Journey to the Microcosmos, I want to thank you for you have been part of my precious niece's decision to change courses from nursing to medical technology which will cover the fundamentals of microbiology. I bought her a cool microscope which I think will be a nice investment after finishing her degree. Now, she is teaching my young son fascinating things about microbes. I love seeing them enthused as they peek into the microscope. Anyway, as always, thanks for another enjoyable and edifying upload. This episode on choanoflagellates is most enlightening.
"they spend most of their life not moving around" "stick themselves to a sturdy surface and grab whatever food passes by" so they really are our ancestors huh
To be fair, they are still alive and kicking it. Since they still make history I reject the prefix "pre". They are just historic?! Anyway, you got mad skills if you can draw these!
I appreciate the writing of this series. It is clear enough for someone without a science background to understand, but still informative and precise enough to be enjoyed by people with microbiology backgrounds. Like me! (Now I just gotta to use my degree for something.....)
If you had microscopes like this at your school, you would have already had to be rich... and be at a school that made cgi videos of what microbes might look like
I do Microscopy in my daily work with Children and you guys and girls helped me so much in understanding more of the Microcosmos and its variety in microbes etc. The work you upload here for free is amazing and let me tell you one thing. Your impact is bigger then you might expect, the kids love our Microscopy Projects and im glad I learned a lot of Knowledge from your Content that I can teach the children. Keep it up! :)
Hi MicroCosmos, Great channel name. I am OBSESSED by the idea that life can travel from planets to planets through meteorites. Kinda reminds me that. Awesome content, keep posting ! New fan
I clicked on this video both to watch it and learn more about the micro cosmos and to see how any creationists had a meltdown in the comments. I was not disappointed on either front
That's a complicated topic. It was a process called abiogenesis, and I'll be real with you, while we have the starting points of an understanding of the process, we still have absolutely no idea how it happened. What we do know is: - The early Earth's oceans were a mixing pot of organic chemicals (those are chemicals with a carbon skeleton/structure) and all kinda of chemical reactions. These chemicals arrived on Earth from the building blocks of the planet, i.e., asteroids and comets, and we still find them in abundance in asteroids and comets to this day. - Somehow this 'primordial soup' generated the first living cells. It is likely that phospholipids (the chemicals that make up cell membranes) could've formed 'bubbles' of isolated chemistry. Any RNA that spontaneously generated in the primordial soup could've been captured in these bubbles, and provided conditions were acceptable, could've self-replicated to produce more RNA. In doing so, it would have acted like a single-molecule-sized living thing, eating (RNA nucleotides), reproducing (self-replicating), and evolving (random mutations). As with all things evolution, most mutations would suck. However, any beneficial mutations in the RNA structure would allow the RNA molecule to replicate more efficiently. In doing so it might out-compete other RNA sequences trying to do the same thing, becoming dominant in its environment. This process would continue until RNA gained the capacity to catalyze the formation of more complex structures, such as polypeptides (proteins), forming the first, true cells. This would've created an early Earth that was dominated by RNA-based life: the theory is called the "RNA world hypothesis". (FYI, RNA that catalyses things is called a ribozyme, and is the RNA equivalent to an enzyme. Ribosomes do this in cells to this day). - Somewhere along the line, RNA somehow got switched to DNA, providing us with our DNA-based world we see today. - Problems with this whole concept: somehow, cells must've gained the capacity to take in energy from their surroundings in order to facilitate their own chemical reactions. E.g., photosynthesis, but more likely, chemosynthesis. How this could've possible occurred is totally unknown. It's thought a likely place for it to have occurred, though, would be deep sea hydrothermal vents. Some scientists think having a metabolism is so important that this must've occurred first, before the addition of self-replicating molecules (metabolism-first hypothesis), but others remain convinced that self-replicating RNA was the initial kick that got abiogenesis going, and later, from this, RNA-based metabolisms arrived (replicator-first hypothesis). - Another problem: we have no idea how RNA could self-replicate on its own in an early-Earth environment. It requires changes in environmental energy to do so, and we really haven't got any good understanding of this process yet... If you hear about something called "panspermia", this is another idea for how unicellular life arrived on Earth. Basically, the theory goes: life arrived on Earth riding comets or meteorites, from somewhere else in the universe. While totally possible, this alien life would still have to have gone through abiogenesis somewhere else in the universe, so it just pushes the problem of the origin of life further back rather than explaining it. So, ignore anything about panspermia if you're trying to learn about abiogenesis.
@@SynKronik Viruses aren't entirely what you'd call 'living' and we're not sure if any of their ancestors were either. They could be the result of cells losing elements and becoming parasitic, or they could've evolved inside cells from bits of DNA that are able to move and copy themselves like plasmids or transposons. We don't actually know.
@@dylaneverett4586 __ Given that the Earth seems to be a life-hosting planet, rather than a life-producing planet; the simpler and more likely explanation is that the genetic codes of life got transported to Earth via life-seeding aliens intending to disperse life throughout the universe. By all means outline why you do not prefer that as the more logical and likely explanation, but keep in mind that within a thousand years humanity itself will become life-seeding aliens when the genetic codes of life get sent one-way to candidate life-supporting planets in order to disperse life throughout the universe.
@@SpongeBobImagination Ok, as scientists we don't rule out possibilities like this until proven otherwise. This, as you have stated, could hypothetically be possible. That being said, it's unlikely for a few reasons, and it's definitely not "the simplest explanation" as you put it. - We haven't seen evidence of extraterrestrials, ever, no matter how far or thoroughly we search. We've barely even discovered bio-signatures of life outside of Earth, and even these are controversial. To explain your idea, you'd have to first explain the existence of extraterrestrials, how and why they would spread life across the universe (if by accident or purposefully, and why), where they themselves came from, why they haven't shown up since, how they traveled from other star systems (you'd need to explain FTL travel, or if not, why they'd bother to come here in generation ships), etc. etc. etc. - Those extraterrestrials would, themselves, have had to have gone through abiogenesis at some point. Thus, abiogenesis would still have had to occurred regardless, making this argument akin to the panspermia hypothesis - invalid when considering the true origins of life in the universe. It just pushes the origins of life further back in time rather than helping to explain the process. Again, this makes the hypothesis less parsimonious than the abiogenesis hypothesis. - LUCA, the last universal common ancestor of all life on Earth, based on DNA analysis, was most likely a hydrothermal vent endemic autotrophic microorganism (doi.org/10.1038/nmicrobiol.2016.116). It was very simple and supports the hypothesis of abiogenesis/evolutionary divergence. - The argument that the Earth is "life hosting" rather than "life-producing" is invalid for numerous reasons. One, the Earth as we see it today is hardly comparable to the toxic, boiling mixing pot of chemicals and protoplanetary material that the Earth was when life first emerged on it. Two, if a series of chemical reactions began to occur in which life might arise again, the life that already thrives on our planet would out-compete, and if not, probably consume these simple RNA compounds. Many bacteria do this today through osmotrophy. The planet, through the appearance of life, has simply become incapable of going through abiogenesis a second time. There's many other reasons this is invalid... I could go on. Of course, the idea of life being transmitted by aliens isn't impossible. That being said, it's not parsimonious. In science, nothing is aliens... Until it's aliens. If other hypotheses exist, they're more parsimonious from our current understanding of the universe. If I were you I'd remain open to other possibilities. It's always good to speculate, but you should never be so sure of your ideas until they're tested and either proven or falsified - and your idea is not falsifiable, so it can't be tested, and therefore it's not of use to us as scientists. We don't currently know how life first appeared on Earth. It's better to be open to all the possibilities rather than to assume one is true, even if it sounds cooler than the others. Plus, trust experts on the topic. If they don't consider it a valid hypothesis, let's trust them on that assumption.
No, they definitely would've had to change because the planet and other living things around them have also changed. When people talk about 'living fossils' they mean that the outward or general appearance and food finding strategies of a creature are more or less the same as they were a very long time ago, not that they're entirely the same. Some body plans and strategies simply work well enough that there's no need to make big changes
@@limiv5272 Agreed, I mean it seems like they messed up with semantics a bit. I hate when creationists abuse these small mistakes to argue against evolution theorum.
2:36 oh my god stop calling them "ancestors". they are not our ancestors, they SHARE an ancestor WITH us. and people wonder why there is so much misunderstanding of evolution when science educators talk about it like this.
@@aarusty51 yes, because it has evolved to react that way. This behaviour lets it surive. Because it survives it exists, if it doesn't survive, it is the end of it. The life you see is the one that has managed to survive to this point. Everything that hasn't survived is gone.
@@aarusty51 No, you are the one who needs to do some deep thinking on the subject. It's not that hard to comprehend. Think harder, perhaps you'll get there.
evolution sure puts a wrench into human belief systems. confucian ancestor worship means you shouldn't wipe off the moss off your shoes. maybe you should even pray to it.
@@nightbling8905 well... science doesn’t have to say anything about any god, it’s not something you can either prove or disprove using scientific methodology. To be fair, you can accept evolution and believe in a creator.
Sorry? that is my great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great great.... ... grandfather, we use proper naming here
