Creationists can't comprehend that related animals have a suite of shared morphological characterists that link them together into nested hiearchies. They think animals are hobbled together from a set of fixed things like lego heads, bodies and limbs. This is why they ask 'where is the half wing?' or 'where is the croc-a-duck?'
These videos are excellent! I am wondering- What methods do paleontologists and geologists use to determine whether what they are examining was on dry land and not under water? You do a great job of presenting the evidence, mentioning some spores and burrows as evidence that strongly suggests plants were on land at that point, but what is it about this evidence that suggests it is related to dry land? You mention that all of the seedless plants mentioned from the late Devonian with related extant organisms that exist today are aquatic, and the seeded ones can't survive away from water. What is supporting the assumption that any of this was on dry land at the time? Thank you!
It's not always clear. Some of it is based on fossils themselves, e.g., the presence of casts of roots vs. lots of shelly material, some is based on structures within sediments (raindrops, mud cracks, channels, etc.), some is based on associations of between layers of rock that allow overall environmental context to be determined (e.g., mudstones with laterally truncated sandstones representing rivers and floodplains).
Just wondering why Prototaxites needed to be so tall, and how it held up in the wind? Modern above ground/substrate fungi are usually just the fruit bodies, or the travelling 'bootlaces' of Honey Fungus types. There is only a need for them to be tall enough to get into the moving airflow above the soil or nearby plants. Modern cylindrical 'earth toungue' types of similar shape to Prototaxites, are rarely as much as 6" tall. So why did Prototaxites get so tall, that it was near the limit for a column of water held up by a vacuum against atmospheric pressure? What was it for? Not a fruit body? So what? Could it be that: this is the way mycorhizzal symbiosis used to work before soils were well developed and plants were short and had rudimentary or no leaves? What if the point of these gas and water filled collumns, was to be the gas exchange organs of the symbiosis? The gas exchange organ would be as tall as possible, and only wide enough to fulfil its support function, while maximising the surface for gas exchange with the hyphal network inside. The organ is not utilising the CO2 itself, as the isotope ratio shows, but it could transfer oxygen to the decomposing hyphal network below ground, and through this, it could exchnge fresh CO2 with the plants around, without the need for leaves. It might be that the axial capilliary system is aided both by atmospheric pressure and evaporation/wicking, so that water is drawn up from below, recharged with gases and sugars for fungal maintainance, and interconnected hyphae pump the freshly aerated water back down to the plants as the whole collumn is buffetted by the wind? Once proper trees began to spread, this mechanism would not be needed any more, as the advanced vascular system makes the fungal gas exchange collumns unnecessary. (Wonder if there are genes that could be turned on to make these spectacular organs once more!?) Still not sure how such tall things didn't blow down, but many fibrous fungal stipes are very tough and flexible, so, maybe they did just whip about in the wind, and it's just the illustrations that make it look odd.
These lectures cover a different territory (or the same from a different viewpoint) than the purely paleontologic ones, which make them enlightening and fully complimentary. Can the corresponding pdf's be accessed? I am watching this in a trance! MORE PLEASE!!
Your comment motivated me to actually give them titles and create a playlist, so thanks! (They were originally embedded in my course page, so I never bothered doing that at the time). Enjoy!
Just trying to identify some fossils from between cataract formation and Burnt Bluff in Michigan basin. They look like black crowberry fossils. In a blue shale above gypsum pocket.
Your average person would be very surprised to learn that during this geological period there was no grass and that grass didn't appear till 30-40 million years ago.
I don't remember whether I said this, but grass did exist, based on the presence of grass-specific bits of silica in dinosaur poop. But, grasslands as a biotope didn't evolve until millions of years later. www.indefenseofplants.com/blog/2019/9/27/history-of-grass-evolution-written-in-dinosaur-poop
This is a good example of convergent evolution. The scales of fish and reptiles have completely different structure and grow in completely different ways. They aren't actually the same thing.
Please use 'alga' when the singular is appropriate, not the plural 'algae', same for bacterium and bacteria. You owe it to your students to use the proper forms. Really, there is nothing good about promoting ignorance about proper singular and plural formations about words used in scientific jargon. You may not like the dependence on ancient languages - I'm not too keen on it - but it does provide information and makes it sound more like you know what you are talking about.
@@jasonloxton2785 Their content is informative, I just find their presentation patronising and annoying with that forced goofiness. By coincidence I saw Anton Petrov's video this morning about a paper suggesting sponges may have been much earlier than previously thought. It will be interesting to see how that research develops.
The older I get the more the history of life on earth fascinates me. I find your lectures to be most stimulating. Thanks.
I love learning while washing the dishes.
I've enjoyed all of these lectures and I've learned a lot.
This is purely gold. Thanks for putting this series together. I currently live in China and will visit Chengjiang fossil group soon.
Creationists can't comprehend that related animals have a suite of shared morphological characterists that link them together into nested hiearchies. They think animals are hobbled together from a set of fixed things like lego heads, bodies and limbs. This is why they ask 'where is the half wing?' or 'where is the croc-a-duck?'
These videos are excellent! I am wondering- What methods do paleontologists and geologists use to determine whether what they are examining was on dry land and not under water? You do a great job of presenting the evidence, mentioning some spores and burrows as evidence that strongly suggests plants were on land at that point, but what is it about this evidence that suggests it is related to dry land? You mention that all of the seedless plants mentioned from the late Devonian with related extant organisms that exist today are aquatic, and the seeded ones can't survive away from water. What is supporting the assumption that any of this was on dry land at the time? Thank you!
It's not always clear. Some of it is based on fossils themselves, e.g., the presence of casts of roots vs. lots of shelly material, some is based on structures within sediments (raindrops, mud cracks, channels, etc.), some is based on associations of between layers of rock that allow overall environmental context to be determined (e.g., mudstones with laterally truncated sandstones representing rivers and floodplains).
Thanks a lote
Amazing
GIve us more lectures please. Very enjoyable and educative. Thanks for uploading from Germany!
Is a subscription free?
Yup. Not that I put up a ton of stuff, but what I do is free. :)
Just wondering why Prototaxites needed to be so tall, and how it held up in the wind?
Modern above ground/substrate fungi are usually just the fruit bodies, or the travelling 'bootlaces' of Honey Fungus types. There is only a need for them to be tall enough to get into the moving airflow above the soil or nearby plants. Modern cylindrical 'earth toungue' types of similar shape to Prototaxites, are rarely as much as 6" tall. So why did Prototaxites get so tall, that it was near the limit for a column of water held up by a vacuum against atmospheric pressure? What was it for? Not a fruit body? So what?
Could it be that: this is the way mycorhizzal symbiosis used to work before soils were well developed and plants were short and had rudimentary or no leaves? What if the point of these gas and water filled collumns, was to be the gas exchange organs of the symbiosis? The gas exchange organ would be as tall as possible, and only wide enough to fulfil its support function, while maximising the surface for gas exchange with the hyphal network inside. The organ is not utilising the CO2 itself, as the isotope ratio shows, but it could transfer oxygen to the decomposing hyphal network below ground, and through this, it could exchnge fresh CO2 with the plants around, without the need for leaves. It might be that the axial capilliary system is aided both by atmospheric pressure and evaporation/wicking, so that water is drawn up from below, recharged with gases and sugars for fungal maintainance, and interconnected hyphae pump the freshly aerated water back down to the plants as the whole collumn is buffetted by the wind?
Once proper trees began to spread, this mechanism would not be needed any more, as the advanced vascular system makes the fungal gas exchange collumns unnecessary. (Wonder if there are genes that could be turned on to make these spectacular organs once more!?)
Still not sure how such tall things didn't blow down, but many fibrous fungal stipes are very tough and flexible, so, maybe they did just whip about in the wind, and it's just the illustrations that make it look odd.
Honestly, no idea. But now you've got me curious!
Why would a decomposer fungus grow to 8 meters tall, what advantage would it grant?
These lectures cover a different territory (or the same from a different viewpoint) than the purely paleontologic ones, which make them enlightening and fully complimentary. Can the corresponding pdf's be accessed? I am watching this in a trance! MORE PLEASE!!
great lecture where do I find the following lecture you mentioned
Your comment motivated me to actually give them titles and create a playlist, so thanks! (They were originally embedded in my course page, so I never bothered doing that at the time). Enjoy!
@@jasonloxton2785 Have you published any books?
@@nicholasmaude6906 Not yet. Just my PhD thesis, but trust me you don't want to read that! :)
@@jasonloxton2785 Will you write a book? Because I'd definitely read it you published it:).
I can't fathom what forces of natural selection made prototaxites grow so tall.
Just trying to identify some fossils from between cataract formation and Burnt Bluff in Michigan basin. They look like black crowberry fossils. In a blue shale above gypsum pocket.
Your average person would be very surprised to learn that during this geological period there was no grass and that grass didn't appear till 30-40 million years ago.
I don't remember whether I said this, but grass did exist, based on the presence of grass-specific bits of silica in dinosaur poop. But, grasslands as a biotope didn't evolve until millions of years later. www.indefenseofplants.com/blog/2019/9/27/history-of-grass-evolution-written-in-dinosaur-poop
How do the fish have scales, then the amphibians don't, an d then reptiles do again.
This is a good example of convergent evolution. The scales of fish and reptiles have completely different structure and grow in completely different ways. They aren't actually the same thing.
@@jasonloxton2785 Wouldn't it make more sense if modern amphibians just lost them after they diverged from reptiles?
@@ImagesOfAustin Reptile and fish scales are made of completely different materials (keratin vs. enamel and dentine).
Wait so harvestmen are an ancient species? Neat.
Nightmare fuel from eons past
38:20 the Chonky Boy theory of land colonisation.
Please use 'alga' when the singular is appropriate, not the plural 'algae', same for bacterium and bacteria. You owe it to your students to use the proper forms. Really, there is nothing good about promoting ignorance about proper singular and plural formations about words used in scientific jargon. You may not like the dependence on ancient languages - I'm not too keen on it - but it does provide information and makes it sound more like you know what you are talking about.
These were done off the cuff without editing. You try talking for an hour and half in the middle of pandemic and not making a few errors.
I can't stand PBS Eon's sophomoric style. Had to skip past that bit. The rest of this lecture series has been wonderful so far, though.
Fair enough. I really love Eons. Even with a PhD, I almost always learn things, but each to there own. Taste is subjective!
@@jasonloxton2785 Their content is informative, I just find their presentation patronising and annoying with that forced goofiness. By coincidence I saw Anton Petrov's video this morning about a paper suggesting sponges may have been much earlier than previously thought. It will be interesting to see how that research develops.
@@WaterShowsProd prob. because most ppl like the style. Find it irritating too tbh. Subjective overall.
@@feralphil1198 Agreed, to each their own.
Viewers are not stupid. You need to stop drawing so much on your images as if they were toddlers.