How can we increase animal size?

[Eagle9]

This is a continuation of my previous topic Is there any linkage between historic Oxygen levels in Earth's atmosphere and organism size?

So, let’s forget about primitive organisms and turn our attention to higher ones, for example rodents, primates

Are there any genes discovered that are responsible for their size? Rats in my laboratory (I made research on them) seldom grow more than 20 cm, but imagine that I want to have a rat of 60 cm long. What genes should be transferred into their genome? Has such experiment been done? Is it possible after all? If it is possible then we could make a King-Kong from an ordinary chimpanzee (and let’s forget for a while about the ethical issues), such experiment would be very interesting and outstanding, or maybe again nobody cares about such possibility?

 

[DaveC426913]

Is it possible after all? If it is possible then we could make a King-Kong from an ordinary chimpanzee (and let’s forget for a while about the ethical issues)

Never mind ethical problems - King Kong can't exist for many perfectly physiological reasons.

 

[jim mcnamara]

You are asking about gigantism, in part. The hormone somatotropin causes people and animals to be oversized at lot. So one answer is to change levels of this hormone in your rodents.
https://en.wikipedia.org/wiki/Gigantism

Physicians use this hormone to help patients with growth hormone deficits. -
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262362/

As @DaveC426913 noted - there are problems with mass increasing much faster than length, so that structures no longer support the animal.

 

[BillTre]

Breeding, over thousands of years has produced animals larger than the species from which they arose, for example some dog breeds are larger than wolves.

Gene manipulation has produced rapid size increases (in one generation) in some farmed fish, often from over expressing growth hormones or their relatives. These are not vast increases like King Kong, but maybe around 2x.

Making triploid fish (three sets of chromosome, rather than two) results in sterile fish. As a result they put their excess metabolic energy that would have gone into making eggs and sperm into body growth. Again not like King Kong.

Making smaller animals is something more commonly done (probably because its easier).

@DaveC426913's comment makes an important point. As organisms get larger, size effects will have to be compensated for (probably by additional mutations).

 

[jim mcnamara]

https://en.wikipedia.org/wiki/André_the_Giant Andre the Giant
Andre the Giant died at age 43, poor longevity , which is another issue with growing bigger too fast too soon.

 

[symbolipoint]

Not really a technical response, but the discussion reminds me of the known, intentional, crossbreed of the lion and the tiger. One of the results is a very very huge, oversized cat. This makes one wonder how well such a cat would do if it occurred in the wild. The overly gigantic cat did not evolve naturally, so this makes one wonder; advantages gained? advantages lost?

 

[PeroK]

Breeding, over thousands of years has produced animals larger than the species from which they arose, for example some dog breeds are larger than wolves.

Like this one?

 

[BillTre]

Not really a technical response, but the discussion reminds me of the known, intentional, crossbreed of the lion and the tiger. One of the results is a very very huge, oversized cat. This makes one wonder how well such a cat would do if it occurred in the wild. The overly gigantic cat did not evolve naturally, so this makes one wonder; advantages gained? advantages lost?

Also what niches could it utilize to get get what it needs to live.
When I see many of the super-sized animals of cinematic fame, I am wondering where would something like a King Kong (warm blooded, thus using about 10x the energy of a similarly sized cold blooded animal) get enough food in a day to survive. On the other hand, its poop deposits would be an impressive source of nutrients/fertilizer.

 

[symbolipoint]

Is what we see in post #7, a photographic trick?

 

[symbolipoint]

Also what niches could it utilize to get get what it needs to live.
When I see many of the super-sized animals of cinematic fame, I am wondering where would something like a King Kong (warm blooded, thus using about 10x the energy of a similarly sized cold blooded animal) get enough food in a day to survive. On the other hand, its poop deposits would be an impressive source of nutrients/fertilizer.

Yes I was pointing to things like that. Elephants are big, but they are grazers(or something that way). Extra gigantic big cats need to hunt something. Not exactly clear how they earn their daily living. That would be about question if they lived in the wild.

 

[DaveC426913]

...I am wondering where would something ... get enough food in a day to survive.

True. Although, considering the OP is talking about increased oxygen levels, we might not want to assume the biosphere isn't likewise unchanged.

(A triple negative is still a negative, right?)

 

[Eagle9]

DaveC426913

Never mind ethical problems - King Kong can't exist for many perfectly physiological reasons.

I want to know which physiological reasons prevent this


jim mcnamara

You are asking about gigantism, in part. The hormone somatotropin causes people and animals to be oversized at lot. So one answer is to change levels of this hormone in your rodents.
https://en.wikipedia.org/wiki/Gigantism

And it will help to boost a monkey’s (macaques for example) size from current 41-70 cm to let’s say two meters? It would be interesting to see such monkey

As @DaveC426913 noted - there are problems with mass increasing much faster than length, so that structures no longer support the animal.

I do not imply/plan to receive an animal of 100 meter size, but “just” to increase its size 2-3 times.

BillTre

Gene manipulation has produced rapid size increases (in one generation) in some farmed fish, often from over expressing growth hormones or their relatives.

So, if the growth hormones are the key circumstance then can we “feed” animal with them? This would be much cheaper that gene manipulation.

And which genes are involved in this process?

These are not vast increases like King Kong, but maybe around 2x.

This would be enough

symbolipoint

Not really a technical response, but the discussion reminds me of the known, intentional, crossbreed of the lion and the tiger. One of the results is a very very huge, oversized cat.

Who and when did such experiment? I can’t recall, perhaps I missed something?

 

[DaveC426913]

I want to know which physiological reasons prevent this

Galileo's Square-Cube Law. It's why ants have stick-legs while elephants have tree-trunk legs.
(It's also why elephants can't jump.)

Body weight goes up as the cube of the linear dimension, whereas strength goes up as the cross-section (square). Any larger and you can't have separate legs - you just get a slug-like critter.

It also has myriad consequences elsewhere, such as the surface area of the lungs, the pumping ability of the heart, muscle strength, etc.

The strength of muscles is proportional to their as the cross-section , so it only squares as the critters linear dimensions double - whereas the critter's mass cubes. At some scale, a critter such as Kong or Godzilla is so massive its muscles are maxed out simply holding its own body up and cannot lift anything more (see elephant jumping, above).

 

[symbolipoint]

symbolipoint

Not really a technical response, but the discussion reminds me of the known, intentional, crossbreed of the lion and the tiger. One of the results is a very very huge, oversized cat.

Who and when did such experiment? I can’t recall, perhaps I missed something?

Eagle9,
You'll have to just do some common literature searching to find the answers you want on that. Your community or any school library, good place to start. You can also do an information search through the internet and find what you are curious to know. Who first made such a cross-specie experiment? I don't know; only it has been done and results shown. You search!