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Current time:0:00Total duration:5:35

Video transcript

in the video on the Cambrian explosion I talked about how surprisingly or somewhat surprisingly that animals were the first to colonize or to move on land they were but they did that before plants did and someone brought up what I thought was a very good question if the animals were the first what did they eat so I thought that that just that was one a good question so it just divided a whole a whole video on clarifying exactly who was first on the land so right here this is a picture of algae on the coast this is kind of algal scum right over here so this right here is algae and just to be clear sometimes cyanobacteria which we talked about is the first photosynthetic organism sometimes that's called called blue-green algae but that's really bacteria algae is considered to be eukaryotic and it just doesn't have the structures of modern plants so this is algae right here and our best our best estimate is that algae actually colonize kind of coastal rocks about 1.2 billion years ago so this is 1.2 billion years ago G for a Giga billion years ago so if you wanted the first thing that even resembled or was close to plants or animals and if you consider algae close to a plant then this would be the winner of who got on land first this is 1.2 billion years ago now in the last video where I talked about animals colonizing the land first they weren't animals that only existed on land they were they would have been animals that probably spent most of their time in the ocean collecting food or whatever and then they would show up on the land maybe delay eggs and if you think about it back then the land would have been a really good place to lay eggs because there was there wouldn't have been much else on the land so you'd have been protected from pettite predators so it might have been it might have been slug-like creatures like this some people talk about kind of spider like creatures but it still would have been at the coast and these would have been these would have been creatures that would have spent a lot of time in the ocean and sometime in their land so this is what I was referring to as kind of animals colonizing the land before plants and this would have happened about five hundred and thirty million years go five hundred thirty five hundred thirty million million years ago now the first the first living organisms to fully live on the land their whole life is on the land those would be plant so it depends what if you think about things that live part of their life you get the animals things that live the whole life on the land then you go back to the plants so this right here this is what we think the first primitive plants would have looked like and the evidence we actually don't have fossils from these plants themselves we have fossils of their spores but we think that these the earliest fossils of their spores will show that these existed were about 475 million years ago so this is 400 metres in another color this right over here is 475 million years ago so 1.2 billion years ago you have the algae 530 million years ago we have evidence of things kind of oozing out of the ocean and maybe laying their eggs or something 475 million years ago we have evidence of what we would kind of call really plants but the evidence is really the the fossils of their spores and then the first evidence of real I guess you could call them animals that are spent their entire life on the land the oldest fossil we have it was discovered in Scotland fairly recently in 2004 and it was this is the fossil right over here was actually discovered by a bus driver by Mike Newman Mike Newman who was a bus driver in Scotland and they actually named the thing after him it's called new mo desmos Nnamani so they got the the new money from Mike Newman and this fossil is 428 million years old 428 million million years old and right now it's the oldest fossil we have of a true land animal so if you think about true land if you think about true plants versus true land animals things that spent their entire life on the land the plants do win out if you think about things that spend part of their time on the land then the animals probably won out if you think if you view algae as plants and the plants won out so it depends where you want to draw the line and this this first fossil this is this is of a myriapod which is which just means a lot of legs let me write over here myriapod you probably know the word myriad myriad means a bunch of things are you know a huge amount so myriapod a huge amount of a huge amount of legs and you might be familiar with the millipedes and centipedes those are myriapods and so those first primitive myriapods 428 million years ago and they would have lived off of plants and maybe other myriapods and other slugs and whatever other animals they might have found might have looked might have looked something like that so hopefully that gives a little bit of clarification over I'm it wasn't like you know you had a dogs sitting on the land and they had nothing to eat it was kind of a you know it's it's not it's kind of a gray or and what you define a plant or an animal and who gets kind of the bragging rights for being the first on the land and it depends on really what you consider a plant or animal and whether you know spending part of your life on the land whether part of spending part of your life on the plant on the land will actually qualify
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