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2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

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2385649 No.2385649 [Reply] [Original]

Hey /sci/.

What would it take for creatures and plants, even, to grow to such massive sizes? Say we as a species find a super-earth, much like the proposed Gliese 581 d, rich in life and liquid water, would the fact that the planet is larger effect life growth?

I know there can't be a definiate answer as of now, but is there any way to bring biology and physics together to solve this one?

>> No.2385657

>>2385649
If they breathe oxygen like most animals on this planet, a huge % of Oxygen in the air. Larger atmosphere would help a lot, possibly larger planet.

>> No.2385665

The largest animals on Earth existed at a time when there was far less atmospheric oxygen... or more correctly far more CO2.

More oxygen only equals bigger animals if the animals are somehow limited by oxygen, as for instance insects and arthropods.

>> No.2385669

>>2385665
Ah yes, i was thinking of insects sorry.

>> No.2385667
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2385667

Well OP, a planet with lighter gravity could certainly support lifeforms of larger size-and consider that this planet has had some fairly large land organisms, such as the larger sauropods, who weighed in excess of 80 tons and could be longer than 100 feet. A planet with half or one third our gravity could support vastly larger creatures.

>> No.2385676

Hey OP, read up on Cope's rule. Not really a firm rule, more of a suggestion...

But anyways, if you want larger animals, what you need are large quantities of low-grade fodder, being eaten by very large generalized grazing herbivores, which are in turn hunted by somewhat smaller predators.

That's about it, lots of not particularly nutritious food, and huge amounts of time for animals to adapt to eating it.

Lower gravity would help also.

>> No.2385683

>>2385649
A super Earth would have a higher surface gravity and thus it would be even more difficult for such a creature to maintain structural integrity. Such creatures would only be possible on lower gravity planets.

>> No.2385693

Low gravity combined with an oxygen rich environment and plentiful food ought to do the trick.

>> No.2385706

>>2385693
CO2-rich atmosphere and poor food sources works far better.

>> No.2385713

>>2385649
I severely doubt there will be many giant carnivores on any planet unless they eat huge amounts of something tiny like krill.

In all seriousness, organisms that grow to extraordinary sizes usually do so by being less dependent on any single part. They aren't what we generally think of as organisms but rather as groups of them.

If you'd like a planet with creatures that topple mountains by themselves, you're going to be disappointed, OP. In a planet with low gravity, a bigger creature wont necessarily be much stronger. It'll be a giant cow, basically. It just sits there an eats grass.

>> No.2385714
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2385714

What's /sci/'s stance on Jovian biology?

>> No.2385723

It saddens me to think that in my lifetime we won't discover new large land animals. God what I wouldn't give for scientists to devise a way for us to just LOOK at the surface of another living planet...

>> No.2385724
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2385724

>>2385713

>It just sits there an eats grass.

I'd be only too pleased with a super-cow, actually.

>> No.2385737
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2385737

>>2385724
¡Supercow al rescate!

>> No.2385745

With the discovery of bacteria on this planet that use arsenic in DNA bonds instead of phosphates, it kind of throws out preconceived notions of requirements for what "life" must be made up of.

Carbon based life forms are limited by gravity because carbon bonds are either soft or extremely hard and brittle.

Who is to say we won't find, say, a metal oxide based life form?
Such a life form may have been adapted with a structure that is more flexible and less prone to damage, thereby supporting a larger organism.

captcha:
scientific pitheis

SCIENCE!

>> No.2385747

>>2385745
Go read up about that study before you quote it ever again.

>> No.2385751

>>2385747
amen.

>> No.2385753

>>2385747
which one?
The most recent one about the bacteria in the lake proves that it IS probable that similar substances can be used.

I'm not saying it's arsenic based, it's still carbon based, but it's within the realm of possibility now that you can build life outside of the carbon, oxygen, nitrogen, phosphorus, and sulfur quintet.

We may see a life form that uses zinc oxide, oxygen, arsenic, and chlorine.

>> No.2385763

It could literally effect the size of animals in the family arthropoda. Considering that the amount of gravity determines their ability to grow under their own exoskeleton.

>> No.2385766

>>2385753
The study you're referencing was badly done. When it was reviewed, people said that it should never have been published.

Bad science, the entire thing. As far as I'm concerned, it's fraudulent and should be ignored.

>> No.2385770

I'd say oxygen concentration and gravity.
Higher gravity means higher oxygen concentration though.

So I doubt you'll see huge creatures.

>> No.2385772

Oh goddamn what was the name of that TV show that Kaku thought up aliens for? The big purple Lovecraftian thing with the yellow eyes?

>> No.2385775

>>2385766
Whether or not it was done perfectly, it still showed a bacteria using arsenic in place of phosphorus and not being killed by it.

It has opened a door to other possible elements being the building blocks of life.

>> No.2385785

>>2385775
>Whether or not it was done perfectly, it still showed a bacteria using arsenic in place of phosphorus and not being killed by it.

It did show bacteria living in an arsenic-rich environment.

It did not show bacteria using arsenic in place of phosphorus. It pretended that the bacteria were using arsenic because it was present, without examining the fact that phosphorus was also present in sufficient quantities to support normal cellular activity.

>> No.2385793

>>2385683
assuming same density

u r farther from the centre of mass though

>> No.2385797

>>2385785
It doesn't matter anyways and the study shouldn't have been a big deal, because anyone who thinks that something HAS to use our EXACT bio-chemistry to be alive is retarded.

>> No.2385798
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2385798

>mfw we explore a planet with 1/4 earth's gravity and are awed by the enormous creatures, only to then realize that our own gravity hardened bodies are immensely stronger and tougher

Time to become the alpha predator of this rock.

>> No.2385800

>>2385793
So I weigh less in an airplane than in a mine?

>> No.2385803

>>2385798
I call dibs on Dejah Thoris.

>> No.2385804

>>2385797
I agree. Just some friendly criticism of that particular "discovery."

Even if it wasn't rigorous enough, it's only a matter of time before we demonstrate the principle to be valid.

>> No.2385806

>>2385785
>http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry#Arsenic_as_an_alternative_to_pho
sphorus

>a bacterium, named GFAJ-1, collected in the sediments of Mono Lake in eastern California, can employ such 'arsenic DNA' when cultured without phosphorus.

http://www.nasa.gov/topics/universe/features/astrobiology_toxic_chemical.html
http://www.nature.com/news/2010/101202/full/news.2010.645.html
http://www.ironlisa.com/WolfeSimon_etal_Science2010.pdf
http://www.space.com/scienceastronomy/arsenic-bacteria-alien-life-101202.html
http://www.nytimes.com/2010/12/03/science/03arsenic.html

>The microorganism substitutes arsenic for phosphorus in its cell components.

Bitch.

>> No.2385811 [DELETED] 

>>2385803
I just read that book last month after grabbing it from Gutenberg. Glorious.

>> No.2385812

>>2385803
I just read that book last month after grabbing it from Gutenberg. Glorious.

>> No.2385813

>>2385811
Gutenberg is glorious.
Better than Wikipedia, in some respects.

>> No.2385814

>>2385813
What the fuck happened there?
Did you delete your post and make a new one while I was typing that, with impeccable timing?

>> No.2385820

>>2385806
No, the other guy was right- that study was flawed.
If you read the study they said that arsenic was likely to be present in very small quantities in the DNA- the vast majority of the DNA was phosphorus bound.
Arsenic forms weaker bonds to oxygen than phosphorus does, and the arsenic enzymes are there to prevent it from dying.
Either way, 99% of the DNA is phosphorus.

>> No.2385817

>>2385800

Yes, you do

>> No.2385818

>>2385814
I somehow managed to fuck up and double post. So I deleted one.

I just find it odd you didn't see them both... Talk about timing!

>> No.2385823

>>2385806
>The background PO4 3- in the medium was 3.1 (± 0.3) μM on average, with or without added AsO4 3-, coming from trace impurities in the major salts (11) (table S1).

What does all that mean exactly, bitch?

>> No.2385833

>>2385817
hory shit.

I don't know how I've failed to realize that in all my years of education...

In fact, I HAD to know about it, as I was aware that clocks record time differently at different elevations, time dilation and all, but I never realized that specific implication.

MIND BLOWN.

>> No.2385847

>>2385649
OP are you talking about some kind of sci-fi book this concept comes from ?


If so I'd like to know about it, and get a name because it sounds interesting.

>> No.2385857

>>2385833

You would weigh the most on the surface, in a mine the rock above you would slightly counter the gravity below you. You would also float if you were in the center of the earth since gravity would be equal in all directions.

>> No.2385861

A planet with higher gravity would be more likely to give rise to shorter, stockier creatures with dense body structures. Not mega-creatures.

>> No.2385863

>>2385800
yes you do.

surely you know gravity is related to distance

>> No.2385865

>>2385857
I knew that, oddly.

>> No.2385868

>>2385863
Yes. Just a failure to make obvious connections; too much LSD or something.

>> No.2385876

>>2385868
One time on lsd, my mind turned into cooling lava.
It was the most inexpressible thing. Thinking was this sort of shifting, grinding motion amongst "compartments" of semi-molten rock, suspended in a thick liquid. Sensations were like pressurized leaks spurting out the sides of this whole mess.
Thoughts were positions.

>> No.2385883

>>2385833
hypothetical question

man builds tower 2000000000km tall on earth. u are on top of tower. gravity still = 9.8m/s2 ?!?!?!?!?!?

>> No.2385902

>>2385883

Go to bed Timmy.

>> No.2385907

It is a hard question to answer, because what is massive? Are we talking relative to humans or solar systems or even galaxies? I have no doubt that their is intelligent life out there that could be 100 times the size of humans and some that could be microscopic to humans.

Which makes the whole massive thing a bit up in the air, because what is "massive"?

>> No.2385910

>>2385857
Question, what's at the center of the Earth then?

I've long considered that there shouldn't be a huge mass of iron in the middle of the planet, and am considering cutting open Venus to find out.

>> No.2385914

>>2385868
fuck me
is this a rare case of, 'i accept accept i was mistaken' wouldn't happen on /b/. only on a sci page. notify moot - meme

also - not trolling - why would higher O2 make smaller animals!?? re: previous posts dinos were in higher CO2 environments hence bigger

>> No.2385917

>>2385907
eh, i'm not sure about "microscopic"...
I don't think that life would be able to fit in all the required complexity for "intelligence" if it were that small, whatever "intelligence" is.

>> No.2385932

>>2385914
Higher CO2 makes faster growing plants.

Faster growing plants have less nutrients per/weight. (nutrient dilution)

Less nutritious plants require more eating to get the same nutrients.

More eating requires more digesting.

More digesting requires larger guts, thus larger animals.

More digesting is also more efficient at larger sizes.

Larger herbivores result in larger predators.

So more CO2, and thus less Oxygen, results in larger animals.

>> No.2385929

>>2385914
Dinos were in higher O2 concentrations though. Hence shit like giant dragonflies- the increased O2 concentration allowed them to fuel their giant wingspan

>> No.2385935

>>2385929
dinos were in lower oxygen concentrations, and didn't live at the same time as giant insects.

>> No.2385939

>>2385883
Yes, Earth is still pulling on you at 9.8 m/s2. However, the gravitational pull of other bodies is stronger now, and the net effect is smaller.

I actually have no clue, I'm just talking out of my ass. Can anyone confirm this or am I retarded?

>> No.2385941

>>2385932
..You could have both

>> No.2385946

>>2385941
not as a percentage. which it is.

>> No.2385949

>>2385941
More carbon dioxide AND more oxygen?

A denser atmosphere?

>> No.2385953

>>2385910

Something very dense presumably.

Of course you would only float if there was an air pocket. If a tunnel was made through the earth and it was made into a vacuum, you could accelerate to extreme speeds and perfectly decelerate back to the other surface of the planet.

>> No.2385957

>>2385949
Less nitrogen?
Hell why not a denser atmosphere, for all we know the atmosphere was a lot less dense back then and the atmosphere we have now is actually really dense.

>> No.2385959

>>2385949
Maybe just less Nitrogen.

>> No.2385962

>>2385917

Well, it all comes down to relative sizes again, if we were to encounter a super massive alien species from some super massive galaxy with super massive planets, and the creatures were literally 1000's of times the size of us, we would be microscopic to them.

In Hitch hikers guide I remember about a part where some aliens got offended by a conversation they overheard between 2 humans? I cannot quite remember, so they set out to invade but when they got here they were so small in relative size that the whole invasion force got eaten by a dog or something along those lines (it was a long time ago I read the books), I thought that would be quite a fitting anecdote for this subject.

>> No.2385964

>>2385957
>for all we know the atmosphere was a lot less dense back then

except gasses trapped in paleosols mimic current density.

>> No.2385966

>>2385957
...faggot.

>> No.2385968

>>2385964
Yeah, sorry.
I said something extremely dumb.
So what did these trapped gasses say about the CO2 and oxygen ratios?

>> No.2385970

>>2385962
Yeah, two alien races went to war against each other for a perceived slight that was actually a human word that slipped through into their worlds. After a gruesome war, they realized what was up, and came for us. And their entire armada was eaten by a dog.

Belgium?

>> No.2385973

>>2385962

I think it's more likely that those super massive planets don't evolve life at all.

>> No.2385976

>>2385970

Haha yeah, that's right, what a great book that was.

>> No.2385980

>>2385968
I'm only familiar with a small portion of the Kimmeridgian-Tithonian... though that happens to be when the largest dinosaurs lived.

CO2 ~6x current values, (~1800ppmv) and available O2 reduced by that value. If I remember correctly, which I may not...

>> No.2385981

>>2385973

Moat likely they do not if they are gas giants, but we never know what is lurking out there in the universe.

>> No.2385993

>>2385981

Any interstellar space faring race would most likely have abandoned their biological forms long before for much more capable synthetic bodies. The physical limits on those would be far lower.