How does natural selection account for the symmetry of the human body?

In a typical human , the following similarities may be quickly discerned:





The corresponding fingers of each hand (on the OPPOSITE side of the body) are roughly identical in length and shape; the same relationship exists concerning the size and shape of the hands, arms, shoulders, ribs, legs, knees, ankles, feet, toes, eyes, ears, and nostrils.





Additionally, the eyes and ears are located in the same relative positions on both sides of the face. Also, the corresponding teeth in the upper and lower jaw are roughly identical in structure.





What accounts for this symmetry?





God? Coincidence?

How does natural selection account for the symmetry of the human body?
Symetry is actually relatively easy to explain. It saves genetic coding space. It would be much simpler to just mirror the code as opposed to recoding the entire side. This would naturally be devoloped by natural selection as these species/lifeforms could not only breed faster but would have a higher likelyhood of successful dual sided mutation.
Reply:I wonder if the same symmetry can be found in cattle or monkeys!





Wow!





How Cosmic.
Reply:gravity





and one wonders why Galileo was hunted down...
Reply:Training helps.
Reply:Have you had a look inside your body lately? Ain't a whole lot of symmetry going on there.
Reply:using logic for you question,


why eyes is at the head.. to see thing as far as possible, for survival. there will be not much use if it is at your feet.
Reply:God is the answer
Reply:So... the implication is that symmetry can't have evolved. I'm sorry, I don't follow that logic.
Reply:genes


some people are more symmetrical than others


Like some women NEED to part their hair on the side..to like counter the assymetry of their bone structure..others(like myself :)) can part it down the middle, no prob
Reply:If you took a half-image of a person, copied it, flipped it, and matched it back to make a full image, you'd be amazed at how different it would look from the original full image.
Reply:Because a horribly asymmetrical organism would be unpractical, awkward and would have a hard time surviving unless the dimorphism is used in sexual selection ( fiddler crabs with one giant claw)
Reply:Well, I'm think walking around all lopsided wouldn't be very effective for hunting. Walking with a limp, awkward gait, one hand dragging on the ground the other up around your shoulders.





What purpose would that serve, certainly wouldn't be the most energy efficient for movement either. You would soon be caught by another animal, or terribly handicapped when it comes to hunting ...





That is what natural selection means... the best form for the best possible job...to ensure survival..
Reply:sounds like an intricate design





such designs require an awsome designer
Reply:Nature. You can say the same thing about the birds, animals, and even bug and insects. No big deal.
Reply:Whether you believe it comes from God or Evolution, you must admit it's present because it's beneficial. How is it beneficial? It takes less DNA information to be symmetric. We share similar base DNA win all life on Earth. Nearly all animals are symmetric, so it must be beneficial in nearly every environmental niche. It's only one plane of symmetry, a vertical center plane that goes between your eyes. It must not be good to be symmetric front to back for most animals. Most animals have a main direction of movement. Probably a connection there.
Reply:More interesting is how evolution accounts for the asymmetries. Your head is lopsided and bulges more over one eye than the other, the eyes are not the same size, one ear is located higher than the other, we nave to small of a jaw to fit all of our teeth into and often need our wisdom teeth extracted because of it. in most people the right leg is longer than the left leg....


....I think you are just using a made up argument about symmetry and suggest you actually check your facts instead of just believing what your preacher tells you.
Reply:Did you know that children respond more positively to women with bilaterally symmetrical faces, rather than asymmetrical faces?





Perhaps this is a key to attractiveness within a species... both human and nonhuman. Therefore, the more attractive or "symmetrical" a specimen is, the more likely it is to reproduce, and thus its genetics are passed on, making for symmetrical offspring.





Just a thought.
Reply:All living things have symmetry. The most commonly seen body style amongst vertebrates is that of the tetrapod, which include all mammals, birds, amphibians and reptiles. Some animal groups, such as the cetaceans, bats and most birds have been modified (e.g. front limbs become wings or flippers) but nevertheless, they are still tetrapods.





atheist
Reply:It takes less genetic information to make things symmetrical. That is why most animals have symmetry. It would only be problematic to the idea of evolution if we were symmetrical, and the other mammals weren't





And there is plenty that isn't if you look around your body..
Reply:It works better for humans than being asymetrical, natural selection. Founder and crabs benefit from being asymetrical.
Reply:Because a monkey with a gimp leg can't run away from predators.





But in contrast many crustaceons have different length and size forearms to handle different tasks.
Reply:What accounts for the fact that 90% of the GI tract is asymmetrical (stomach, pancreas, liver, gall bladder), and that the heart is off-center (and gee, there's only one of them)? And just where DOES that pesky appendix fit in?





God? Coincidence?
Reply:It doesn't. As some sci-fi writers have pointed out, any kind of selection could have worked up a more usable body. It does, however, point out that God is a God of order.
Reply:Logic dictates intelligent design.


I Cr 13;8a
Reply:Even going farther, how did the different sexes develop? Why aren't all asexual. This would be easier for evolution, but maybe it wouldn't as evolution has a problem of mutations, as most are harmful. As far as natural selection, I don't think there was a choice on symmetry. That makes me think of a cartoon in the New Yorker, as far as people dating on Halloween, ...enough said.


I believe it all comes down to a creator.
Reply:There is no coincidence with God.Everything is always where it is suppose to be.
Reply:GOD, If you read Psalms 139:13-16 it states, you made all the delicate, inner parts of my body. I believe that it didn't happen by chance.
Reply:God %26amp; God Alone!



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