What are the mechanisms that ensure consistent left-right asymmetric placement of various internal organs (heart, liver, etc) or consistent left-right asymmetric development of paired organs (brain, etc.)? At what level, and how comprehensive is our current understanding about the underlying mechanisms?
(It seems to me a mirror image is just as good as the original one in terms of fitness and functionality. But why only one specific LR asymmetry prevails? Maybe this is a misguided way to think about the problem but that motivated to ask anyway.)