Correlation between size and habitat?

[SFNQuestions]

Is there a field of study of or any correlation for the general size of an animal and the minimum size for an ecosystem it needs? Is there an answer in terms of differential equations for systems that involve a complex food chain?

Edited February 14, 2017 by SFNQuestions

[Zinalu]

When an animal doesn't have any threats it could evolve into gigantism, like the Komododragon, they started off as quite small lizards but due to the none excisting threats on that little island they grew large, often theres giving and taking in evolving and how they evolve depends on what the spiecies need, if a pray has many fast predetors, it's better to be fast and small, then you can run and hide inside bushes, trees, burrows in the ground etc, if your predetors are larger and strong but not so fast , maybe it's better to instead have horns and a large strong body, you will be slow but you can kick the threat, for the predator they might need to be fast and have strong jaws. So really theres some correlation but not neccesarily, in evolution it's more like "Meh this could do" then any proper correlation and since spiecies are evolving all the time they adapt all the time the best they can to their enviroment.

[DrP]

I think the maximum size of the animal depends more upon what weight it's frame can support more than anything to do with it's environment... (although environment can play a part if you go from land to water, say)...

 

For example - the largest dinosaurs (Argentinasaurus/titanosaur) we have found have been in south America - it is thought that these were the largest reasonably possible for a LAND animal of it's type - anything bigger and it wouldn't support it's own weight (just under 100 tons). For it to grow larger it would have to resort to living in the ocean, where the water would support it's weight.... but of course it is a land animal, not a water dweller, so that would not happen. The blue whale can reach nearly double this weight at max recorded size of around 200 tons.... that weight would not be sustainable on land.

 

PS:-I am not sure why poor Zinalu got -1 for that... although it doesn't directly answer the OP's question, it is not entirely irrelevant or wrong. I am no expert in this field though.

 

OK - Now I am thinking that my post is also irrelevant as it talks about the max size of the animal rather than the minimum size of terrain needed for a specific animal.... with regard to that I would expect that it is different for each species. I have heard that fish, for example, tend to limit their growth depending upon the size of the pond/lake they are in.... but the OP probably knows this and is looking for something mathematical, which I cannot provide..... *Invites -1 from the OP*.. although I have definitely heard of there being a minimum territory needed for certain animals of a specific size.... think I saw it on a documentary sometime in the past, but have no link.

Edited February 23, 2017 by DrP

[SFNQuestions]

I think the maximum size of the animal depends more upon what weight it's frame can support more than anything to do with it's environment... (although environment can play a part if you go from land to water, say)...

 

For example - the largest dinosaurs (Argentinasaurus/titanosaur) we have found have been in south America - it is thought that these were the largest reasonably possible for a LAND animal of it's type - anything bigger and it wouldn't support it's own weight (just under 100 tons). For it to grow larger it would have to resort to living in the ocean, where the water would support it's weight.... but of course it is a land animal, not a water dweller, so that would not happen. The blue whale can reach nearly double this weight at max recorded size of around 200 tons.... that weight would not be sustainable on land.

 

PS:-I am not sure why poor Zinalu got -1 for that... although it doesn't directly answer the OP's question, it is not entirely irrelevant or wrong. I am no expert in this field though.

 

OK - Now I am thinking that my post is also irrelevant as it talks about the max size of the animal rather than the minimum size of terrain needed for a specific animal.... with regard to that I would expect that it is different for each species. I have heard that fish, for example, tend to limit their growth depending upon the size of the pond/lake they are in.... but the OP probably knows this and is looking for something mathematical, which I cannot provide..... *Invites -1 from the OP*.. although I have definitely heard of there being a minimum territory needed for certain animals of a specific size.... think I saw it on a documentary sometime in the past, but have no link.

What's stopping an animal from simply evolving strong enough bones to support a larger weight?

[DrP]

They did - The Sauropods started growing massive, solid limb bones with really hard composite bone without the usual honeycomb structure that dino's often exhibit - but 100 tons seems to be the limit before it gets too expensive to support. This might be where your habitat limit comes in... if it isn't large enough to give enough food for continued growth. I do think that there is more too it than habitat though... even if Argentinasaurus had the whole planet to itself it probably wouldn't have grown much bigger, Not through lack of food, but down to the limit that calcium based complexes that form it's bones can take in terms of the stress from bearing the weight. To grow larger it would have to go into the water to take some of the load. I could be wrong about this - but this is what I have heard from conversations and reading around - I do not have a single reference for this.

 

I am not an expert in this field SFNQ - I just find it interesting, which is why I joined your conversation. I think the max weight for an animal is easier to explain when looking at spiders or animals with an exoskeleton. They are limited by the fact that they have no bones to support their weight, so this make giant spiders impossible as they would collapse under their own weight and burst. Unless you totally redesign them, then they stop being spiders I suppose.

 

I guess you could genetically design a creature which could grow bigger.... maybe you could get it to use minerals like titanium in their bones and have much tougher outer exo skeletal structure... but I am not sure we would want to do this as we could end up with Godzilla or something, lol.

[michel123456]

Is there a field of study of or any correlation for the general size of an animal and the minimum size for an ecosystem it needs? Is there an answer in terms of differential equations for systems that involve a complex food chain?

If I understand clearly the question, there are such researches about human development, for example the size of the land needed for a town to live.

But it is not related to the dimension of the animal (human size) but related to the population. A small village needs a smaller size of cultivated land around it than a city like New York.(a large city may need the dimension of a nation around it in order to fit its requirements).

I am not aware of such studies in relation of the animal size.

Edited February 24, 2017 by michel123456

[Moontanman]

What's stopping an animal from simply evolving strong enough bones to support a larger weight?

 

 

I think it's called the cube square law, there are real limits to how big an organism can get before it requires a radical change in it's form. Think of it this way, if a 2 meter man weighs in at 200lbs a 4 meter man of the same proportions would weigh in at around 1600 lbs but he would only have 4 times the surface area. Scaling up something results in real problems, this is even true for non living things. A piece of granite has a practical limit to how big it can be before it collapses under it's own weight.

 

On islands reptiles tend to get bigger while mammals that are normally large get smaller. Examples would be komodo dragons and pygmy elephants..

[SFNQuestions]

They did - The Sauropods started growing massive, solid limb bones with really hard composite bone without the usual honeycomb structure that dino's often exhibit - but 100 tons seems to be the limit before it gets too expensive to support. This might be where your habitat limit comes in... if it isn't large enough to give enough food for continued growth. I do think that there is more too it than habitat though... even if Argentinasaurus had the whole planet to itself it probably wouldn't have grown much bigger, Not through lack of food, but down to the limit that calcium based complexes that form it's bones can take in terms of the stress from bearing the weight. To grow larger it would have to go into the water to take some of the load. I could be wrong about this - but this is what I have heard from conversations and reading around - I do not have a single reference for this.

 

I am not an expert in this field SFNQ - I just find it interesting, which is why I joined your conversation. I think the max weight for an animal is easier to explain when looking at spiders or animals with an exoskeleton. They are limited by the fact that they have no bones to support their weight, so this make giant spiders impossible as they would collapse under their own weight and burst. Unless you totally redesign them, then they stop being spiders I suppose.

 

I guess you could genetically design a creature which could grow bigger.... maybe you could get it to use minerals like titanium in their bones and have much tougher outer exo skeletal structure... but I am not sure we would want to do this as we could end up with Godzilla or something, lol.

But I mean animals have adapted small amounts of all kinds of different elements and chemicals over time, like how for some reason people need iodine to avoid thyroids. The kind of adaption I'm thinking of is the one where adding a little bit of carbon turns plain old iron into strong steel. I'm sure there's some kind of combination of geometry and an element that would increase the load bearing capacity of a mineralized calcium structure.