/sci/ - Science & Math

>>6958125
high oxygen concentration

it make everything become bigger, since it's easy to make alle the body breath

life's scale (for macroscopics animals) is limited by the quantitie of organic matter one can get, but also by the possibilty to keep all the absorbed matter alive (like sending suffisent oxygen everywhere with the heart pumping)

>>6958125
>>6958127
if you don't already know this basic fact op why are you even on this board

>>6958127
what proof do you have that earth had higher 0s concentration?

>>6958187
Dinosaurs were able to dominate the earth for thousands of years.

PS you're a dipshit

>>6958125
Notice how they don't get much taller past a certain height, they just get longer and wider.

I don't see how it would matter what the O2 concentration was. Even today there's more O2 in air than mammals, birds and amphibians need. It's not like the dinasaurs locked themselves up in caverns for days at a time.

>>6958217
That's because you don't understand the difference between concentration and amount.

But how does having a higher o2 concentration lead to dinosaurs being so massively big? How was their heart able to sustain that sheer mass of tissue? That some insane amount of stress on the heart.

>>6958235
do you think dinosaurs had human hearts or something

>>6958187

>Insect fossils

>>6958225

How is that even relevent? If the concentration of O2 was a little higher back then it just means they had to pass less volume over their alveoli than they would now. It's not like lungs can't be larger proportionately in an animal that needs it.

And what does "amount" have to do with anything? You seriously don't think the entire sum of O2 in the atmosphere is going to change with every dinsaur breathing air, do you?

>>6958125
Blue whales are a lot larger than the largest dinosaur

>I thought it is biologically unfeasible for organic life to be too large.

says who? dinosaurs were clearly not ""too large" considering how long they were around. nor are today's large whales and other animals that are larger than the average dinosaur.

>thousands of years
i think you mean 165 million years.

>>6958187

Ice cores at the poles that haven't been melted in over 65m years can be extracted and have the bubbles formed in them tested for O2 concentration.

>>6959270
Poor example, in water that entire mass is suspended to some extent, in land creatures the mass will severely affect bones and muscle tissue. The bigger the animal the more stress there is on its body.

Although we do still have elephants who seem to be cooping ok with their size.

>>6959251
>>6958217

Not that anon but here's a link about the effects of oxygen levels on insects,

http://www.sciencedaily.com/releases/2010/10/101029132924.htm

Basically certain oxygen levels causes the bodies of insects like roaches and dragonflies to re-prioritize their own biology since there is a abundance or lack of breathable air.

It's possible that something similar happened to dinosaurs but in a more extreme measure where the genome itself went through a genetic bottleneck that influenced growth and was promoted heavily by an abundance of oxygen.

>>6958125
Earth had a lot less gravity back then.

>>6959343
you're confusing gravity's effect on size with O2's

>>6959356
no, fuck you

>>6959398
He's just avin a giggle.

>>6959432
/g/ is for giggles, /sci/ is for science

>>6959398
>>6959432
Its true tho. We know because the earth used to spin faster, and as it gains weight, it slows down.

>>6959462
fuck


you

>>6959470
Dude... over millions of years a lot of space dust falls down.

>>6959473
Plus every comet that came ever since the dinosaurs. Like are we really expected to believe they didn't add any weight at all?

Sorry, no thing comes from nothing just as no thing turns to nothing.

>>6959478
think of all the rockets and satellite we've sent to space though. And all the the lightweight elements that have escaped earth, like helium

surely it balances out

what was the largest living organism to ever exist? like, ever. And how large was it?

>>6959508
blue whale, look it up

>>6959506
>millions and millions of years of crap falling onto the earth
>less than fifty years of human space program, plus ...helium

are you even trying, dude?

>>6959511
are you?

>>6959510
wrong. there are clonal trees and mushrooms that are larger, both in dimensions and in weight.

>>6959510
heaviest ever, but not largest

>>6959508

And it's a mammal too. With lungs? Pfft...there goes that O2 theory. I don't even understand why anyone was spouting it.

There's also the problem of blood pressure differential between top and bottom parts of their body. What I can't get is their bone. How can their bones support their massive weight? One theory is there was less gravity/mass on the Earth back then.

The one theory that everyone ignores is....all dinosaurs lived in the ocean and had gils.

>>6959517
>heaviest ever, but not largest

PFFT. Blue whales weight nothing at all because their neutrally buoyant in the water.

>>6959945
they don't weight all that much relative to their size

>>6959508
The Great Barrier Reef, depending on your definition

>>6959957
by that definition I think it would actually be the entire country of Brazil. All the ground under Brazil is one single giant ants nest.

>>6959515
yeah, but trees are boring.
Whales do stuff.

>>6958125
Gravity wasn't as strong back then.

>>6958125
Back then, there was no burden of original sin on anyone's shoulders, allowing beings to grow larger.

>>6958125
https://www.youtube.com/watch?v=DkzQxw16G9w

VSauce

>>6958125

The biggest dinosaurs and whales are actually tiny compared to giant redwood trees. The biggest can grow to 390 feet high (no that's not a typo). That's taller than the goddamn statue of liberty.

http://en.wikipedia.org/wiki/Sequoiadendron_giganteum

>>6958187
Ice cords from the arctic and antarctic circles :D. Also yer mom told me after sex last night lol

>>6961418
The amount of NSFW content on this worksafe board today has surprised me.

>>6964190
That may be NSFW but I can't decide whether or not it's porn. I mean, there's a vagina so it should be porn, but it's almost like Japanese game show level of retarded, so I'm not sure if it actually is porn.

>>6958127
>>6958185
>>6958193
>>6958225
>>6958240
>>6959353
Oyxgen levels only explains the sizes of animals like insects that don't have lungs and have to supply their body with O2 by letting it in through their exoskeleton. In that case the issue is surface area to volume ratio; as a bug gets bigger, it's volume increases faster than it's surface area, meaning that after a certain point (determined by O2 concentration) it can't supply enough oxygen to its tissues anymore.

The issue OP is referring to is different. He's asking about why dinosaurs could get so big when they'd seemingly be crushed by their own mass. Weight is a function of volume whereas strength is a function of surface area (since the strength of muscle/bone is proportional its cross-sectional area). Once again, we have a volume:ratio rate of growth problem. At a certain point, an animal gets too big for it to support its own mass. Surely you've noticed this in day-to-day life; small animals can survive unscathed from falls that would kill larger animals. So you see, there's a hard limit imposed by gravity on the size an animal can reach. In the sea animals can get bigger than they can on land because of buoyant force, but there's still a limit.

>>6964234

I just furiously jerked my gerkin to this. Now, by definition it's porn. Hope that cleared up any confusion.

Best,
Jeremiah