This is as good as it gets in the realm of biology documentaries. Everything we knew about giant insects 60 yrs ago, plus all the subsequent related discoveries and theories. The animations, maps and use of scientific names are of universal appeal. We even meet the scientists themselves. 5 stars out of 5 ! And many thanks.
Thank you! We are glad that you enjoyed this video, this documentary is part of series from which we also published the second episode right here : th-cam.com/video/EC816OQPnjI/w-d-xo.html 😉
@@ummeli2 I will venture an answer. Some level of carbon dioxide in the bloodstream causes us to breathe. Breathing high oxygen level causes hyperventilation decreasing that trigger and stops breathing to fainting or unconsciousness. BUT man being man, will have culture on its side. Technology. Breathing masks. Lol.
@@ummeli2 Because our bodies were not designed for it. It's weird to me too, like, we breath oxygen and it's a good thing right? But that's not the case, it's just something we know from grade school where you are taught "oxygen is good". Remember oxygen is just like any other element, and we have adapted to the lower oxygen levels of today. Back then, there were no mammals that could survive the high oxygen, and therefore the species that COULD grew to be massive. Adaptation is a strange thing my friend.
The most straightforward reason these (HUGE) insects ('simply') disappeared is for the same reason they APPEARED: the oxygen level of the planet's atmosphere. Since insects breathe through spiracles (tiny little openings in their bodies through which muscular contraction sucks air in and pushes it out, allowing them to inhale and exhale), the higher the oxygen level, the more capable they are of sustaining a large body. However, in an atmosphere such as ours today, it's impossible for the air to get into a 10-foot-long centipede and enable it to 'breathe'. Simply put, less oxygen in the atmosphere means smaller insect bodies and higher oxygen means larger insect bodies. There is ONE other vital thing to bear in mind: insects have exoskeletons, and as they get bigger, they need more oxygen, but at a certain point, the weight from carrying the support structure on the outside becomes too unbearable. In other words, there's the topmost limit an insect's body plan can reach-even in a highly oxygenated atmosphere. If I remember correctly, an experiment was done in which larval insects were 'raised' within a sealed, highly oxygenated structure and grew more significantly than usual. These insects couldn't survive outside of this very restricted environment...they were sort of the "insects in the plastic oxygen bubble" (if anybody gets that reference, give yourself a ⭐️😉).
Actually, there isn’t a consensus on this. Other studies show the oxygen level wasn’t that different from what it is today and may have even been lower. Stating this as a fact is misleading people.
What about the blue whale? Not alot of air under water, they do come up for air but what about that respiratory system VRS weight VRS energy requirements equals a massive need for air... Yet it defy evolution
@@ElectronFieldPulse no , for many millions of years before the Cambrian explosion ( which is when these super bugs arrived) the earth was covered in algaes , mosses and other primitive flora all photosynthesising. Inhaling co2 and exhaling oxygen. 13:16
what we have failed to address is there nymph stage? How much oxygen was in the water? The size of nymph will determine the size of the adult . These insects don’t live very long once they’ve reached this phase in their lifecycle. I don’t believe they grow any more. Perhaps the size was relevant to more of the aquatic environment and food source.
A comment about the large insects of the Permian period. The hypothesis is that the action of flight also caused compression of the thorax, which pumped oxygen to other parts of the body. I can see a possibility in that for the adult dragonfly. But in it's nymph stage it would not have wings and therefore no pumping mehanism. The nymphs would most likely have had to have been of a similar body size to the adults. So the mystery is not completely solved. An interesting aside is that due to the insects having an exoskeleton, there were also limits to their size. Their internal organs had to be attached to the outer exoskeleton. This also meant that they could not withstand sudden movements, or abrupt stops well.
Good Science ASMR for sleeping thanks. You pass the requirements - relaxing voice and music, interesting content, and over 30 minutes long. Subscribed :)
It is though. Things you think of as "flammable" are the rule not the exception in our Universe. Most of the Universe is Hydrogen. The majority of the planet mass in our solar system is "flammable", H2, CH4, NH3... There is at least one major moon with lakes, seas, and icebergs made entirely of hydrocarbons. There is even violent lightning. But there is no fire out there. Only here on Earth. Because only here is found O2.
I LOVE these films! I remember the disappointment of so many adults that stuff like this was not available on the new miracle of TV. Think how smart we'd all be if quality learning shows had dominated TV shows like this?
But it was HOT and humid. Thus there were lots of large fern trees, etc. at the time. Wouldn’t have been pleasant living then. And the air was “extremely flammable”. So, maybe not a good atmosphere.
Life needs hundreds of thousands, sometimes millions of years to adapt to radically different climates. Also an enormous portion of Pangea was extreme desert. Depends on when in the Permian, but hot, arid desert would have extended up to about 30º latitude, north and south. If we did that again, almost all of Africa, all of India, and the most heavily occupied parts of China would all be hot, arid desert. If you're implying it'd be fine to return to those temperatures, a lot of people will die from drought, famine, or heat stroke, and many billions (with a b) would be displaced.
Insects do not breathe into lungs. They have tiny holes along the sides of their body is called spiritual and so the oxygen concentration is a big thing.
If the iron was oxidised in the red sediments, there must have been more oxygen in the environment than in the intervening middle Permian period. Why does that not explain the increasing size of the insects? The question should be why was there more oxygen at this period?
@@ElectronFieldPulse- Red sediments should mean more oxidised iron compared to other times, so more oxygen. I am curious about the alternative explanation.
@@geoffreyM2TW - I just deleted my comment, I did not remember the paper correctly. The Carboniferous period had peaks and troughs, and in some of the troughs it did dip to today’s levels, but it also had elevated levels which reached the 35%. So, my statement about the whole period being that way was misleading. The thinking is that some of these insects seemed to have overlapped with some of the troughs so they are unsure about the relationship with insect size and oxygen level. It wasn’t quite as overarching as I initially claimed.
@1:30 "Oxygen makes the air extremely flammable." And what is the fuel, nitrogen ?! That has to be the stupidest . . now I can't believe anything you say, Goldberg.
7:34 While the models tjemselves look a bit plastic, the feeding behavior and interactiom between the two animals is very well animated. It looks like they studies real insect behavior to nail down the movements and feeding procedure.
It has to do with the partial pressure of the atmospheric oxygen at that time (Boyle's Law). If the pressure and/or concentration of oxygen exceeds the equivalent of 23% at 1 Atmosphere (sea level on current day Earth) then human physiology and biochemistry starts to be affected. Prolonged exposure to conditions not optimal to humans leads to death.
@CharlesCurran-m9p People in hospitals breath 100% oxygen. Originally, the 1960s astronauts were going to go into space at 100% oxygen until a spark started a fire. Higher oxygen levels like what existed during the dinosaurs would be perfect for us.
@ I don’t believe patients in hospitals use pure O2 for extended periods but for COPD patients for example, sometimes do and that’s where the problems occur. That’s why they usually use 40% O2.
Допустим. Если ученые настолько уверены в своей теории почему не посадить мух дрозофил в герметичную камеру, создать там повышенную концентрацию кислорода и получить муху размером с кошку? 😂
Not many people know that the earth had a super continent in the carboniferous period and all the coal on earth was all laid down in one go all at the same time in the northern hemisphere. Also due to the increased oxogen content fires burnt much longer, further and hotter than in today’s climate and things broke down a lot faster as the oxogen caused oxidisation which meant organic matter broke down much quicker than in todays climate but unlike todays atmospheric oxogen content compared to back then it allowed insects and invertebrates to grow to super sized proportions.
The reason why there was so much oxygen was because the amount of plant grow was magnitudes greater than today because of the higher co2, about 10 times higher than today.
Damn! I don't feel bad for humans that are experimented on by Aliens anymore. I can hear that cricket now telling his friends and family how he was abducted and probed!
Umm actually humans can live in that high of oxygen, people just don't have to breathe as much. There are these things called red blood cells, your body produces less or more depending on its needs.
Whoops, high humidity lowers air density not increases it. US helicopters had lower lifting ability in Vietnam with its high temperatures and high humidity.
The idiotic comments here are proof of two things. Most don’t bother to actually read much, and don’t read primary sources at all ever. Most people think their limited exposure to a topic, perhaps wit a bit of google on demand added in, makes them an expert.
What is your level of expertise Chris? Where do you obtain your primary sources? In my experience most primary sources (such as peer-reviewed papers) are published online and are thus available with "a bit of Google on demand". A short list of primary scholarly articles are often headed at the top of the front page of a Google search. Perhaps instead of calling out the entire comments section as idiots you could help out by suggesting some primary sources.
@@martinharris5017 you are trolling , people in comments are saying gravity, oxygen when the scientists int his same document are saying it was various things . If you think people arent being a bit dense you are naive.
Climate change is real, bro. Soon we’ll perish when the pollinators go as our Angiosperm-centric farms will not be able to reproduce (or you and your offspring will become slaves that do the pollination on those farms manually with tiny needles and no regard for your well-being). Choose what you want, climate change is truly dangerous to the stability of our non-slave economic system.
I don't really see why oxygen levels are considered the only reason that large insects don't exist today, why don't huge land animals the size of the dinosaurs exist today? That's not oxygen related. Different animals live at different times. Look at how big millipedes used to be, many hundreds of times heavier than they are now. If oxygen was the only factor then it would need to have been hundreds of times higher than it is now, it wasn't even double.
If it wasn't for humans, who's to say that elephants and rhinos for example, wouldn't evolve to become comparable in size, or even bigger than Dinosaurs given an abundance of food and habitat. Mammoths were relatives of the elephant and were larger than modern elephants. There is plenty of evidence to suggest that early humans hunted them to extinction with the help of receding glaciers. Further to your comment, consider the Blue Whale. It is the largest animal that ever existed, or so we believe... If so it could be possible that land animals may have gone through that evolutionary growth too?
Yes it is! That’s basic science. The reason different animals live at different times is due to the environment of that time & what it could support! Oxygen is the life flow of the blood down to cellular level.
Insects have an open circulatory system that is much less efficient than even that seen in mammals. Birds and Dinos in the same clad along with, crocodilians have the most efficient ones.
@@Bambisgf77 I don't think it is, it's not all about environment, mammals have been larger in the past and the environmental conditions are the same now. It takes time for animal's to grow to large sizes, thats why dinosaurs where the biggest in the cretaceous period. It makes sense that large flying insects aren't alive today as their oxygen need is greatest, but i don't see why large crawling insects couldn't exist with our current oxygen levels. If oxygen levels now are about 30% lower than in the past then if oxygen was the only factor then invertebrates should be only 30% smaller, but thats not the case.
I'm just guessing, but I imagine small insects ate the big insects. At least in some cases. In some cases, there just wasn't enough oxygen. Oddly enough, many extraterrestrials find oxygen fatality toxic.
หลายเดือนก่อน
I love me some science fiction down to the narrator So Called science. 55 million years ago and still sitting right there big as Stuttgart....😅😅😅😅 like COVID Vacine you on your tenth one😂
This is as good as it gets in the realm of biology documentaries. Everything we knew about giant insects 60 yrs ago, plus all the subsequent related discoveries and theories.
The animations, maps and use of scientific names are of universal appeal. We even meet the scientists themselves. 5 stars out of 5 ! And many thanks.
Thank you! We are glad that you enjoyed this video, this documentary is part of series from which we also published the second episode right here : th-cam.com/video/EC816OQPnjI/w-d-xo.html 😉
Why would humans not have survived in the high-oxygen climate?
@@ummeli2 I will venture an answer. Some level of carbon dioxide in the bloodstream causes us to breathe. Breathing high oxygen level causes hyperventilation decreasing that trigger and stops breathing to fainting or unconsciousness. BUT man being man, will have culture on its side. Technology. Breathing masks. Lol.
@@ummeli2 Because our bodies were not designed for it. It's weird to me too, like, we breath oxygen and it's a good thing right? But that's not the case, it's just something we know from grade school where you are taught "oxygen is good". Remember oxygen is just like any other element, and we have adapted to the lower oxygen levels of today. Back then, there were no mammals that could survive the high oxygen, and therefore the species that COULD grew to be massive. Adaptation is a strange thing my friend.
It's absolutely insane that pangea was a world of its own, like an alien planet...
to be transported to it would be like living in a dream... So cool
more like a nightmare
They became extinct because they were freakin' DELICIOUS!
19:34 *Giant Centipede* : "YOU SHALL NOT PASS!"
*Giant Amphibian* : [sad Balrog noises]
The most straightforward reason these (HUGE) insects ('simply') disappeared is for the same reason they APPEARED: the oxygen level of the planet's atmosphere. Since insects breathe through spiracles (tiny little openings in their bodies through which muscular contraction sucks air in and pushes it out, allowing them to inhale and exhale), the higher the oxygen level, the more capable they are of sustaining a large body. However, in an atmosphere such as ours today, it's impossible for the air to get into a 10-foot-long centipede and enable it to 'breathe'.
Simply put, less oxygen in the atmosphere means smaller insect bodies and higher oxygen means larger insect bodies.
There is ONE other vital thing to bear in mind: insects have exoskeletons, and as they get bigger, they need more oxygen, but at a certain point, the weight from carrying the support structure on the outside becomes too unbearable. In other words, there's the topmost limit an insect's body plan can reach-even in a highly oxygenated atmosphere. If I remember correctly, an experiment was done in which larval insects were 'raised' within a sealed, highly oxygenated structure and grew more significantly than usual. These insects couldn't survive outside of this very restricted environment...they were sort of the "insects in the plastic oxygen bubble" (if anybody gets that reference, give yourself a ⭐️😉).
Actually, there isn’t a consensus on this. Other studies show the oxygen level wasn’t that different from what it is today and may have even been lower. Stating this as a fact is misleading people.
do they breathe same way under water? 😅
What about the blue whale? Not alot of air under water, they do come up for air but what about that respiratory system VRS weight VRS energy requirements equals a massive need for air... Yet it defy evolution
Travolta’s role
@@ElectronFieldPulse no , for many millions of years before the Cambrian explosion ( which is when these super bugs arrived) the earth was covered in algaes , mosses and other primitive flora all photosynthesising. Inhaling co2 and exhaling oxygen. 13:16
what we have failed to address is there nymph stage? How much oxygen was in the water? The size of nymph will determine the size of the adult . These insects don’t live very long once they’ve reached this phase in their lifecycle. I don’t believe they grow any more. Perhaps the size was relevant to more of the aquatic environment and food source.
Can you imagine the buzzing sound from a 2 foot wingspan dragonfly? Terrifying.
The sound would be deeper, the frequenzy of the wings depends on the length.
A comment about the large insects of the Permian period. The hypothesis is that the action of flight also caused compression of the thorax, which pumped oxygen to other parts of the body. I can see a possibility in that for the adult dragonfly. But in it's nymph stage it would not have wings and therefore no pumping mehanism. The nymphs would most likely have had to have been of a similar body size to the adults. So the mystery is not completely solved.
An interesting aside is that due to the insects having an exoskeleton, there were also limits to their size. Their internal organs had to be attached to the outer exoskeleton. This also meant that they could not withstand sudden movements, or abrupt stops well.
Good Science ASMR for sleeping thanks. You pass the requirements - relaxing voice and music, interesting content, and over 30 minutes long.
Subscribed :)
😂😂😂
Oxygen makes the air flammable?!? Thats not how oxygen works…
It is though.
Things you think of as "flammable" are the rule not the exception in our Universe.
Most of the Universe is Hydrogen.
The majority of the planet mass in our solar system is "flammable", H2, CH4, NH3...
There is at least one major moon with lakes, seas, and icebergs made entirely of hydrocarbons.
There is even violent lightning.
But there is no fire out there.
Only here on Earth.
Because only here is found O2.
I LOVE these films! I remember the disappointment of so many adults that stuff like this was not available on the new miracle of TV. Think how smart we'd all be if quality learning shows had dominated TV shows like this?
These guys will do anything but work
It's a little-known fact that the insects committed suicide while their balance of mind was disturbed. RIP.
Oxygen was 35% and CO2 was 4000 ppm. Life thrived and species multiplied . Today oxygen is 21% and CO2 is 370ppm. Just saying.
But it was HOT and humid. Thus there were lots of large fern trees, etc. at the time. Wouldn’t have been pleasant living then. And the air was “extremely flammable”. So, maybe not a good atmosphere.
Life needs hundreds of thousands, sometimes millions of years to adapt to radically different climates. Also an enormous portion of Pangea was extreme desert. Depends on when in the Permian, but hot, arid desert would have extended up to about 30º latitude, north and south. If we did that again, almost all of Africa, all of India, and the most heavily occupied parts of China would all be hot, arid desert. If you're implying it'd be fine to return to those temperatures, a lot of people will die from drought, famine, or heat stroke, and many billions (with a b) would be displaced.
Insects do not breathe into lungs. They have tiny holes along the sides of their body is called spiritual and so the oxygen concentration is a big thing.
If the iron was oxidised in the red sediments, there must have been more oxygen in the environment than in the intervening middle Permian period. Why does that not explain the increasing size of the insects? The question should be why was there more oxygen at this period?
Nothing could break down the lignin in the plants yet. So all that carbon didn't turn to CO2. It turned to coal.
What does that have to do with anything?@@richardcrosswicks7058
@@ElectronFieldPulse- Red sediments should mean more oxidised iron compared to other times, so more oxygen. I am curious about the alternative explanation.
@@geoffreyM2TW - I just deleted my comment, I did not remember the paper correctly. The Carboniferous period had peaks and troughs, and in some of the troughs it did dip to today’s levels, but it also had elevated levels which reached the 35%. So, my statement about the whole period being that way was misleading. The thinking is that some of these insects seemed to have overlapped with some of the troughs so they are unsure about the relationship with insect size and oxygen level. It wasn’t quite as overarching as I initially claimed.
More plants to suck the CO2 out and bound it as lignin. Not much could decompose and release the carbon from it. All that carbon ended up as coal.
Looks like the Dragon Fly from the cartoon movie "The Rescueres." Came out in the late 70s.
@1:30 "Oxygen makes the air extremely flammable." And what is the fuel, nitrogen ?!
That has to be the stupidest . . now I can't believe anything you say, Goldberg.
The last I've heard on the Carboniferous period oxygen levels is that they weren't so different from current, rather similar.
I don't believe O2 levels is settled science.
7:34 While the models tjemselves look a bit plastic, the feeding behavior and interactiom between the two animals is very well animated. It looks like they studies real insect behavior to nail down the movements and feeding procedure.
After the fires slowed down the bugs were just like "how we gonna make smores now? No point in going on."
As far as I know was Arthropleura a millipede but its unsure when it split from others
It is not a dragonfly but a griffon fly, a cousin of dragonfly
Your house keeping was also involved 😊
Killing again for science!!!!! Dam you.
Why would they say humans could not survive in an atmosphere of 35% oxygen? We would do well under those conditions.
Oxygen is very toxic stuff . It's basically killing us slowly .
It has to do with the partial pressure of the atmospheric oxygen at that time (Boyle's Law). If the pressure and/or concentration of oxygen exceeds the equivalent of 23% at 1 Atmosphere (sea level on current day Earth) then human physiology and biochemistry starts to be affected. Prolonged exposure to conditions not optimal to humans leads to death.
Too high o2 in humans causes stomach distress and blindness.
@CharlesCurran-m9p People in hospitals breath 100% oxygen. Originally, the 1960s astronauts were going to go into space at 100% oxygen until a spark started a fire. Higher oxygen levels like what existed during the dinosaurs would be perfect for us.
@ I don’t believe patients in hospitals use pure O2 for extended periods but for COPD patients for example, sometimes do and that’s where the problems occur. That’s why they usually use 40% O2.
The mass extinction of 250 million years ago. What did that do to the giant insects?
How would you like to have one of those hit your windshield 😅
Допустим. Если ученые настолько уверены в своей теории почему не посадить мух дрозофил в герметичную камеру, создать там повышенную концентрацию кислорода и получить муху размером с кошку? 😂
If the oxygen level allowed these insects to grow huge. Perhaps the oxygen level lowered and cause the death of them
Insects did not die out, they just got smaller. Search their evolution.
Not many people know that the earth had a super continent in the carboniferous period and all the coal on earth was all laid down in one go all at the same time in the northern hemisphere. Also due to the increased oxogen content fires burnt much longer, further and hotter than in today’s climate and things broke down a lot faster as the oxogen caused oxidisation which meant organic matter broke down much quicker than in todays climate but unlike todays atmospheric oxogen content compared to back then it allowed insects and invertebrates to grow to super sized proportions.
The reason why there was so much oxygen was because the amount of plant grow was magnitudes greater than today because of the higher co2, about 10 times higher than today.
4000 ppm vs 370 ppm
Increasing gravity. That is not so hard to grasp.
🤣
They didn't die out! as the oxygen levels started to drop they got smaller. They became Dragon the flies we know today.
The carbo-nefarious period.
Damn! I don't feel bad for humans that are experimented on by Aliens anymore. I can hear that cricket now telling his friends and family how he was abducted and probed!
They were the drones of their time. Similar to drones currently revolutionizing warfare these creatures had no analogs and a huge advantage.
Jeremy irons?
Umm actually humans can live in that high of oxygen, people just don't have to breathe as much.
There are these things called red blood cells, your body produces less or more depending on its needs.
Starship troopers?
❤The old animal documentary crazy missed! No politics or woke sex references. We Need more of this❤
Insects are limited in size by their circulatory system.
At least human beings can't be blamed for that or the Dynosaurs .
Lack of oxygen kills most species
No one said one obv candidate, giant spiders maybe
Top of everest is 30% o2 less than sea level.
Why are they calling dragonflies Animals?
Insects and many animals were much larger before the global flood.
Is there enough water to have a global flood?
@ The oceans are as deep as commercial aircraft fly high.
*A GIANT SHOE!* 🥾
They didn't dissappear they adapted to the Lower oxygen Levels and got smaller surely like Mammoth did on Russian Island .
Oxigen levels are higher close to the ground!!! Never even mentioned!!!
💩 got funky and the giant insects couldn’t handle the funk.🤷🏼♂️
I don’t care what killed them, I’m just happy they’re gone.
Giant cans of Raid, that's what did it. It's all in my new book "Old Dead Bugs."
Whoops, high humidity lowers air density not increases it. US helicopters had lower lifting ability in Vietnam with its high temperatures and high humidity.
35% oxygen!
My Ducati Panigale would've put out 300bhp 🤪
Giant boots?
Giant Shoes.
so what your say that giant people GIANTs could be possible because the oxygen was 15% more . and that's what you think made dragon fly's giants .
A very, very, very big can of Raid!
Answer: Giant lizards XD
What killed giant insects ??
Come on man , that's easy. Same as kills little ones today.
Giant fish and giant birds 😅
Hmm
Opinion ,, Neither warer nor oxygen,, levels were the CAUSE.. HEAT WAS THE REASON
Giant can of RAID
Pure speculative bullshit on the flammable air. It was a hot sticky damp and swampy mess.
Syntethic voice?
No, it’s a real narrator. Not every clear voiced narrator is AI
oxygen in air? so why giant creatures in WATER also gone? (but better do not ask such questions 😂)
Where do you think the oxygen in the water comes from 🤦
actually the other way around, oxygen came from bacteria in the water, so o2 comes from the water not the air, 80% of todays o2 comes from the oceans
Insects? This documentary only mentions 2 giant insects
Giant cans of Raid.
DDT
We use the metric system now.👎
The idiotic comments here are proof of two things. Most don’t bother to actually read much, and don’t read primary sources at all ever. Most people think their limited exposure to a topic, perhaps wit a bit of google on demand added in, makes them an expert.
What is your level of expertise Chris? Where do you obtain your primary sources? In my experience most primary sources (such as peer-reviewed papers) are published online and are thus available with "a bit of Google on demand". A short list of primary scholarly articles are often headed at the top of the front page of a Google search.
Perhaps instead of calling out the entire comments section as idiots you could help out by suggesting some primary sources.
@@martinharris5017 you are trolling , people in comments are saying gravity, oxygen when the scientists int his same document are saying it was various things .
If you think people arent being a bit dense you are naive.
Dunning Kruger effect on full display.
Why do they make false baseless videos of persumptuouse ambiguouse speculation...
Because they can?
Oh no, not another evolution denier….
@@barriotoboardroom If you believe you came from maggots I wont argue with you....
Science is hard for some, and that’s ok.
Kek?
That last nonsense about climate, was enough. The scientists even said habitat loss.
Science is full of climate agenda
Climate change is real, bro. Soon we’ll perish when the pollinators go as our Angiosperm-centric farms will not be able to reproduce (or you and your offspring will become slaves that do the pollination on those farms manually with tiny needles and no regard for your well-being). Choose what you want, climate change is truly dangerous to the stability of our non-slave economic system.
I don't really see why oxygen levels are considered the only reason that large insects don't exist today, why don't huge land animals the size of the dinosaurs exist today? That's not oxygen related. Different animals live at different times.
Look at how big millipedes used to be, many hundreds of times heavier than they are now. If oxygen was the only factor then it would need to have been hundreds of times higher than it is now, it wasn't even double.
If it wasn't for humans, who's to say that elephants and rhinos for example, wouldn't evolve to become comparable in size, or even bigger than Dinosaurs given an abundance of food and habitat. Mammoths were relatives of the elephant and were larger than modern elephants. There is plenty of evidence to suggest that early humans hunted them to extinction with the help of receding glaciers.
Further to your comment, consider the Blue Whale. It is the largest animal that ever existed, or so we believe... If so it could be possible that land animals may have gone through that evolutionary growth too?
Yes it is! That’s basic science. The reason different animals live at different times is due to the environment of that time & what it could support! Oxygen is the life flow of the blood down to cellular level.
Because insects breath through holes in their exoskeleton unlike most vertebrates - oxygen content limits their size because of this.
Insects have an open circulatory system that is much less efficient than even that seen in mammals. Birds and Dinos in the same clad along with, crocodilians have the most efficient ones.
@@Bambisgf77 I don't think it is, it's not all about environment, mammals have been larger in the past and the environmental conditions are the same now. It takes time for animal's to grow to large sizes, thats why dinosaurs where the biggest in the cretaceous period. It makes sense that large flying insects aren't alive today as their oxygen need is greatest, but i don't see why large crawling insects couldn't exist with our current oxygen levels. If oxygen levels now are about 30% lower than in the past then if oxygen was the only factor then invertebrates should be only 30% smaller, but thats not the case.
I'm just guessing, but I imagine small insects ate the big insects. At least in some cases.
In some cases, there just wasn't enough oxygen.
Oddly enough, many extraterrestrials find oxygen fatality toxic.
I love me some science fiction down to the narrator So Called science. 55 million years ago and still sitting right there big as Stuttgart....😅😅😅😅 like COVID Vacine you on your tenth one😂