I love how precise you are with your languag., So many channels that talk of anything related to science use ambiguous language, confuse theory with fact or just straight out decieve. Another great video.
Thank you so much! This means so much because I was not always good at doing that, but have really worked on improving my concept clarity and making sure I thoroughly explain things that are ambiguous :)
Another concise and well structured video, great work, and really interesting too. I have had the pleasure of seeing Ediacaran fossils in their native habitat - the Ediacara Hills in the state of South Australia, and the type location, Brachina Gorge. I like to think they are the Hipsters of the geological record, as they were already around before life got popular in the Cambrian.
Another awesome video, your enthusiasm and positive fervor for your field of study is really empowering. The way you explain and elaborate everything in a some what simplified way is really helpful. For someone who hasn't been able to finish as much school and education as I'd like to yet these videos are truly great. Thanks for your uploads
Thank you so much! I am so glad you enjoy my uploads even without being in this field, and I am glad my passion is translated through my discussion on this research, it is truly so exciting to me! ;D
Oxygen. This is so cool. By the way, I have difficulty communicating because I had a stroke in Broca’s area, the part of the brain that controls speech. 2/8/2021 but I lived again. (My wife helped me compose this.)
I'm SO proud of anyone who is the courage to face having to relearn what we thought we would NEVER have to relearn -- walking, chewing, speaking. I commend you! And I'm glad you have such a partner who cares so much. Hang in there! ❤
This is a fascinating topic and this video provides an insightful, detailed and balanced analysis. Great job! Thank you! I think we need to be cautious of looking for a single driver in the long term evolution of such a complex and interdependent system. Also, we should be warry of deriving too much guidance from analogy to modern conditions. After all, there is a strong correlation between ice cream consumption and shark attacks, though this correlation has an independent geographic limitation since it is not observed in St. Louis. 🙃
Fascinating topic. I've always been interested in the fact abiogenous seems to be easy as life emerged so soon after earth's formation and yet it took forever for complex multicellular organisms to evolve. I had just assumed this was do to the need to build up oxygen in the atmosphere. Your video shows, like many things in science, the underlying causes are much more complex.
Yes, I think there are many times we simplify things down to a level that is almost incorrect (I am guilty of this as well, especially when I am talking about things outside of my expertise). But for this video, because it is in my field of research, I really wanted to lay out the complexities of everything involved because 1. I think it's important for us scientists and science communicators (including myself) to address the unknowns, and 2. it is just so interesting (at least to me)! ;)
A study published this month (July 2024) in Nature Ecology & Evolution used analysis of genetic mutations and what we know about the normal mutation rate to put LUCA at 4.2Gya -- this is the Last Universal Common Ancestor to all life known on Earth today. So around 350 million years after the final formation of the Earth! Yet now we've also discovered so-called "dark oxygen" on the ocean floor that's produced by geological processes! These little polymetallic nodules generate electricity and they believe are causing the molecular oxygen via electrolysis of the water.
I've been enjoying with this series, but never seen her so happy, smiley face here & there (giggling?). That may mean herself enjoyed & satisfied with this footage as we viewers did. Seriously, this could be one of the best presentations in every aspect. Great enthusiasm & effort is tangible, as summarized in 20 odds minutes is a masterstroke. Well-structured narration is informative & effective more than usual, which provides sources for thought! She handled this very intriguing, complicate & fascinate subject pretty well, simple & clear. This video shares a positive view on the link between oxygen level & animal evolution. On the other hand, to take rising oxygen level for villain or destructive factor is another version of earth history, which I watched recently. That was equally interesting & very high standard. Even 1% of increase should have had enormous impact, given the large scale, if not planet level! This oxygen issue reminds me of appearance of gigantic insects. So inspiring it was, here's a homework for you: about fluctuations of oxygen levels. How about potential influence by groups of newcomers, oxygen consumers? How to reach equilibrium? Did suppliers of oxygen get any benefits from them? You may need sequels. Many thanks & keep it up, geo giggle girl!
Cool presentation! I have a few thoughts/questions: 1. With regards to temperature and oxygen, an increase in T would lower the solubility of oxygen in the water; so there’s synergy. 2. In my understanding, Cambrian animals were benthic or demersal. These environments tend to have much lower oxygen diffusing from the atmosphere and more reducing conditions due to chemical interactions with the sediment. 3. In relation to the above, as oxygen levels increased, iron dissolved in the water column and in the interstitial spaces of the sediment would remove lots of oxygen. 4. Functional anaerobic microbes wouldn’t decompose organics as quickly during periods of low oxygen, leading to a buildup in the shallows. When oxygen levels increased to the point where the microbes switched to aerobic respiration, their decomposition rate would increase by an order of magnitude, flooding the system with nutrients and dissolved organics (like the Gulf of Mexico “Dead Zone”), while simultaneously sucking oxygen from the water column. Are those factors being considered? Thanks!
Hmm Ive seen quite a few genetic algorithms simulating very simple evolution, say to construct clocks once you introduce some basic parts and attractions between them. A common pattern would be the very rapid evolution of a comparatively simple mechanism then a long time of no real developments (The age of the pendulum.) then the very first most basic clock mechanism would appear and there would follow an explosion of rapidly more accurate and sophisticated clocks with multiple hands etc. Obviously life is many orders of magnitude more complex, but I dont think that difference in complexity would inherently rule out something similar occurring in nature? Especially with the vastly greater time scales involved. I.e. If a more complex life form would have an evolutionary advantage in any case, would there need to have been any external change to trigger that development? Couldnt it have just been a product of the difficulty in making that evolutionary leap regardless of the variations in temperature, oxygen etc.?
It's a question of having sufficient energy to power a mass of cells. There are many metabolic pathways invented by prokaryotes, but most of them yield barely enough energy to run one cell. Oxygen metabolism, which is what animals use, yields by far the most energy. Complexity can't evolve without the extra energy to create specialized cell components and cell types.
Do we know what the atmospheric pressure was in the past, and how does atmospheric pressure affect this oxygen threshold? I would think at higher pressure it would be easier to breathe at the same % levels of oxygen.
That is a GREAT question! I have generally assumed that atmospheric pressure has remained relatively constant through Earth's more recent history (pretty much everything after the Hadean which ended ~4 billion years ago), but now that you say that I am not sure I have actually ever read any papers on atmospheric pressure through geologic time, so I will have to look into that! Thanks for the comment! I hope someone more knowledgeable than me on this topic can reply to this thread and enlighten us ;D
Maybe sharks like ice cream has anyone tested to see? More ice creams on the beach, sharks come in closer sniffing that vanilla, closer interaction of humans and sharks increases frequency of attacks. Maybe there’s a preference for some flavours, eg cookie dough, or choc chip, research into this could be useful in reducing shark attacks- I’m going to try and get a research grant, obviously a lot of it would need to be spent on ice cream but I’m prepared to eat it in the name of science.
Very interesting indoctoration of oxygen and Co2 impacts, on the evolution of life... I would love to see a video of your findings, on Co2 emissions, and it's impact on the earth's response,, both positive and negative... I believe there still hasn't been enough study to show direct links on the effects of present 'climate change', with regarding the increase of Co2 emissions in our atmosphere... There's a lot of theories out there,, but no factual data to explain whether or not our planet is 'naturally' going through a geological transformation on it's own,,, or proof or data to show that the rise of Co2 emissions is directly impacting this transformation... I truly believe that the more educated and informed we humans can become in discovering the 'facts',,, the better we become to making crucial adjustments in responding with our technologies going forward...
Great video as always. I am impressed by the amount of research you do. Do we know the genetics that enable low oxygen capable animals to survive with little to no O2? If we do, we should be able to get an idea of the relative age of these genes. By we, I mean people who know things about genetics. Not me. It strikes me that the special thing about animals is movement, which requires more energy than being stationary, and therefore seems to require aerobic metabolism. Sponges don't move, and seem to get along better than most animals in the absence of oxygen. IIRC, the larval stages of sponges are mobile. This suggests an hypothesis: Sponges developed during a era of unstable oxygen levels, only producing larvae during periods of high oxygen level, when there was a chance the larvae could settle and mature before the oxygen levels fell. Animals that couldn't sit still during low-oxygen periods had to wait until the NOE.
Not me either lol! I thought about including something about genetics in the video, but I just don't know (or understand) enough. Funnily enough, when I was an undergrad one of the avenues I considered was genetics, but then I realized it is super complicated lol I hope somebody else that knows about genetics can answer this comment better than I can haha ;)
Many animals have transcription factors called HIF-1("hypoxia-inducible factors”) that regulate oxygen consumption in low oxygen conditions. But interestingly the most basal animals, sponges and ctenophores, lack HIF-1. HIF-1 appears in Parahoxazoa (bilateralians, placazoa and cnidarians). So this suggests that sponges and ctenophores evolved at lower oxygen levels, while the Parahoxazoa split off from them and evolved in higher but fluctuating O2 levels. Cf Wikipedia "Hypoxia-inducible factor". Thus sponges and ctenophores may have evolved earlier in the Neoproterozoic (Cryogenian? or early Ediacaran?) than the Parahoxazoa (later Ediacaran?)
I think the atmospheric conditions and ozone layer may be the biggest factor. Also the sun's radiation output and orbit of earth affected th ability of complex biology to occur.
A very interesting video! The crude picture I had was that the deep ocean was euxinic during most of the Proterozoic (the Canfield ocean), but that the breakup of Rodinia allowed ocean circulation changes that oxygenated deep ocean waters, allowing faunal assemblages to establish themselves during the Ediacaran. Then this oxygenation of deep ocean waters intensified in the Cambrian. That is probably grossly oversimplified... for one thing, I'm foggy about the details of ocean current changes during that period. The general picture I have of the development of life on Earth is that plate tectonics took a *long* time to get started and complex life probably depends on it -- so one question for the habitability of super-earths is what happens to plate tectonics as you make a terrestrial planet bigger or smaller?
What happens when you consider that minimum oxygen levels are not a trigger, but a condition? Even when conditions are met, evolution is still very much limited by chance. Things can happen, but they don’t necessarily do.
Exactly! That's what I meant by 'it was a prerequisite but was it a cause?' But then we also have to think that maybe it kinda was a cause because maybe evolutionarily, everything was ready to go but couldn't until oxygen rose... But ultimately, I think we've learned that the question isn't 'did oxygen cause animal radiation' but rather 'did it prohibit it for the long period before the ediacaran/cambrian?' And if it wasn't the major prohibiting factor, maybe something else was limiting... I mean there are so many possibilities so it's hard to look at it like one thing was the 'major' thing, but rather it was many things all at once. It's a difficult question for sure! But also a super facinating one ;)
Thanks. I have to admit that I had to switch my listening into what I call "Lecture Mode". It was very interesting. Question: How long do you think that it took to oxidize all of the materials that we now find as oxides? It obviously would have taken much quicker than 1.5 billion years.
That's a great quesiton, but I think it is impossible to say because compounds that became oxidized after the initial increase in oxygen were continually reduced by both abiotic and biotic processes. Biology itself is a cycle of oxidizing and reducing metabolisms, so the presence of life during these oxygenation events prevents us from estimating the amount of time it took for everything to become oxidized because technically it never did. Even today, reduced compounds exist and fuel the disequilibrium that allows life to go on. The day that everything on earth becomes oxidized is the day that life on earth is no longer possible, at least life as we know it ;) Edit: if you are asking more so how long it took for oxygen to oxidize the most readily available things, like reduced iron for example, then for that I would say it is also difficult to say haha! Because the GOE rose oxygen to near modern levels but then pwent back down again and a lot of the Fe that was oxidized in the process (that formed BIFs) became reduced again by the abundance of sulfide in the ocean from sulfate reducing bacteria, so it was a fluctuating trend rather than a straight line so a 'how long' is not representing a linear trend if that makes sense... The reducing bacteria and other reducing processes greatly interferred with this trend. For that reason, it is completely reasonable to say that it took 1.5 (or over 1.5) billion years for oxygen to oxidize all the minerals that we recognize today as oxides. I would say a more accurate answer is 3.5 billion years. Because technically oxygen was initially produced as early as 3.5 (or earlier) billion years ago, and ever since then it has slowly been oxidizing everything on earth (with downward fluctuations of course) until we reached our current senario today. I hope that makes sense (I feel like that was really rambly but that's the best I can do at the moment haha). :)
So, I know I'm old now by finding out my colleague and former roommate is now back at UTEP as an assistant professor. Dr. Jay Chapman - you should definitely get with him on anything structural, my friend. He's god tier at that shit. I will also definitely be trying to stop by campus and visit him on the 9th-10th of Feb. Also need to check in on Libby and Phil. Cheers!!
That's so cool! Actually Jay recently moved into the office right next to my lab, so I am well acquainted with him, he's great! Also love Libby and Phil! I hope you have a great visit ;D
Rachel, one of your commenters brought up a separate topic of abiotic oil. I concur with your response…but what can you tell me about Titan. Apparently a Lake Ontario-sized lake has been discovered on Saturn’s moon Titan that is composed of hydrocarbons, specifically liquid ethane. By some estimates, the contents of this lake could be equivalent to as much as 9 trillion barrels of oil. Even NASA suggests that Titan could have “hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth.” What do you make of this…it would obviously be abiotic…hogwash or reality?
Oh see this is a brilliant example of something I didn't think of! I think that Titan is a whole separate situation because photochemistry has allowed organic chemistry to go crazy there given its abundance of methane to begin with. This feels like when I tried to explain to my mom that I was taking an inorganic biochemistry course and she was like isn't that contradictory? haha I think the two scenarios (Earth and Titan) are very difficult to compare, so is abiotic 'oil' possible? Yes, on Titan, but not on Earth... Although I am not sure if what is being formed on Titan would count as what we define as 'oil' on Earth... I just looked it up and they are careful to say that Titan has abundant "liquid hydrocarbons" rather than saying "oil" so I am curious what the composition is and if it is made of much simpler organics... But I am no Titan expert, so I can't answer this question intelligently haha, I hope a Titan expert will eventually chime in on this thread! ;D
Yes, I agree, not oil as we earthlings perceive it….but, nonetheless, a form of hydrocarbon not related to biological origins. So fun to ponder all this. So many unknowns. I do think your response was intelligent and logical. Thanks also for your thought provoking video on oxygen and it’s relationship to early evolution of life on earth.
Worth mentioning: en.m.wikipedia.org/wiki/Spinoloricus_cinziae A lorciferan that needs no oxygen at all. Of course it is highly derived, and doesn't represent a basal condition. Still, the minimum O2 concentration requirement for animals seems to be 0%
Very cool! Yep, as I mentioned, there are plenty of animals now found to either not need oxygen at all, or to only use it when it is present, so the limit is kind of obsolete. Although, as you mentioned, we need to make sure we are looking at basal rather than derived traits in order to use this as an argument for early animals. :)
Animalutiom is now a new awesom word! As you know I'm a Precambrian rock guy and life isn't my thing. So I look forward to these. I have a request. Feel free to ignore. Can you do one on the atmosphere evolution from the Hadean to Cambrian? Along with atmosphere thickness thru time?
Another, probably related question: is there a relationship between increased oxygen and the evolution of hard parts? Edicaran biota did no biomineralization. Cambrian biota biomineralized like mad, facilitating the beginning of a predation/protection arms race. Is the invention of hard parts related to increased availability of dissolved oxygen? Related to availability of dissolved calcium due to increased glacial weathering? Other? Paleobiogeochemistry is pretty interesting.
Well I assume the formation of hard parts requires more energy and thus, higher oxygen levels for animals to carry out this process. Also, you are right that the increased weathering at the time increased the Ca flux to oceans, so there was a perfect storm to cause the evolution of hard parts around this time. However, there sudden appearance and radiation at the Cambrian is puzzling to me given that these conditions should've been met in the Ediacaran. So I will look into it and make a future video! I imagine maybe it had something to do with the time needed for natural selection to led to hard part favoritism, or maybe the stabilization of well-oxygenated zones in the ocean for benthic ecosystems to gain more energy. Not sure, but I will figure out whatever we know or think and make a video! Very great topic, thank you for this comment :D
Wonderful presentation. Two comments: Nick Lane's 2002 book "Oxygen, the Molecule that made the World" covers some of the same ground, but does not explore this particular chicken-or-egg aspect. The second is a whoopsie... At 8:42 you said that primary producers get oxygen from CO2. They don't .. The released oxygen comes from water. The CO2 goes into the sugars they're making for themselves. It's a nuance, but it's important.
Yes, I am fully aware they use the CO2 to make biomass and split water to make oxygen, I meant to suggest that they use the CO2 and light to gain energy which they use to split the water molecule rather than suggesting that they actually make oxygen from CO2 alone, so my bad! Sometimes I tend to skim over things assuming people will know what I mean, but you're completely right I should've clarified that so people don't get the wrong impression, but thank you for clarifying here in the comments in case people are curious! ;) Also, yes, I love Nick Lane's book about oxygen as well!! ;D
I am not sure that purely the fact that today, we have animals which tolerate very low oxygene levels, invalidates OCH. We also have whales and dolphins, which never go on dry land, but for their evolution, dry land was necessary. Maybe high oxygene levels were necessary to kickstart animal evolution, but later adaptations allowed animals to deal with lower oxygene levels too.
Ms. Geo Girl, No one doubts your genius and if I criticize it is meant to be completely constructive because I think you are brilliant. Since you are not speaking to impress a grad-student or a professor, you might slow it down a bit and use a few pauses for dramatic emphasis. Evolution is a wondrous story and speculation of life on other planets is even more exciting. You might be sharing your knowledge with ordinary people who could not afford college or had a different major but are really interested. To eliminate lapses, pauses and stumbles is a practical consideration to tighten your clip up and make it presentable. However, by removing every little breath and pause makes you sound less human and your talk homoginized. Don't follow the text book so closely and make it a story that inspired you personally and excites you about science and evolution. Slow it down a little and have some one in theater arts or lecturing, critique your work. Feel free to ignore them if they advise something that is not your style. My simple rule is, Be flexible.. Again I will say I think you are brilliant and thank you for your clips.
Other scenario : Few if any pre-Edicaran soft bodied fossils formed. They MAY have been around, but how can we know ? The human lineage certainly has expanded greatly over my lifetime due to fossil discoveries. Those "explosions" may have been just a continuous rate of evolution, marked by rare fossil deposits. I wonder what the basal jellyfish ancestor looked like ? Bet it almost never fossilized, and most of those rocks are long gone anyways.
This is awesome! I wonder if increased levels of oxygen is a self sustaining loop in the biosphere. Complex life thrives on O2, so it would be advantageous for them to establish systems that maintain high levels of it.
Thanks a lot for creating & sharing - highly appreciated! BTW 4:40 love that quiet sense of humor: just looking at these most adorable curves alone would have made my evening...
Rachel, I'm curious about your procedure for producing these videos. Do you write a script? Or do you just make the slide show and use them as an outline, but talk off the top of your head? Do you make many mistakes while you're talking that require you to cut and edit your video? Or do you do it all in one take?
I just make the slide show and use that as an outline. I kind of think about what exactly to say as I make the slide show and then when I film I speak from my head, but thankfully I know that I can edit so sometimes when I film I try a few different renditions of each concept explanation and then pick my favorite while editing and just cut out the rest. :) This may change in the future but that’s currently just what comes most natural to me when producing these :)
I think that from an evolutionary perspective you might get some insight in this interesting question. Given that Oxygen is one of the best acceptor of electrons, those cells that developed oxygenic respiration pathways were lots more efficient (around X20 times) competing for resources than anaerobic ones. When O2 concentrations in the atmosphere increased (thanks first to cyanobacteria) those cells could specialize, divide functions and become multicellular organisms. Of those, the heterotrophic ones are the Animalia. After the NEO atmospheric o2 concentrations reached actual levels almost no anaerobic organisms could compete in oxygenic environments with the ones that respired o2....so yes, the 3d hypothesis seems the correct one. Increasing o2 levels gave a boost to the radiation and increase in complexity of active and diverse animals.
It's not entirely correct to say (at 17:02) that humans cannot anaerobically metabolise. Anaerobic respiration happens in cells when oxygen levels are low (usually in muscle cells during hard exercise). Glucose is converted into lactic acid and ATP.
Great question! And such an important point that I should've made more clear in the video, thanks for asking this! The two major reservoirs of C on Earth is oxidized C (CO2 and CH4 in the atmosphere) and reduced C (organic carbon). Organic is oxidized to CO2 by oxygen respiring organisms like ourselves, and CO2 is reduced back into organic C by photosynthesizing organisms. This cycle is pretty much in a good balance, but some processes can throw this C cycle out of balance, for example large outputs of oxidized CO2 from volcanism, human activity, methan hydrate melting, etc. These processes cause an increase in oxidized CO2 and CH4 in the atmosphere. But an increase in OC burial rate can tip the balance the other direction because the the buried OC escapes oxidation, thus, decreasing CO2 in the atmosphere and increasing oxygen (because the oxygen is not being used to oxidize that OC to CO2). Thes cycles are much more complex in reality, but this inverse relationship between oxygen and C is one of the major things that has controlled climate change events through Earth's history! ;D
@@GEOGIRL Rachel, that was brilliant! You’ve talked so much about burial OC increase atmospheric O2. Now, I finally understand. Thank you for the involved explanation.
Oh interesting, I got a comment about this a while back but before then never knew this was even a consideration haha. It's my understanding that, no, oil cannot be formed abiotically because oil is organic in origin. I cannot think of a scenario that would abiotically form oil (if there is one, the product would no longer be 'oil' based on the definition of oil haha). Hope that helps ;) This is not my field of research, so if there is something that I am missing or research that's said otherwise, please send me the articles! Thanks ;D
Do you see any parallels between the emergence of oxygen and the corresponding radiation of flora and fauna with the emergence of the hydrogen economy, as it displaces the long-standing combustion economy? If so, what kind of forecasts could be made?
Wow another Animals 😅 Btw Im curious how rocky mountains are formed and all surounding areas like Banff and Jasper National park, Im a mountain lovers 😉
0:23 I love it. Patent it. It's gonna be the new hot thing. Move over, "non-avian dinosaurs" here is "animalution". Seriously. You could print that on a T-shirt and you got merch for your subscribers.
"When animals originated and when they diversified are separate questions, meaning either one or both of these phenomena could have been decoupled from oxygenation. " I find this quite normal as 1st: the oxygenation process took at least 250 My to reach 10% PAL. Then animals appeared (by the way sponges (Porifera) is a good example here as they are the most primitive and least active simple animals. 2nd: only when O2 concentration increased was the "Oxidant atmosphere niche" worth the "manufacture and refinement" of a full metabolism based on cellular oxidative respiration by natural selection. Then animals diversified and got more complex.
Can pyrite replacement fossilization show the vascular structure of flora and/or fauna? The reason I ask is that the recent mineral sample I found has regularly shaped inclusions ie. octahedral crystalline structures, triangular, and pyrite with holes apparent throughout a thin piece I made. There is also a structure that has a "stem-like" piece with barb-looking objects all over the outside of the said object. I am told by other geologists & meteorologists that metallic meteorites do not have holes. This particular non-metallic object is either a plant part or an insect part or a microbe of some sort. The "spikes "are crescent-shaped, thicker at the stem have an extremely sharp point, and they all point in one direction. The rock overall is a jumbled mess of materials. It has a peridot in the structure. Three to four different metals. Silver, gold, pyrite, and chalcopyrite are four I recognize. They are in what appears to be quartz. There are also garnets, azurite, and malachite features. Any educated guesses?
'... we are animals and we cannot anaerobically metabolise." Erm anyone who's ever had a buildip of lactic acid from lactic acid fermentation anaerobic respiration would beg to disagree with that contention. We cannot survive based on that form of respiration but we very much CAN undertake it.
Kinetic energy... I thought that was movement? Is temperature related to movement? Whhhaaat... do the water molecules friction on each other do something to temperature? Sorry if this is a dumb question 😂💖
Not a dumb question at all!! And actually you got it almost exactly right! It’s just about particle motion :) The higher the T the faster particles move and thus, the higher the kinetic energy.
@Kerri this is the very essence of one of the most important parts of statistical thermodynamics: relating microscopic properties to macroscopic bulk properties of materials. It's not just translation (how fast something moves) that can have a temperature. Rotation and vibration do as well. Again if you think about it these are all down to how fast something moves, whether the whole molecule or the molecule about its axes or the molecule's constituent atoms with respect to each other.
@David Newton ohhhh thank you for the extra nuance! This is beginning to remind me of a book I read once called The Dancing Wu Li Masters by Zukav with all this spin going on lol maybe the grand unifying theory will be found through geology...
What chemicals in the atmosphere block harmful cosmic and sun radiation? Did I miss that in the video? Ozone? Earth's magnetic field? Molecular oxygen has to be there for it to form. She seems to indicate oxygen was not that important and therefore life evolved even though there was more radiation than today perhaps from space.
Yes, as I mentioned, ozone wouldn't have formed a thick enough layer in the atmosphere to protect life from harmful radiation until O2 concentrations hit about 1% present day levels. Before then, there are ways that early phototrophs (photosynthesizing organisms) protected against UV (which I talk about in this early phototroph video: th-cam.com/video/x5wVW3OGg7c/w-d-xo.html) and the other organisms (chemotrophs) just ate the phototrophs and the products of the phototrophs (or inorganic material) so they already lived deep enough in the ocean to be protected from harmful radiation. Hope that answers your questions! ;)
@@GEOGIRL I appreciate you are making these videos. As an earth science teacher in high school, I was following another lady who was doing videos like you but quit or don't have near as many. I am also looking to follow people in the sciences I teach at the high school for earth/space, astronomy, and chemistry.
Could it be that during the GOE and NOE events there was also a coinciding end of the snowball-earth period, that resulted in a massive dump of "food" for the micro-organisms that produced the oxygen?
So the question is not why the animals started to rapidly evolve but why did complex ecosystems started to evolve. Oxygen is important for its role in processing energy so ideally a study should focus on the energy cycles themselves. Maybe there is an energetic threshold for a complex ecosystem. This would also be more helpful for astrobiology but it would require identifying energy processes using alternatives to oxygen.
Animalution needs to be a thing Rachel 😂
Agreed! Let's make it official LOL Maybe I'll make some 'Animalution' merch hahaha
Could be a name for a TH-cam channel
@@GEOGIRL apakah kamu sadar bahwa kamu itu cantik 😊
I love how precise you are with your languag., So many channels that talk of anything related to science use ambiguous language, confuse theory with fact or just straight out decieve.
Another great video.
Thank you so much! This means so much because I was not always good at doing that, but have really worked on improving my concept clarity and making sure I thoroughly explain things that are ambiguous :)
Thank you Geomommy for blessing us with another informative Biogeochemophysical vide
Of course! Gotta love biogeochemophysical science! ;D
Another concise and well structured video, great work, and really interesting too.
I have had the pleasure of seeing Ediacaran fossils in their native habitat - the Ediacara Hills in the state of South Australia, and the type location, Brachina Gorge. I like to think they are the Hipsters of the geological record, as they were already around before life got popular in the Cambrian.
Another awesome video, your enthusiasm and positive fervor for your field of study is really empowering. The way you explain and elaborate everything in a some what simplified way is really helpful. For someone who hasn't been able to finish as much school and education as I'd like to yet these videos are truly great. Thanks for your uploads
Thank you so much! I am so glad you enjoy my uploads even without being in this field, and I am glad my passion is translated through my discussion on this research, it is truly so exciting to me! ;D
I too am of the uneducated Riff-raff that enjoys a bit of biogeochemistry now n then! Nice to meet you David Brown 😊
@@GEOGIRL 1st time watching ur videos....I'm very impressed! Excellent and enthusiastic explanations!
@@markb8468 Thank you so much!! :D
@@GEOGIRL jangan terlalu dan tak perlu bersolek sana sini jika kamu itu sudah cantik 😊
Tapi apa daya jika memperhatikan kehidupan wanita.
RUWET
This is by far the best channel for paleontology. No frills, just good information.
Thank you! :D
@@GEOGIRL kamu berterima kasih kepada siapa.
Ajari saya cara untuk berterimakasih kepada wanita 😊
Oxygen. This is so cool. By the way, I have difficulty communicating because I had a stroke in Broca’s area, the part of the brain that controls speech. 2/8/2021 but I lived again. (My wife helped me compose this.)
I'm SO proud of anyone who is the courage to face having to relearn what we thought we would NEVER have to relearn -- walking, chewing, speaking. I commend you! And I'm glad you have such a partner who cares so much. Hang in there! ❤
This is a fascinating topic and this video provides an insightful, detailed and balanced analysis. Great job! Thank you!
I think we need to be cautious of looking for a single driver in the long term evolution of such a complex and interdependent system. Also, we should be warry of deriving too much guidance from analogy to modern conditions. After all, there is a strong correlation between ice cream consumption and shark attacks, though this correlation has an independent geographic limitation since it is not observed in St. Louis. 🙃
Couldn't agree more with everything you said! ;)
Fascinating topic. I've always been interested in the fact abiogenous seems to be easy as life emerged so soon after earth's formation and yet it took forever for complex multicellular organisms to evolve. I had just assumed this was do to the need to build up oxygen in the atmosphere. Your video shows, like many things in science, the underlying causes are much more complex.
Yes, I think there are many times we simplify things down to a level that is almost incorrect (I am guilty of this as well, especially when I am talking about things outside of my expertise). But for this video, because it is in my field of research, I really wanted to lay out the complexities of everything involved because 1. I think it's important for us scientists and science communicators (including myself) to address the unknowns, and 2. it is just so interesting (at least to me)! ;)
A study published this month (July 2024) in Nature Ecology & Evolution used analysis of genetic mutations and what we know about the normal mutation rate to put LUCA at 4.2Gya -- this is the Last Universal Common Ancestor to all life known on Earth today. So around 350 million years after the final formation of the Earth! Yet now we've also discovered so-called "dark oxygen" on the ocean floor that's produced by geological processes! These little polymetallic nodules generate electricity and they believe are causing the molecular oxygen via electrolysis of the water.
I've been enjoying with this series, but never seen her so happy, smiley face here & there (giggling?). That may mean herself enjoyed & satisfied with this footage as we viewers did. Seriously, this could be one of the best presentations in every aspect. Great enthusiasm & effort is tangible, as summarized in 20 odds minutes is a masterstroke. Well-structured narration is informative & effective more than usual, which provides sources for thought! She handled this very intriguing, complicate & fascinate subject pretty well, simple & clear. This video shares a positive view on the link between oxygen level & animal evolution. On the other hand, to take rising oxygen level for villain or destructive factor is another version of earth history, which I watched recently. That was equally interesting & very high standard.
Even 1% of increase should have had enormous impact, given the large scale, if not planet level! This oxygen issue reminds me of appearance of gigantic insects.
So inspiring it was, here's a homework for you: about fluctuations of oxygen levels. How about potential influence by groups of newcomers, oxygen consumers? How to reach equilibrium? Did suppliers of oxygen get any benefits from them? You may need sequels. Many thanks & keep it up, geo giggle girl!
Cool presentation!
I have a few thoughts/questions:
1. With regards to temperature and oxygen, an increase in T would lower the solubility of oxygen in the water; so there’s synergy.
2. In my understanding, Cambrian animals were benthic or demersal. These environments tend to have much lower oxygen diffusing from the atmosphere and more reducing conditions due to chemical interactions with the sediment.
3. In relation to the above, as oxygen levels increased, iron dissolved in the water column and in the interstitial spaces of the sediment would remove lots of oxygen.
4. Functional anaerobic microbes wouldn’t decompose organics as quickly during periods of low oxygen, leading to a buildup in the shallows. When oxygen levels increased to the point where the microbes switched to aerobic respiration, their decomposition rate would increase by an order of magnitude, flooding the system with nutrients and dissolved organics (like the Gulf of Mexico “Dead Zone”), while simultaneously sucking oxygen from the water column.
Are those factors being considered?
Thanks!
Hmm Ive seen quite a few genetic algorithms simulating very simple evolution, say to construct clocks once you introduce some basic parts and attractions between them. A common pattern would be the very rapid evolution of a comparatively simple mechanism then a long time of no real developments (The age of the pendulum.) then the very first most basic clock mechanism would appear and there would follow an explosion of rapidly more accurate and sophisticated clocks with multiple hands etc.
Obviously life is many orders of magnitude more complex, but I dont think that difference in complexity would inherently rule out something similar occurring in nature? Especially with the vastly greater time scales involved. I.e. If a more complex life form would have an evolutionary advantage in any case, would there need to have been any external change to trigger that development? Couldnt it have just been a product of the difficulty in making that evolutionary leap regardless of the variations in temperature, oxygen etc.?
It's a question of having sufficient energy to power a mass of cells. There are many metabolic pathways invented by prokaryotes, but most of them yield barely enough energy to run one cell. Oxygen metabolism, which is what animals use, yields by far the most energy. Complexity can't evolve without the extra energy to create specialized cell components and cell types.
Do we know what the atmospheric pressure was in the past, and how does atmospheric pressure affect this oxygen threshold? I would think at higher pressure it would be easier to breathe at the same % levels of oxygen.
That is a GREAT question! I have generally assumed that atmospheric pressure has remained relatively constant through Earth's more recent history (pretty much everything after the Hadean which ended ~4 billion years ago), but now that you say that I am not sure I have actually ever read any papers on atmospheric pressure through geologic time, so I will have to look into that! Thanks for the comment! I hope someone more knowledgeable than me on this topic can reply to this thread and enlighten us ;D
Maybe sharks like ice cream has anyone tested to see? More ice creams on the beach, sharks come in closer sniffing that vanilla, closer interaction of humans and sharks increases frequency of attacks. Maybe there’s a preference for some flavours, eg cookie dough, or choc chip, research into this could be useful in reducing shark attacks- I’m going to try and get a research grant, obviously a lot of it would need to be spent on ice cream but I’m prepared to eat it in the name of science.
good one thats a funny correlation example nigel 😂
Very interesting indoctoration of oxygen and Co2 impacts, on the evolution of life... I would love to see a video of your findings, on Co2 emissions, and it's impact on the earth's response,, both positive and negative... I believe there still hasn't been enough study to show direct links on the effects of present 'climate change', with regarding the increase of Co2 emissions in our atmosphere... There's a lot of theories out there,, but no factual data to explain whether or not our planet is 'naturally' going through a geological transformation on it's own,,, or proof or data to show that the rise of Co2 emissions is directly impacting this transformation... I truly believe that the more educated and informed we humans can become in discovering the 'facts',,, the better we become to making crucial adjustments in responding with our technologies going forward...
Presentation was a breath of fresh air
Thank you!
Great video as always. I am impressed by the amount of research you do.
Do we know the genetics that enable low oxygen capable animals to survive with little to no O2? If we do, we should be able to get an idea of the relative age of these genes. By we, I mean people who know things about genetics. Not me.
It strikes me that the special thing about animals is movement, which requires more energy than being stationary, and therefore seems to require aerobic metabolism. Sponges don't move, and seem to get along better than most animals in the absence of oxygen. IIRC, the larval stages of sponges are mobile. This suggests an hypothesis: Sponges developed during a era of unstable oxygen levels, only producing larvae during periods of high oxygen level, when there was a chance the larvae could settle and mature before the oxygen levels fell. Animals that couldn't sit still during low-oxygen periods had to wait until the NOE.
Not me either lol! I thought about including something about genetics in the video, but I just don't know (or understand) enough. Funnily enough, when I was an undergrad one of the avenues I considered was genetics, but then I realized it is super complicated lol
I hope somebody else that knows about genetics can answer this comment better than I can haha ;)
Many animals have transcription factors called HIF-1("hypoxia-inducible factors”) that regulate oxygen consumption in low oxygen conditions. But interestingly the most basal animals, sponges and ctenophores, lack HIF-1. HIF-1 appears in Parahoxazoa (bilateralians, placazoa and cnidarians). So this suggests that sponges and ctenophores evolved at lower oxygen levels, while the Parahoxazoa split off from them and evolved in higher but fluctuating O2 levels. Cf Wikipedia "Hypoxia-inducible factor".
Thus sponges and ctenophores may have evolved earlier in the Neoproterozoic (Cryogenian? or early Ediacaran?) than the Parahoxazoa (later Ediacaran?)
@@ellenmcgowen Interesting. Thank you.
@@GEOGIRL yes complicated and there's math involved. I have an old math injury, so...
@@ellenmcgowenvery interesting thx 🎉
The great oxygen catastrophe is the most interesting phase of the history of the planet.
I think the atmospheric conditions and ozone layer may be the biggest factor. Also the sun's radiation output and orbit of earth affected th ability of complex biology to occur.
Thanks geo girl great presentation
Thank you! So glad you enjoyed it ;)
A very interesting video! The crude picture I had was that the deep ocean was euxinic during most of the Proterozoic (the Canfield ocean), but that the breakup of Rodinia allowed ocean circulation changes that oxygenated deep ocean waters, allowing faunal assemblages to establish themselves during the Ediacaran. Then this oxygenation of deep ocean waters intensified in the Cambrian. That is probably grossly oversimplified... for one thing, I'm foggy about the details of ocean current changes during that period.
The general picture I have of the development of life on Earth is that plate tectonics took a *long* time to get started and complex life probably depends on it -- so one question for the habitability of super-earths is what happens to plate tectonics as you make a terrestrial planet bigger or smaller?
What happens when you consider that minimum oxygen levels are not a trigger, but a condition? Even when conditions are met, evolution is still very much limited by chance. Things can happen, but they don’t necessarily do.
Exactly! That's what I meant by 'it was a prerequisite but was it a cause?' But then we also have to think that maybe it kinda was a cause because maybe evolutionarily, everything was ready to go but couldn't until oxygen rose... But ultimately, I think we've learned that the question isn't 'did oxygen cause animal radiation' but rather 'did it prohibit it for the long period before the ediacaran/cambrian?' And if it wasn't the major prohibiting factor, maybe something else was limiting... I mean there are so many possibilities so it's hard to look at it like one thing was the 'major' thing, but rather it was many things all at once. It's a difficult question for sure! But also a super facinating one ;)
Animalution...I like it. Might as well use it.
Hahah I actually like it too lol
Great video. I learned a lot. It's absolutely fascinating.
Thanks. I have to admit that I had to switch my listening into what I call "Lecture Mode". It was very interesting.
Question: How long do you think that it took to oxidize all of the materials that we now find as oxides? It obviously would have taken much quicker than 1.5 billion years.
That's a great quesiton, but I think it is impossible to say because compounds that became oxidized after the initial increase in oxygen were continually reduced by both abiotic and biotic processes. Biology itself is a cycle of oxidizing and reducing metabolisms, so the presence of life during these oxygenation events prevents us from estimating the amount of time it took for everything to become oxidized because technically it never did. Even today, reduced compounds exist and fuel the disequilibrium that allows life to go on. The day that everything on earth becomes oxidized is the day that life on earth is no longer possible, at least life as we know it ;)
Edit: if you are asking more so how long it took for oxygen to oxidize the most readily available things, like reduced iron for example, then for that I would say it is also difficult to say haha! Because the GOE rose oxygen to near modern levels but then pwent back down again and a lot of the Fe that was oxidized in the process (that formed BIFs) became reduced again by the abundance of sulfide in the ocean from sulfate reducing bacteria, so it was a fluctuating trend rather than a straight line so a 'how long' is not representing a linear trend if that makes sense... The reducing bacteria and other reducing processes greatly interferred with this trend. For that reason, it is completely reasonable to say that it took 1.5 (or over 1.5) billion years for oxygen to oxidize all the minerals that we recognize today as oxides. I would say a more accurate answer is 3.5 billion years. Because technically oxygen was initially produced as early as 3.5 (or earlier) billion years ago, and ever since then it has slowly been oxidizing everything on earth (with downward fluctuations of course) until we reached our current senario today. I hope that makes sense (I feel like that was really rambly but that's the best I can do at the moment haha). :)
@@GEOGIRL Your answer was perfect......Real answers are often slightly ambiguous.
So, I know I'm old now by finding out my colleague and former roommate is now back at UTEP as an assistant professor. Dr. Jay Chapman - you should definitely get with him on anything structural, my friend. He's god tier at that shit. I will also definitely be trying to stop by campus and visit him on the 9th-10th of Feb. Also need to check in on Libby and Phil. Cheers!!
That's so cool! Actually Jay recently moved into the office right next to my lab, so I am well acquainted with him, he's great! Also love Libby and Phil! I hope you have a great visit ;D
Rachel, one of your commenters brought up a separate topic of abiotic oil. I concur with your response…but what can you tell me about Titan. Apparently a Lake Ontario-sized lake has been discovered on Saturn’s moon Titan that is composed of hydrocarbons, specifically liquid ethane. By some estimates, the contents of this lake could be equivalent to as much as 9 trillion barrels of oil. Even NASA suggests that Titan could have “hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth.” What do you make of this…it would obviously be abiotic…hogwash or reality?
Oh see this is a brilliant example of something I didn't think of! I think that Titan is a whole separate situation because photochemistry has allowed organic chemistry to go crazy there given its abundance of methane to begin with. This feels like when I tried to explain to my mom that I was taking an inorganic biochemistry course and she was like isn't that contradictory? haha I think the two scenarios (Earth and Titan) are very difficult to compare, so is abiotic 'oil' possible? Yes, on Titan, but not on Earth... Although I am not sure if what is being formed on Titan would count as what we define as 'oil' on Earth... I just looked it up and they are careful to say that Titan has abundant "liquid hydrocarbons" rather than saying "oil" so I am curious what the composition is and if it is made of much simpler organics... But I am no Titan expert, so I can't answer this question intelligently haha, I hope a Titan expert will eventually chime in on this thread! ;D
Yes, I agree, not oil as we earthlings perceive it….but, nonetheless, a form of hydrocarbon not related to biological origins. So fun to ponder all this. So many unknowns. I do think your response was intelligent and logical. Thanks also for your thought provoking video on oxygen and it’s relationship to early evolution of life on earth.
Great video. By the way, Animalution sounds like a great name for a band. 😂
Worth mentioning:
en.m.wikipedia.org/wiki/Spinoloricus_cinziae
A lorciferan that needs no oxygen at all.
Of course it is highly derived, and doesn't represent a basal condition.
Still, the minimum O2 concentration requirement for animals seems to be 0%
Very cool! Yep, as I mentioned, there are plenty of animals now found to either not need oxygen at all, or to only use it when it is present, so the limit is kind of obsolete. Although, as you mentioned, we need to make sure we are looking at basal rather than derived traits in order to use this as an argument for early animals. :)
I think I will always remember the correlation between ice cream sales and shark attacks...hahaha
Animalutiom is now a new awesom word! As you know I'm a Precambrian rock guy and life isn't my thing. So I look forward to these.
I have a request. Feel free to ignore. Can you do one on the atmosphere evolution from the Hadean to Cambrian? Along with atmosphere thickness thru time?
Another, probably related question: is there a relationship between increased oxygen and the evolution of hard parts? Edicaran biota did no biomineralization. Cambrian biota biomineralized like mad, facilitating the beginning of a predation/protection arms race. Is the invention of hard parts related to increased availability of dissolved oxygen? Related to availability of dissolved calcium due to increased glacial weathering? Other? Paleobiogeochemistry is pretty interesting.
Well I assume the formation of hard parts requires more energy and thus, higher oxygen levels for animals to carry out this process. Also, you are right that the increased weathering at the time increased the Ca flux to oceans, so there was a perfect storm to cause the evolution of hard parts around this time. However, there sudden appearance and radiation at the Cambrian is puzzling to me given that these conditions should've been met in the Ediacaran. So I will look into it and make a future video! I imagine maybe it had something to do with the time needed for natural selection to led to hard part favoritism, or maybe the stabilization of well-oxygenated zones in the ocean for benthic ecosystems to gain more energy. Not sure, but I will figure out whatever we know or think and make a video! Very great topic, thank you for this comment :D
To quote.... well, lots of people.... its never just one thing.
Wonderful presentation. Two comments: Nick Lane's 2002 book "Oxygen, the Molecule that made the World" covers some of the same ground, but does not explore this particular chicken-or-egg aspect. The second is a whoopsie... At 8:42 you said that primary producers get oxygen from CO2. They don't .. The released oxygen comes from water. The CO2 goes into the sugars they're making for themselves. It's a nuance, but it's important.
Yes, I am fully aware they use the CO2 to make biomass and split water to make oxygen, I meant to suggest that they use the CO2 and light to gain energy which they use to split the water molecule rather than suggesting that they actually make oxygen from CO2 alone, so my bad! Sometimes I tend to skim over things assuming people will know what I mean, but you're completely right I should've clarified that so people don't get the wrong impression, but thank you for clarifying here in the comments in case people are curious! ;) Also, yes, I love Nick Lane's book about oxygen as well!! ;D
I am not sure that purely the fact that today, we have animals which tolerate very low oxygene levels, invalidates OCH. We also have whales and dolphins, which never go on dry land, but for their evolution, dry land was necessary. Maybe high oxygene levels were necessary to kickstart animal evolution, but later adaptations allowed animals to deal with lower oxygene levels too.
Ms. Geo Girl, No one doubts your genius and if I criticize it is meant to be completely constructive because I think you are brilliant. Since you are not speaking to impress a grad-student or a professor, you might slow it down a bit and use a few pauses for dramatic emphasis. Evolution is a wondrous story and speculation of life on other planets is even more exciting. You might be sharing your knowledge with ordinary people who could not afford college or had a different major but are really interested.
To eliminate lapses, pauses and stumbles is a practical consideration to tighten your clip up and make it presentable. However, by removing every little breath and pause makes you sound less human and your talk homoginized. Don't follow the text book so closely and make it a story that inspired you personally and excites you about science and evolution. Slow it down a little and have some one in theater arts or lecturing, critique your work. Feel free to ignore them if they advise something that is not your style. My simple rule is, Be flexible..
Again I will say I think you are brilliant and thank you for your clips.
Thank you for the tips and support!
Other scenario : Few if any pre-Edicaran soft bodied fossils formed. They MAY have been around, but how can we know ? The human lineage certainly has expanded greatly over my lifetime due to fossil discoveries. Those "explosions" may have been just a continuous rate of evolution, marked by rare fossil deposits. I wonder what the basal jellyfish ancestor looked like ? Bet it almost never fossilized, and most of those rocks are long gone anyways.
FINALLY a geology nerd channel!
YES ;D hahaha
you’re great! : )
Thank you! ;D
I learned that there was a GOE and a NOE. I did not know that.
All Geo Girl videos are good but they are especially fun when they involve freaky prehistoric creatures. 😊 🦠
Excellent!
This is awesome! I wonder if increased levels of oxygen is a self sustaining loop in the biosphere. Complex life thrives on O2, so it would be advantageous for them to establish systems that maintain high levels of it.
Well presented and thoughtful.
Thanks a lot for creating & sharing - highly appreciated! BTW 4:40 love that quiet sense of humor: just looking at these most adorable curves alone would have made my evening...
Thanks haha! I looked up correlation is not causation to find graphics for that slide and when I saw that graph I knew it was perfect lol
It seems what they dined on would have made a difference because the larger virus of past may have optimized living critters?
Rachel, I'm curious about your procedure for producing these videos. Do you write a script? Or do you just make the slide show and use them as an outline, but talk off the top of your head? Do you make many mistakes while you're talking that require you to cut and edit your video? Or do you do it all in one take?
I just make the slide show and use that as an outline. I kind of think about what exactly to say as I make the slide show and then when I film I speak from my head, but thankfully I know that I can edit so sometimes when I film I try a few different renditions of each concept explanation and then pick my favorite while editing and just cut out the rest. :) This may change in the future but that’s currently just what comes most natural to me when producing these :)
So now we know that the more ice cream we buy, the more we are attacked by sharks.
Well that was the main point of the video ;)
It was an ironic joke about confusing correlation with causation - something I see constantly in so many places.
I think that from an evolutionary perspective you might get some insight in this interesting question. Given that Oxygen is one of the best acceptor of electrons, those cells that developed oxygenic respiration pathways were lots more efficient (around X20 times) competing for resources than anaerobic ones. When O2 concentrations in the atmosphere increased (thanks first to cyanobacteria) those cells could specialize, divide functions and become multicellular organisms. Of those, the heterotrophic ones are the Animalia. After the NEO atmospheric o2 concentrations reached actual levels almost no anaerobic organisms could compete in oxygenic environments with the ones that respired o2....so yes, the 3d hypothesis seems the correct one. Increasing o2 levels gave a boost to the radiation and increase in complexity of active and diverse animals.
It's not entirely correct to say (at 17:02) that humans cannot anaerobically metabolise. Anaerobic respiration happens in cells when oxygen levels are low (usually in muscle cells during hard exercise). Glucose is converted into lactic acid and ATP.
Rachel, how does OC burial increase surface oxygen, like what you've said "Faecal pellets increase particle settling & OC burial rates (increasing surface O2)? Thank you.
Great question! And such an important point that I should've made more clear in the video, thanks for asking this!
The two major reservoirs of C on Earth is oxidized C (CO2 and CH4 in the atmosphere) and reduced C (organic carbon). Organic is oxidized to CO2 by oxygen respiring organisms like ourselves, and CO2 is reduced back into organic C by photosynthesizing organisms. This cycle is pretty much in a good balance, but some processes can throw this C cycle out of balance, for example large outputs of oxidized CO2 from volcanism, human activity, methan hydrate melting, etc. These processes cause an increase in oxidized CO2 and CH4 in the atmosphere. But an increase in OC burial rate can tip the balance the other direction because the the buried OC escapes oxidation, thus, decreasing CO2 in the atmosphere and increasing oxygen (because the oxygen is not being used to oxidize that OC to CO2). Thes cycles are much more complex in reality, but this inverse relationship between oxygen and C is one of the major things that has controlled climate change events through Earth's history! ;D
@@GEOGIRL Rachel, that was brilliant! You’ve talked so much about burial OC increase atmospheric O2. Now, I finally understand. Thank you for the involved explanation.
GEO Girl, off topic, but do you think abiotic oil is a thing? Thanks!
I’ve been bugging about that one haha
Oh interesting, I got a comment about this a while back but before then never knew this was even a consideration haha. It's my understanding that, no, oil cannot be formed abiotically because oil is organic in origin. I cannot think of a scenario that would abiotically form oil (if there is one, the product would no longer be 'oil' based on the definition of oil haha). Hope that helps ;) This is not my field of research, so if there is something that I am missing or research that's said otherwise, please send me the articles! Thanks ;D
Do you see any parallels between the emergence of oxygen and the corresponding radiation of flora and fauna with the emergence of the hydrogen economy, as it displaces the long-standing combustion economy?
If so, what kind of forecasts could be made?
Good stuff!
Very good video 😀✨✨👏
Animalution.... What a great concept.
we need more than 1% oxygen to get proper Animalution .
Wow another Animals 😅 Btw Im curious how rocky mountains are formed and all surounding areas like Banff and Jasper National park, Im a mountain lovers 😉
0:23 I love it. Patent it. It's gonna be the new hot thing.
Move over, "non-avian dinosaurs" here is "animalution".
Seriously. You could print that on a T-shirt and you got merch for your subscribers.
YES! I am planning on doing merch with it haha, so I'll post on the community tab when it's up! ;)
Doesn't she speak well? Really great public speaker.
She sounds like a farmer....
Thanks!
Thanks so much! :D
"When animals originated and when they diversified are separate questions, meaning either one or both of these phenomena could have been decoupled from oxygenation. " I find this quite normal as 1st: the oxygenation process took at least 250 My to reach 10% PAL. Then animals appeared (by the way sponges (Porifera) is a good example here as they are the most primitive and least active simple animals. 2nd: only when O2 concentration increased was the "Oxidant atmosphere niche" worth the "manufacture and refinement" of a full metabolism based on cellular oxidative respiration by natural selection. Then animals diversified and got more complex.
Can pyrite replacement fossilization show the vascular structure of flora and/or fauna?
The reason I ask is that the recent mineral sample I found has regularly shaped inclusions ie. octahedral crystalline structures, triangular, and pyrite with holes apparent throughout a thin piece I made. There is also a structure that has a "stem-like" piece with barb-looking objects all over the outside of the said object.
I am told by other geologists & meteorologists that metallic meteorites do not have holes.
This particular non-metallic object is either a plant part or an insect part or a microbe of some sort.
The "spikes "are crescent-shaped, thicker at the stem have an extremely sharp point, and they all point in one direction. The rock overall is a jumbled mess of materials. It has a peridot in the structure. Three to four different metals. Silver, gold, pyrite, and chalcopyrite are four I recognize. They are in what appears to be quartz. There are also garnets, azurite, and malachite features. Any educated guesses?
'... we are animals and we cannot anaerobically metabolise."
Erm anyone who's ever had a buildip of lactic acid from lactic acid fermentation anaerobic respiration would beg to disagree with that contention. We cannot survive based on that form of respiration but we very much CAN undertake it.
Yes, of course, I am sorry I should've been more clear that we cannot 'survive' on this type of metabolism ;)
Animalution... I like it...
Kinetic energy... I thought that was movement? Is temperature related to movement? Whhhaaat... do the water molecules friction on each other do something to temperature? Sorry if this is a dumb question 😂💖
Not a dumb question at all!! And actually you got it almost exactly right! It’s just about particle motion :)
The higher the T the faster particles move and thus, the higher the kinetic energy.
@GEO GIRL oh wow cool that's awesome omg im starting to connect the dots 😄 😂 I love you so much 💖
@Kerri this is the very essence of one of the most important parts of statistical thermodynamics: relating microscopic properties to macroscopic bulk properties of materials.
It's not just translation (how fast something moves) that can have a temperature. Rotation and vibration do as well. Again if you think about it these are all down to how fast something moves, whether the whole molecule or the molecule about its axes or the molecule's constituent atoms with respect to each other.
@David Newton ohhhh thank you for the extra nuance! This is beginning to remind me of a book I read once called The Dancing Wu Li Masters by Zukav with all this spin going on lol maybe the grand unifying theory will be found through geology...
This is an amazing video.
was the last common ancestor to animalia and fungi multicellular? Could charnia be one of these stem organisms?
Dickensonia was found to contain cholesterol, so it was an animal, I wonder if the fungi genome contains genes that can produce cholesterol?
Yeast probably refutes this idea now that I think about it.....
Maybe the holes are burrowing creature holes? The mud would have to be replaced by pyrite...that doesn't seem likely
What chemicals in the atmosphere block harmful cosmic and sun radiation? Did I miss that in the video? Ozone? Earth's magnetic field? Molecular oxygen has to be there for it to form. She seems to indicate oxygen was not that important and therefore life evolved even though there was more radiation than today perhaps from space.
Yes, as I mentioned, ozone wouldn't have formed a thick enough layer in the atmosphere to protect life from harmful radiation until O2 concentrations hit about 1% present day levels. Before then, there are ways that early phototrophs (photosynthesizing organisms) protected against UV (which I talk about in this early phototroph video: th-cam.com/video/x5wVW3OGg7c/w-d-xo.html) and the other organisms (chemotrophs) just ate the phototrophs and the products of the phototrophs (or inorganic material) so they already lived deep enough in the ocean to be protected from harmful radiation. Hope that answers your questions! ;)
@@GEOGIRL I appreciate you are making these videos. As an earth science teacher in high school, I was following another lady who was doing videos like you but quit or don't have near as many. I am also looking to follow people in the sciences I teach at the high school for earth/space, astronomy, and chemistry.
😎
Could it be that during the GOE and NOE events there was also a coinciding end of the snowball-earth period, that resulted in a massive dump of "food" for the micro-organisms that produced the oxygen?
Animolution as opposed to botanolution. 🤣
Can you give me about Cambrian explosion how that made happened!!
So the question is not why the animals started to rapidly evolve but why did complex ecosystems started to evolve.
Oxygen is important for its role in processing energy so ideally a study should focus on the energy cycles themselves. Maybe there is an energetic threshold for a complex ecosystem. This would also be more helpful for astrobiology but it would require identifying energy processes using alternatives to oxygen.
I feel like I waited 21 minutes to hear why O2 is important but still don't know. My guess is that that the instability of oxygen as an element.
Controversy...... Oxygen brought man to life.
Wow lol
Yay stromatolites!!! LOL
You and I are on the same wavelength lol
Oxygen is SO controversial. We should cancel oxygen
Je suis amoureux de ton cerveau❤
Post hoc ergo propter hoc...
Please talk slowly...slow down
You can change the playback speed in settings
You need more Subscribers. You should ask for a Collab with @Tierzoo @Miniminuteman or @LindsayNikole
OMG, Rachel, now we've discovered abiotic O₂ synthesis on the ocean floor! Is this going to change all of this science?
I have a video on this coming Sunday! :D
@@GEOGIRL How do you fit SO much awesome in such a tiny space! 🥰 I haven't read the paper, only a news article about it; it's in Nature Geoscience.
Excellent!
Thank you! So glad you enjoyed it ;)
Thanks!
Thanks so much! I am so glad you enjoyed the video :)