During mammalian embryogenesis, determination of three body axes takes place. First, the embryo assumes an AP axis, soon to be followed by the development of the dorsal-ventral axis. Then, after quite a delay, the third and final symmetry break happens: that between left and right. The node coordinates determination of the left-right body axis. Read more
When one thinks of the implications of being a righty or a lefty, writing comes to mind pretty quick.
Did you ever consider eye dominance? When you take a picture, you bring the camera towards one eye so you can truly see what you want to photograph. Read more