Why do people have 2 legs and 2 arms????
915737
the 2 arms is for hunting and gathering....and the 2 legs is for running away from enemies and dinosaurs....lol
865269
there is a two-way street involved in this question.....the taller, the more mass; the shorter, the less mass......so why do tall people run faster? because they have longer legs and their strides are bigger; however, tall people have more mass and therefore usually weigh more and that slows them down. Like in everything there is a happy medium which would be the fastest.\nFor the sake of the question, taller people will tend to run faster because of their longer legs and longer strides
885541
Q: Why do we walk on two legs?\nA: Because that is the way God created us.\n\nQ: Why have we lost our fur?\nA: What fur?  Human beings never had fur, unless you count hair.\n\nQ: Why have we developd such large brains?\nA: See A1\n\nQ: Why did we learn to speak?\nA: To be able to communicate with God.\n\nQ: Why did we learn to speak different languages?\nA: To be able to communicate with each other.
1004750
They use suction cups on their legs to crawl and the muscles in their bodies help them pull themselves along. So it may look a little funny to you but to them it is a daily must! I hope I answered your question!
389078
You mean "bipedal"?\nThey used their hands to hold tools, grab foods and so on. As time went by, they felt it convenient to use their upper limbs working instead of walking. And standing with two legs gave them a better vision ahead. Gradually, they stood up and walk.\nI am no expert. You should check it out youself in BBC or Discovery channel. They will give you a satisfactory answer.
436383
we used to walk on all fours (we were quadrapeds), but we evolved to use our thumbs. the reason is that we use our thumbs for work, not movement
161139
It's probably a wash. The weight of the body is distributed over twice the number of legs, so each leg has to do less work. More legs, though, mean that there's more energy required to move them all. The more legs thing could be cut down depending on the gait.
74218
It would need to be giant wings, and you would need to have a huge ammount of all arm muscles, but if you put huge wings on your legs too, it might be possible if you are coordinated enough.
686226
Because eventually your legs fall off. \n\nJust warning you...
15901
Because you don't have any hands??
362985
yeah ur question is a bit vague but im going to guess by saying that ur asking why we move our "parts" so much. frankly, the reason is because our "parts" hurt if they are not in a comfortable position.
15249
Humans - 4 when a baby (crawling around) 2 when all grown up 3 both legs and a cane!
176213
Because it's a number that works. First, our bodies are symmetrical from left to right, so we're going to end up with an even number of digits, lest we be lopsided. We also are grabbers, being primates, and so we need an opposable thumb, and at least one finger for that thumb to oppose. One finger and thumb really aren't that great for grabbing though, and unless that one finger was really strong we'd be falling out of trees left and right. Several fingers add the support and versatility we need. Obviously, while adding more fingers we're going to reach a point where we have too many, where they become cumbersome. Considering the size of our hands in relation to our arms (giant Mickey Mouse hands would be unwieldy and look weird), it seems that four thin fingers and one thumb works out just fine. There are people and other animals who get by with fewer (and sometimes, more) digits. Looking across the animal kingdom, this 5 digit construction is rather common, though not every species has an opposable thumb. Even animals without digits per say, still have 5 similar bones where the digits would be (like bats). That doesn't really answer the core question of why we have them, but it answers why the number we have works so well.
329278
Yeah !\nA Human Being !\n4 legs as an infant (Crawling on all 4),\n2 Legs as an Adult.\n3 Legs when he is Old with a walking stick(as the 3rd leg)
282850
If you had been born without arms and legs you would probably miss having them. Think about seeing all the other people that are born with arms and legs, seeing them walk, run, play, hug, etc. Now think about growing up without a Father and seeing all the other people with their Fathers, being able to walk and talk with them, receiving love from them, sharing your life with them etc. That's how you could miss something you never had.
429685
That's not necessarily true. It kind of depends on what side of your body you use most. Right-handed people tend to work the right side of their bodies more than the left side. So the right right side has slightly more muscle than the left therefore it's bigger. I'm right-handed, but I use my left hand for colorguard, rifle team and billiards, so my left forearm and hand are larger than my right. And, then again, humans aren't perfect. God (if you believe in Him) made us this way. No two things are exactly the same.
373950
definitely because of the sweating thing. Having a sag of skin that weighs a .5lbs to the inside of your leg isn't fun.\n\nAlso, it could be to readjust the Big Guy. He decides to grow @ completely random times, and if he's facing down (towards his feet) or straight out or to either side, he doesn't have much room to grow too! So you need to get down there and straighten out the situation before it starts to hurt too much. And after you do, well you're hand is in your lap already, do you have to move it? No. Then why move it? Leave it there.\nIt's not too complicated really.