Prebiotic Earth: What Earth Was Like Before Life / First Atmosphere, Oceans, & Landmasses | GEO GIRL

[@mspicer3262]

For additional context on ocean acidity early on, battery acid has a Ph of 0.8, so with a Ph less than 1, the oceans were basically the equivalent of battery acid. That's a scary thought.

[@GEOGIRL]

Thanks for the context! Isn't that crazy!! 🤯I am very happy it rose since then haha

[@kunalnalawade7845]

It's mind-blowing how earth used to be before life started to appear. It's one of my favourite research fields and there is a lot that could learnt here. This video is really informative and you explained it nicely. My only question is how this video does not have more views. Keep up the good work

[@GEOGIRL]

Haha, that is the one question I cannot answer, but I hope in time they will accumulate ;) Thanks for the comment! I agree, I think this stuff is SO cool! :D

[@AmahMasBoy]

This video was randomly recommended to me and I don't regret it. Solid video, Good Job.

[@GEOGIRL]

Thanks so much! Glad you liked it :D

[@hensontauro]

Just found your channel in my recommendations. I really appreciate you making content like this. It's amazing how much effort you've put into it.

[@GEOGIRL]

Wow, thank you so much! I really appreciate that you appreciate the effort I put into these ;)

[@KerriEverlasting]

@@GEOGIRL I really appreciate the the appreciation of the appreciation of the effort that was made.

[@catchingphotons]

Hey Rachel! Thanks for creating this very interesting and cool videos!! You did a great job in breaking the complex information down for "non experts" like me! Good job!! Please continue creating content like this! Clear skies! -Chris

[@GEOGIRL]

Thank you so much! It means to much that you think I do a good job with that because I am so integrated into the academic world that I question whether I am doing a good job making the information understandable to everyone and not using too much jargon and stuff, so I appreciate your comment greatly! :) -Rachel

[@exiledkenkaneki701]

Hey just here to say that i am interested in life forms that existed before ours, specially the ice age is one of my fav because of some games i used to play, your content seems fun to listen to and I will as i just found out about you and you're critically underrated, hope you grow fast

[@GEOGIRL]

Aw, wow thank you! And thanks for the input, that gives me an idea to make a video about ice age animals/life in the future :D

[@Smilo-the-Sabertooth]

I’m very fascinated with the various forms of life on Earth, so imagining what Earth was like before there was life, it’s just a really interesting thing to think about. Thank you for another very fascinating video. Really interesting, really gives me a lot to think about. 😊❤😉👍

[@GEOGIRL]

Me too! I think you will like the part 2 to this one then ;) It is one of my favs! :D

[@Smilo-the-Sabertooth]

@@GEOGIRL I can’t wait to see it!!! You’re amazing my friend. ❤

[@barbaradurfee645]

Good Golly Girl! I can't keep up!!! Great job as usual.

[@GEOGIRL]

Thanks Barbara, you're too sweet ;)

[@ellenmcgowen]

A really excellent video, but there is a tension between "prebiotic Earth" and the most recent molecular dates for the genome of LUCA (the Last Universal Common Ancestor). LUCA's genome is reconstructed by phylogenetic methods from the genomes of bacteria and archaea near it on the Tree of Life; the reconstructed genome is that of a hydrothermal vent organism with a reverse Krebs cycle and nitrogen fixation. LUCA was a thermophile or a hyperthermophile. It had an Na+-dependent ATPase, and a fatty acid membrane that was leakier to ions than modern phospholipid membranes. It had no membrane proton pumps, but had an Na+/H+ antiporter. It lived embedded in the hydrothermal vent mineral matrix with hydrothermal vent fluid on one side and the ocean on the other. It reduced dissolved CO2 from the ocean using H from the hydrothermal vent. Now, LUCA was a DNA-world organism, and lived later than the first DNA organism, as well as later than the whole RNA-world. Yet molecular clock dates for its genome have been pushed steadily back through the Hadean, with the most recent estimates placing it at 4.5 Ga. That is a puzzle. It leaves essentially no time for all the abiogenesis, RNA-world, and early DNA-world evolution. Reconstructions of the protoribosome give us a window into RNA-world, and LUCA's genome as reconstructed has a full translation system and must have had a more developed ribosome than the protoribosome, which was just a heterodimer of tRNAs. It's almost enough to drive one to lithopanspermia :-) Thanks for all the great videos! BTW I take it you are familiar with the Hadean zircon data from the Jack Hills zircons. These results are reviewed in detail in T. Mark Harrison's book Hadean Earth (Springer 2020). Harrison discusses the conflict between these results (cool early Earth, early hydrosphere, early habitability, inclusions of possibly biogenic carbon grains in Hadean zircons) and the widely-held view that Late Heavy Bombardment suppressed life on Earth until 3.8 Ga. The planetary science community is aware that the Apollo lunar materials used to support LHB are probably from sites contaminated with Imbrium ejecta and give a falsely narrow range of dates. No samples from the lunar far side were returned by Apollo missions and these would be needed to support LHB, which is now considered uncertain. But in other fields such as biology the impression sometimes lingers that LHB would have repeatedly vaporized the oceans and suppressed all biology until the Paleoarchean; this is probably not true. Bombardment during the Hadean and Eoarchean would have been gradually decreasing and would have created magma basins, as it did on the moon, but never a global lava ocean nor a globally vaporized hydrosphere. Also, the Nice model which supplied an orbital resonance mechanism for LHB is no longer considered likely at such late periods after solar system formation: Jupiter and Saturn migrations are now thought to have happened very early, as in the Grand Tack model. Increasing knowledge of exoplanet systems has convinced astronomers that migrations are fast processes that occur early in planet formation. Many a young, forming exoplanet system already has a hot Jupiter that has migrated in from beyond the snow line.

[@GEOGIRL]

Wow! What an honor to have a person of your intellect in my comments right now! Thank you so much for all the information. I tend to lean toward the more widely accepted theories in my videos as to avoid controversy, but I agree that what we estimate for earliest life and LUCA varies widely depending on the reconstructions of that time period. I knew there had been estimates placing life all the way back to the 4's in terms of billion years ago, but I had no clue that it was as far back as 4.5 Ga. I am not very well versed on how long it would take abiogenesis to occur, but you don't think that less than 0.1 billion years would be enough? I feel like sometimes we place things at 4.5 Ga and that seems like it wouldn't be much time (from beginning of 4.5 to 4.4 Ga), but to me it still sounds like a very long time even on geological timescales... I don't know though, again I don't know how long abiogenesis would need. Also, I have heard of the LHB argument, but am no expert. It was my impression that the oceans becoming completely vaporized was not well backed up, and if life was present during this bombardment, it could've been protected at hydrothermal vents, but I don't know for sure, just what I've heard. Interesting to think about though! :D I hadn't heard of this planet migration model, but just looked it up, very cool! I never knew that, I wonder why they stopped migrating, and when this occurred, does that mean Earth and the other rocky planets are younger than 4.5? lol so many questions haha

[@ellenmcgowen]

@@GEOGIRL Thank you. One counter to the argument I presented is that abiogenesis might have been a fast process depending on wet/dry cycles which were more numerous on the early earth because of a faster rotation period. Maybe... But it was one thing to suppose that abiogenesis & RNA world could be squeezed into ~700 million years, and it's quite another to try to squeeze it all into ~100 million. There's a lot of molecular machinery in LUCA. Hydrothermal vents are one refuge life might have used during early bombardment; another is lithopanspermia from the Earth back onto the Earth. My own academic background was in math and astronomy, long ago, and later in life I studied biology out of a fascination with astrobiology. But I'm a complete novice in geo, and you definitely need some geo in this area. So I was delighted to discover your videos! Please keep up the great work for as long as you can; I'm sure there must be other academic demands on your time. Migration models that move Jupiter and Saturn back and forth across the solar system depend on impacts from matter in their "feeding zone"; migration is supposed to have stopped and reversed when Saturn cleared out the feeding zone behind Jupiter, so that Jupiter was receiving net outward momentum kicks from feeding on its sunward side. The terrestrial planets are all believed to have formed ~4.5 ga. If Jupiter and Saturn moved in and out it happened early enough to eat and scatter most of the early asteroid belt, but stopped short of devouring the Earth, and left only a terrestrial planet core as Mars. The entire migration, in and out, was probably over in 10s of millions of years. Thanks again!

[@GEOGIRL]

@@ellenmcgowen Thanks so much for the awesome information and the support! I greatly appreciate it and I am so glad you like my videos :) There are many other academic demands on my time, but making these videos is a fun hobby for me so it feels like a break. I love learning all these topics and can't wait to look into the topics & theories you've mentioned and hopefully someday make a video or two on them! Thanks again for the food for thought, and if you are ever interested, feel free to go into my astrobiology playlist and tell me what I have missed haha ;)

[@caspasesumo]

Great! I appreciate how you point out the importance of cycles in the geophysics and hydrology of Hadean Earth. Now you've got me all wound up for the first life video!

[@GEOGIRL]

Haha, well it'll be out next Wednesday, so hang in there one more week, but I really like both of these videos :) and I am glad you like this one as well! I just love all the geobiology content I get to talk about in this playlist, it's my fav!! :D

[@mi4208]

Great representation as always 👍👍👍👍 Glad to see that your subscriber have increased

[@GEOGIRL]

Thanks so much! I am glad too haha :D

[@JoesFirewoodVideosII]

This is my favorite content that you make and how I found your channel. Putting two videos out per week is a lot of work. I ❤️ GEO GIRL

[@GEOGIRL]

I love this type of content as well! I am so glad you like it ;) I hope to increase my earth history content a bit more after I finish covering the fundamental topics (like sedimentology & petrology) on my channel because I just really love telling the stories of earth's history, it's so interesting and we find out new things all the time! :D Yea, the two videos a week is hard to maintain, I filmed many of these over winter break and have been putting them out slowly, but I will run out soon and will have to go back to once a week for March and April. I am hoping to do twice a week for May though but we will see ;)

[@time_stone.7193]

Thank you 😊 for the best video on prebiotic evolutionary biology

[@RobCherwink]

FYI: in the "Earth History Playlist" this video appears as #8 _after the "Earliest Life" video (#7). Other than that it is a Great Job you are doing! I've watched more than a dozen of your videos now... Thanks! and Keep it up!

[@Beastclub679]

Very well done mam...🙂🙃🙃 Love from India..🇮🇳🇮🇳🙃🙂🙂

[@GEOGIRL]

Thanks so much!

[@Beastclub679]

@@GEOGIRL most welcome mam..😊😊

[@ChrisSmith-lk2vq]

Thanks for creating this amazing videos! I really enjoyed the content - please don't stop :-D Greetings!!

[@GEOGIRL]

Thanks so much! I am so glad you like my videos ;D

[@md.noorealamniash3298]

Very informative video. Enjoyed a lot. Thank you for the efforts. ❤

[@GEOGIRL]

Thanks so much! Glad you enjoyed it :D

[@davejackson9819]

Ooooooohh yes, I just started this one and i know it’s going to be a fav, 💕

[@GEOGIRL]

Hope you liked it! ;D

[@bessymathers7473]

I appreciate your channel and the effort you put into creating your videos so much! you made studying for my 'igneous petroloy' exams so much funner haha, so glad I found you! :΄)

[@GEOGIRL]

Aw, thank you so much for saying that! It is so nice to hear that you enjoyed the igneous petrology videos as well!

[@princeshukla7661]

THANK YOU SO MUCH AND Nice T-shirt WHO LOVE FROM INDIA

[@GEOGIRL]

It's WHOI with an I at the end, it stands for Woods Hole Oceanographic Institution ;)

[@kyakaethan1912]

you may want to make a video on external and internal earth processeses

[@GEOGIRL]

Thanks for the suggestion! I will work on it. Although there are so many earth processes, both internal and external, I may have to make a series of videos to cover that haha. ;)

[@kyakaethan1912]

@@GEOGIRL thank you very much cant wait;)

[@uncleanunicorn4571]

I never knew the oceans once had a ph of 1. That would explain how so many minerals could be dissolved to produce modern salinity compared with freshwater.

[@AmanSharma-un9cy]

Ma'am When are you making videos on Sedimentary petrology?

[@GEOGIRL]

I have a whole playlist on my channel about sedimentology & stratigraphy right now! Here's the link: kzbin.info/www/bejne/hmeuqKV9q8uIn9k There are only 4 lectures in that playlist so far, but I am putting out more every week! The next one comes out this Sunday! ;) Let me know if you have topic suggestions. I also have a sedimentary depositional environments playlist which you may find helpful: kzbin.info/www/bejne/eaDFm39mmr16ZpI

[@AmanSharma-un9cy]

@@GEOGIRL yeah I have a topic suggestion "Diagenesis" is it possible before 28th of February?

[@GEOGIRL]

@@AmanSharma-un9cy I have a few videos that cover diagenesis already, I will link them here: I talk about the physical process of diagenesis in this video, specifically starting around minute 16:00: kzbin.info/www/bejne/jZPZaqWIp7Zgldk But I also have videos discussing chemical diagenetic processes (mineral alteration & dissolution) like this one: kzbin.info/www/bejne/jGfRiICwjt2mi68 And last but not least, I talk about the changes made to porosity & permeability upon sedimentation and diagenesis in this video: kzbin.info/www/bejne/mJC8gJd_qrion5I and the chemical aspects of this (cementation processes) will be discussed in the next Sed Strat video coming out on Sunday Feb 20th. Hope these help! :)

[@AmanSharma-un9cy]

@@GEOGIRL thank you soo much...I wish you were my college professor 🙂

[@AmanSharma-un9cy]

Miss Rachael other than KZbin do you have any kind of online tutoring like live classes or something?? It's tough asking doubts or asking questions in the comment section😅

[@royaleblizzard2460]

can you explain where is the water comes from and Metals like iron, gold, etc.

[@GEOGIRL]

Sorry I should've mentioned, water, iron, gold, and all other substances that made up the planets, moons, and asteroids were abundant in the super nova that formed the solar system. More water vapor is present in the outer gas giants because the sun's heat caused a temperature gradient during the formation of the planets that pushed the volatiles (like water) further out in the solar system. But the water vapor that did remain in the inner solar system was associated with the rocky planets (like Earth). However, many planets, if they didn't develop a thick enough atmosphere or if they lost their initial atmosphere, lost their water content to space. Since Earth's atmosphere was thick enough to retain it's water content, an ocean was able to form as soon as Earth cooled down enough for the water vapor to condense. (I think initially, a lot of the water was also associated with hydrated minerals within earth's interior, however, this water vapor is released during volcanic eruptions, and is sourced to the atmosphere) As for the metals and other heavy, non-volatile material, these tended to accrete in the inner solar system forming the rocky planets (mercury, venus, earth, mars). But because of the way stars form and explode in super novae, the most abundant elements are always Fe and lighter on the periodic table because during a star's life, they can only fuse elements up to Fe then they get too heavy and die/explode in a super nova. The super nova is then what provides the energy needed to form the rest of the elements on the periodic table, but they remain less abundant than the others. Therefore, silica (SiO2) and silicate minerals containing relatively light cations (Na, K, Ca, Mg, Fe) are common in the rocky planets & moons, whereas heavy metals are present at lower concentrations which is why we often call them 'trace metals'. I have an old video about the formation of the solar system that may help: kzbin.info/www/bejne/sJSulHlrh7h2Zqc. Hope that helps ;)

[@royaleblizzard2460]

@@GEOGIRL I had differrent theory about the water and the Iron, both came from Meteorite and Comets, and it always outside of Solar System, but still the abundant of the water is still mysterious because only Planet earth has it. The evidence is not a direct to the earth due to earth is dynamic for billion of years, some theorist just suggesting as the Moon character it self that has plenty of Meteor Crater just after its created. Im not really sure and thats what Ive until now 🧐

[@GEOGIRL]

@@royaleblizzard2460 Really? I don't find the abundance of water on Earth that mysterious... I mean almost all bodies (planets, moons, & comets) have water (or ice), even Mars with such a thin atmosphere has a lot of water (it is just ice), and then there are fully ice covered moons which contain more water than earth (even liquid water). I am not sure what the second part of your comment means... yes, the moon has craters, but what is the question? Sorry if I misunderstood, hope this helps at least a little :)

[@royaleblizzard2460]

@@GEOGIRL it just one of Theory.....kind of, I think the Moon crater is the early moon form, that so many debris by the theory of mars size planet hit the young earth, what makes unique is the earth has too much water even surpases venus even after the collision that breaks almost a half of the young earth it self to outer space.

[@anirudhk5059]

Thank you it’s great but can you please add captions to the video

[@GEOGIRL]

Yep, it's funny that you ask that about this video specifically because all my videos on my channel have cc and subtitles, but this video is giving me trouble and keeps glitching when I try to go in and add them, so I've contacted youtube to help me sort it out. I will let you know when they are added! ;)

[@princeshukla7661]

This WHO in the igneous petrology video😁

[@GEOGIRL]

Wow you know my videos better than I do! hahaha, very nice catch ;)

[@RM-yw6xe]

I'm curious when left/right symmetry happened.

[@danwylie-sears1134]

Would the threshold for formation of the primordial oceans have been 100C? I would think that they would have formed as soon as the temperature fell below 374C (the critical point of water), with an atmosphere consisting almost entirely of steam applying the necessary 217 atmospheres of pressure -- if the volume of ocean water then was anywhere near what it is now. -- Would the early atmosphere have needed O3 to absorb UV, or could other gases have done it? In particular, when the temperature was above 374C and the liquid water hadn't been separated from the gas, would water have absorbed UV, even at frequencies with low specific absorbance, just by the sheer quantity of it? It's like how the ocean is completely dark except for a relatively thin layer at the top, even though water is mostly transparent, because even a relatively thin layer of the ocean is absolutely thick enough to absorb all the light. -- This is not unreasonably long. I listen to lots of videos that are over 40 minutes long.

[@michaeleisenberg7867]

Rachel, I don't understand where all the water came from. Earth started out as a ball of molten hot magma so where was the water sequestered? Could enough comets have smacked into earth and delivered all our water? That sounds too simple. Keep these coming, please. Thank you! Best Wishes, Dr. Mike

[@trilochankumar8533]

Mam what is source or water in primordial earth,,

[@GEOGIRL]

Condensation of water vapor :)

[@GEOGIRL]

@Daniel Anuchan haha no! Sorry I should've mentioned, water vapor was abundant in the super nova that formed the solar system and it condensed in association with other accreting material to form the planets. More water vapor is present in the outer gas giants because the sun's heat caused a temperature gradient during the formation of the planets that pushed the volatiles (like water) further out in the solar system. But the water vapor that did remain in the inner solar system was associated with the terrestrial planets (like Earth). However, many planets, if they didn't develop a thick enough atmosphere or if they lost their initial atmosphere, lost their water content to space. Since Earth's atmosphere was thick enough to retain it's water content, an ocean was able to form as soon as Earth cooled down enough for the water vapor to condense. (I think initially, a lot of the water was also associated with hydrated minerals within earth's interior, however, this water vapor is released during volcanic eruptions, and is sourced to the atmosphere) Sorry, I am no astrophysicist so I may be missing key details or slightly off on some, but this is how I understand it. Hope that helps ;)

[@billkallas1762]

What was the temperature of the Earth during the Heavy Bombardment? Didn't we gain much of our water then??

[@nyoodmono4681]

Earth has many dresses. When the oceans where flat and oygen was scares it was green, when the iron oxidated it was red, when snowball earth hit it was white, now it is blue and during the great bombardment it was still black, maybe :-)

[@MrGuzmanra]

And the water? where did it come from and why did not boil off? is water too heavy to escape the earth?

[@GEOGIRL]

Water vapor was abundant in the super nova that formed the solar system and it condensed in association with other accreting material to form the planets. More water vapor is present in the outer gas giants because the sun's heat caused a temperature gradient during the formation of the planets that pushed the volatiles (like water) further out in the solar system. But the water vapor that did remain in the inner solar system was associated with the terrestrial planets (like Earth). However, many planets, if they didn't develop a thick enough atmosphere or if they lost their initial atmosphere, lost their water content to space. Since Earth's atmosphere was thick enough to retain it's water content, an ocean was able to form as soon as Earth cooled down enough for the water vapor to condense. (I think initially, a lot of the water was also associated with hydrated minerals within earth's interior, however, this water vapor is released during volcanic eruptions, and is sourced to the atmosphere). So yes, in essence, water was too heavy to be completely lost from Earth's atmosphere, in contrast to gases like H or He which were readily lost to space despite the presence of the atmosphere. BUT I am no astrophysicist so I may be missing key details or slightly off on some, but this is how I understand it. Hope that helps ;)

[@MrGuzmanra]

@@GEOGIRL too bad Mars lost its 💧 water. We might have two planets with life in the solar system 😀.

[@GEOGIRL]

@@MrGuzmanra Well, mars actually still has a lot of water, but it's mostly frozen or underground. But I agree, I think there'd be a much better chance for life on Mar if it had liquid water oceans at its surface ;)

[@erictaylor5462]

10:30 It's odd to think of lightning fixing anything. Usually it just breaks things kzbin.info/www/bejne/f2WbY6dsf81_ask

[@leechild4655]

There must have been a cloud earth (late Hadrian?) where so much rain and lightening covering vast areas all that gas converted to liquid became the new crust on the planet. a mostly water planet. The oceans are from the condensation of that cloud earth 3-4 billion years ago? its a theory. ;-)

[@favourites4]

Geo Girl I want to live in your Geo-world....

[@GEOGIRL]

I am more than happy to have you join me in my Geo world ;)

[@KerriEverlasting]

Omg lightning?!? Wow! That's so interesting. Omg.

[@davidbrisbane7206]

Physics Girl vs Geo Girl. Mud wrestling. Now!

[@GEOGIRL]

hahaha this comment is everthing🤣

[@davidbrisbane7206]

@@GEOGIRL I think you'd win 💕💕💕

[@TarkMcCoy]

It smelled really bad, and the clubs were dead...

[@GEOGIRL]

Hahaha, sounds awful when you put it that way🤣