ZedTT t1_j9fnq8p wrote on February 21, 2023 at 4:11 PM

Reply to comment by LifeBuilder in TIL that ligers (the offspring of a male lion and female tiger) are the largest big cat because, unlike lionesses, female tigers do not possess growth-limiting genes to counter the growth-maximising genes of male lions. by argh-ok

Not exactly. The square cube law makes larger life unviable and makes evolution naturally select against animals that are too big. In this case, though, evolution isn't really at play as these are artificially bred animals.

Evidently there is some square cube law wiggle room above the size of large cats, hence ligers don't drop dead from overheating or being unable to stand etc. They may be overall less suited to their environment, though.

Bloomberg12 t1_j9h1fs8 wrote on February 21, 2023 at 10:37 PM

There's also other limiting factors in size too, to be fair. Cancer being one of them, with a lot more cells to undergo regeneration the chance that one "goes rogue" becomes much more likely, especially since life spans typically become longer when a longer growth period is needed.

That being said some animals have developed counter measures like elephants that makes them much lower risk.

ZedTT t1_j9ii5k7 wrote on February 22, 2023 at 5:15 AM

Thanks - I was sure I wasn't being exhaustive.

fanghornegghorn t1_j9rp97u wrote on February 24, 2023 at 2:03 AM

Elephants don't get cancer?

Bloomberg12 t1_j9s91b3 wrote on February 24, 2023 at 4:39 AM

Very rarely, especially so for their size and life span.

They have 20 times the copies of a fairly common gene (P53) which targets cancer cells and this is seemingly pretty common for larger animals including blue whales but elephants specifically have another gene (LIF6) which is controlled by P53 and acts as another layer of defence. It's also a theory that it was a strong contributing factor as to why elephants got as big as they are because of the (extremely vague) timing.