the simplest body plan for a motile animal is a radially symmetric tube with a mouth at one end, a gut in the middle, and an anus at the other end (a worm)
this biases animals to having a front and a back
once animals get big enough, gravity starts to become an issue
this biases animals to have a top and a bottom
there is no external pressure to differentiate left and right, so most animals have bilateral symmetry

internally, animals are often asymmetric to some degree because the important thing is to pack all the organs needed in a space efficient manner

>>17050384
If something works and is good in one direction, then it aught to work and be good in other directions. Radial symmetry is even better than bilateral symmetry if it wasn't for the need of moving creatures to have a single dedicated "front".

>>17050392
>If something works and is good in one direction, then it aught to work and be good in other directions.
Is this how gays evolved?

>>17050392
[math]redundancy has to be a thing here as well[/math]

>>17050384
it's a mirror thing

>>17050384
>take a thing
>divide it
>you now have two mirrored things

>>17050787
Does the symmetry also result in needing fewer genes to describe the body layout?

>>17051046
You need extra genes to describe symmetry as opposed to just growing where nutrients are

>>17050384
it's simpler to store information about one configuration and duplicate it that to store information about two separate configurations

Question! Sometimes there's mutations when one hand is missing, or somehow else body becomes asymmetrical. Does it mean that there's two sets of genes for every side, or there's one set but it has broken in the process only for one side? Or genes work completely different from my understanding?

Another observation. There's mutations, when some part of the body is doubled, for example a tail. Does it means that body in general is very prone to bilateral symmetry?

>>17050407
Mental illness