a mass extinction event happening in our lifetime?

Episode Notes

What’s the likelihood of a mass extinction event happening in our lifetime?

Episode Transcription

Jessica Morrison:          00:00                This is The Future Of, where experts share their vision of the future and how their work is helping shape it for the better.

Jessica Morrison:          00:09                I'm Jessica Morrison. Mass extinction events are something we're taught about at a young age, from the knowledge that dinosaurs were once the dominating species of life on this planet before they were all wiped out. But it might surprise you to know that since the formation of life on earth, 541 million years ago, that there have been five mass extinction events. With the undeniable impact that humans are having on the planet, and plant and animal species, scientists are now asking the question: are we in the middle of a sixth mass extinction event? I sat down with world-renowned, organic geochemist and Australian Laureate fellow, Professor Kliti Grice, to discuss this topic and more.

Jessica Morrison:          00:49                First, we'll start with: what are we only now just learning about past mass extinction events?

Professor Kliti Grice:      00:56                Okay. I guess anyone who's heard of the extinction of the dinosaurs has known about at least one of those events. The dinosaurs are the most notorious victims of a mass extinction event, 66 million years ago, but even worse events have previously occurred, at least four. For instance, the Great Dying, the largest of the five known mass extinction events, occurred 252 million years ago, and was associated with Siberian volcanic eruptions, when this massive supercontinent, Pangea, was formed. And likely contributed to the event, leading to global warming of the planet, release of toxic gases and metals, ocean acidification, depleted oxygen levels in the oceans, and it was probably a cascade of events that led to the observed catastrophic event of the mass extinction event 252 million years ago. So today, we do really worry about the current global warming and the COVID-19 pandemic has probably brought to the fore in people's minds about how one event can impact the lives of all people from all nations.

Professor Kliti Grice:      02:16                And while, I guess, this pandemic is nowhere near a mass extinction event, it does link up the idea of, I guess, a widespread global event that severely impacts life and ways of life. Things like increasing frequency of forest fires, which Australia has experienced, ocean acidification, expansion of oxygen minimum zones, degrading shorelines, melting ice caps, increases in pollution, such as from phosphorus and nitrogen inputs. And now we're even having plastic pollution in the oceans. And these are all points of serious concern today. So I guess this is, you know, looking at the past, we've seen some of these changes that have happened and we're also experiencing a lot of changes in our own environment today.

Jessica Morrison:          03:11                You've recently been awarded a five-year research project from the Australian Research Council to improve our understanding of past extinction events and other evolutionary processes. Can you give an overview of that project and what you're hoping to learn from it?

Professor Kliti Grice:      03:26                Okay. So this is a Laureate project and it aims to unlock an untapped record of our planet's past by analysing fossil material for new evidence of natural products in the form of biochemicals or even their recognisable degradation products, which we call biomarkers or molecular fossils. The well-studied inorganic fossil record has provided a framework for understanding major events in the evolution of life and our planet. However, this project aims to significantly advance current perceptions by assessing parallel, but rarer organic record of ancient organisms, which are entombed and exceptionally preserved in concretion fossils. Determination of the mechanics and controls of what is rapid, I guess, glue or biofilm entrapment of these organic remains will contribute valuable new information about geobiological functionality from an extension of the fossil biomarker record or a new way of interpreting our planet's past with improved understanding of extinction, environmental change and adaptation.

Professor Kliti Grice:      04:41                So we're going to have two parts of this project put together. One is to look at the preserved uncontaminated fossils, including soft tissue in these encapsulated concretions from different geological settings and timeframes by various multidisciplinary analytical techniques to answer ecological, paleoenvironmental and evolutionary questions of contemporary relevance. And the other part of the project is to perform laboratory-controlled time experiments, which artificially grow concretion-enclosed fossils. This is like basically making a fossil in the lab and this will be done with high school students, so they can come and make their own fossils and see how the fossil is growing. And we hope to identify the optimal growth conditions and establish the role of microbes and the biofilms that they make in their formation.

Jessica Morrison:          05:45                That is very cool. And what about, if there's any high school teachers listening who want to get involved, how can they do that? Can they just reach out to you by email or something?

Professor Kliti Grice:      05:53                Yeah, yeah. Yes, sure. We will have an outreach coordinator in this project who can be contacted, but in the meantime, you're welcome to contact me and we have various avenues of linking up with high school students through a number of programs.

Jessica Morrison:          06:13                That would be amazing, I would imagine. So we'll make sure we pop your details in the shownotes so anyone can get in touch. How does the understanding of past extinction events help us today and going into the future to sort of understand what's going on?

Professor Kliti Grice:      06:28                Okay. I guess we really need to be able to understand what happens before, during and after an extinction event in the past, so that we can recognise the signs of trouble and consequences of the inaction. Also, we can learn about the resilience of certain organisms and which lifeforms might compete best under certain extreme conditions, so a bit of Darwinism at its acutest.

Jessica Morrison:          06:55                So, based on your understanding of past events, what's the likelihood of a naturally-occurring mass extinction event happening in our lifetime?

Professor Kliti Grice:      07:05                Okay. That's an interesting question. Apart from the end-Cretaceous asteroid that impacted the non-avian dinosaurs and other organisms, the other four events were thousands or more year events. So, unless we're hit by an asteroid or a comet, in advance, you would probably know if an asteroid was going to hit earth. And we have no evidence this is imminent, I thankfully cannot see a mass extinction event happening in our lifetime. If naturally-occurring means not caused by humans though, then I guess about every 540 million years is possible and a chance of about one in one million within a hundred-year lifetime, if that makes sense.

Jessica Morrison:          07:50                Yeah. Okay. So it's not happening in the very near future, which is good for our listeners to know. So, that's a good thing. Do you believe that we're in the middle of a human-induced mass extinction event?

Professor Kliti Grice:      08:05                No, but at worst, we're potentially at the very start of such a concerning human-induced event, but certainly not significantly progressed on situation of mass proportions. And whether or not it becomes one depends on environmental trends persisting over the next 100–1,000 years, I guess. However, we're at a very concerning early point, experience significant changes, nonetheless, due to rapid and dramatic changes that are occurring to Earth's climate. Changing the climate will impact species and humans or perhaps relative susceptible species. All organisms will either die or adapt.

Professor Kliti Grice:      08:53                Now, human extinction is the hypothetical end of the human species due to either natural causes such as things like asteroid impacts, large-scale volcanism or anthropogenic, which is human-induced, include things like climate change, global nuclear annihilation, biological warfare and ecological collapse. There's a relative lower risk of near-term human extinction due to natural causes. The likelihood of human extinction through our own activities, however, is a current area of research and debate. I guess today's proposed extinction is very different. It's an unnatural event and it has the magnitude of a mass extinction, but this time it's not brought by a natural-occurring phenomenon, but is the direct result of an activity of one individual species on all the rest.

Jessica Morrison:          09:52                Is there any way to minimise the chances of another mass extinction event from occurring?

Professor Kliti Grice:      09:59                Interesting question. So, I guess we know from the geological record that the cause of mass extinction events, whether it be a meteorite impact or massive volcanic eruptions led to dramatic, rapid change to Earth's climate. While, I guess, we can not control large-scale natural events to minimise the chances of a human-induced mass extinction event, we need urgent climate action to mitigate the climate changes witnessed through the current anthropogenic, human, epoch, which on a geological scale are progressing at a relative rapid rate.

Jessica Morrison:          10:39                Well, that leads me pretty well to my next question, Kliti. Extinction events seem like such a bleak subject to want to research and talk about. Why do you find it so fascinating? What inspired you to get into this field?

Professor Kliti Grice:      10:52                I don't think it's bleak at all. I think it's actually very uplifting to know that even under extreme stress, life actually finds a way and sure some species experience major evolutionary events, which can be fatal, but what's nice is that new niches of organisms flourish, leading to new more evolved forms and actually we humans wouldn't exist if we did not have the dinosaur extinction. And I guess, as Charles Darwin quoted: "It's not the strongest of the species that survives, nor the most intelligent, but rather the most responsive to change."

Jessica Morrison:          11:32                Positive outlook. What does it feel like to find a fossil as a researcher?

Professor Kliti Grice:      11:38                A molecular fossil or a fossil? A molecular fossil is the exciting part because you can't see it.

Jessica Morrison:          11:44                Okay. Well, tell me about that. What is that like?

Professor Kliti Grice:      11:48                So, you know what a fossil is, like a remain, you might have seen in the museums a trilobite or an ammonite–

Jessica Morrison:          11:55                The little shell-looking–

Professor Kliti Grice:      11:57                Yeah.

Jessica Morrison:          11:57                Yes. Yeah, yeah.

Professor Kliti Grice:      11:59                What we actually do is look at what molecules are within that, the molecular fossils. So you can't actually see those, but they tell you a wealth of information about the organism, what it is, what it might've eaten, what its ecosystem was like, how it was preserved, what the environment was like. And we're talking about fossils, organisms that are extinct today. So we might get a fossil which, an example of one is the Tully Monster, is an organism that is called a 'bilateral', as its got two halves. And it's quite an interesting organism because it's got an eyeball on its back and it's got a proboscis mouth. And it was originally thought to be an invertebrate, but because it's got cartilage-type material and it's got eyes and it's got teeth, then it's been reclassified as a vertebrate. So we're actually looking at its diet, how it lived on the ocean floor. It's extinct, it could be related to some of much earlier creatures on Earth from the Cambrian. So yeah, it's really, really quite exciting to have something which is extinct and really pull it apart.

Jessica Morrison:          13:18                Yeah, yeah.

Professor Kliti Grice:      13:20                Yep.

Jessica Morrison:          13:20                What's a future area in this topic that you would love to research, Kliti?

Professor Kliti Grice:      13:25                I guess, in Australia we'd like to really look at life's tipping points and resilience of life throughout Earth's history by embracing and combining various disciplines, multidisciplines, such as geology, geophysics, with biogeochemistry, genomics, Big Data and numerical modelling to actually produce a revolutionary 4D framework that is in space and time as a foundation for policies, practices and assessments of ecosystem resilience. We also don't know a lot about the biodiversity of the deep ocean basins of today, let alone the diversity, what it was like in the geological past. So yeah, we really want to address what is meant by resilience of life on Earth, and actually learn from the past to help save and protect our own environment and planet for the future.

Jessica Morrison:          14:26                Fascinating. Fascinating. Thank you so much, Kliti, for sharing your knowledge on this topic. And we really, really appreciate you coming in. Where can listeners go to find out more about what you do?

Professor Kliti Grice:      14:37                We have a website, the WA Organic Isotope Geochemistry Centre [ERROR: Facility] at Curtin University. You can email me. We have a big team of researchers, PhD students and research fellows. We will have an outreach coordinator soon. So yeah, just check out our website, check out the people, our instrumentation, our labs, it's really exciting. We will be having probably a launch of the fossilisation lab in next year, we hope, for high school students and yeah.

Jessica Morrison:          15:14                Fabulous. Well, we'll make sure we put all of those details in the show notes for people to access. You've been listening to The Future Of, the podcast powered by Curtin University. If you've got something out of this episode, please remember to share it and subscribe to our podcast. Until next time, bye for now.