Why are mammals stuck at 4 limbs?

Why are mammals stuck at 4 limbs?

>mammals
You mean vertibrates.

No I mean mammals. Fuck off you pretentious cunt.

>he thinks snakes have 4 limbs

Because evolution is driven by random mutations that are then passed on because the organism successfully reproduces.
So, that means either it occurred and didn't successfully reproduce or it didn't occur and thus couldn't be reproduced.

We aren't "stuck" at 4 limbs. It's just that we have no need to evolve more as our environment isn't requiring it.

no the real reason is because once you evolve a structure it becomes very difficult to unevolve it.

You can normally only change parts of it's shape gradually.

Would the tail of a dog, cat, monkey etc qualify as a limb?

Because all terrestrial vertebrates have a common ancestor that was a fish with 4 lobed fins with a recognizable arrangement of bones thats immediately identifiable as having the same bones as all other vertebrate limbs. Like the Humorous/Femur the Radius and Ulna/tibia and fibula, the wrist bones, and phalanges.

>Would the tail of a dog, cat, monkey etc qualify as a limb?
An appendage.

i made this thread a while ago
it's a really good question

Snakes are "unevolved" lizards though.

Meme answer: We won't be for much longer if people keep eating GMOs and don't start believing in global warming.

Real answer: Because humans with more than four legs have some trouble reproducing. Probably them not surviving long/no one wanting to mate with them/being unable to secure resources (food/sex) above and beyond people with only 4 limbs.

>he doesn't know that snakes develop 4 limbs in their gestation period and that the genes that control their development shut off after tiny limbs have formed, causing the limbs to atrophy and disappear but keeping some of the underlying anatomical structure still around due to the initial development of the limbs.

Brainlet.

The difference being...?

>humans with more than four legs
Please do not make further posts.

>IalmosthadtocomeupwithacounterarguementbutIseehereyoumadeagrammaticalerrorsoitlookslikeIwin.jpg

Whatever your ancestor has after around 500,000 years becomes a permanent feature in your future design meaning you will never ever mutate a new limb into existence and are stuck with four FOREVER.

>Reply to this post or your mom will dye her hair blue tonight.

Because it's impractical.

Here, for the human arms to work requires a brace (the shoulder bone). If i had a second pair of arms further down my back, i would need a second shoulder bone, but now it is in a location that doesn't have as much support (the spport of any bach, shoulder, or neck muscles) so now it is compromising. It would also probably get in the way of some average human functions.

Likewise with other animals, isects due to their rigid chitnous exoskeleton are only able to move practically with 4 or more limbs. Mammals are only able to move practically with 4 or less limbs.

says who

That's not a grammatical error you retard. Please come back when you're 18.

monkeys have 5 limbs.

You damn well know I meant 4 limbs and not legs. It's a minor error. But keep posting.

I dont know about you but I have 5