How did my body know that my left and right hand are to be grown as mirror images of each other?



Same with feet, etc. Does each hand have its own gene(s)? Or is it one gene and then a flip switch that controls the other hand’s design?

In: Biology

>Does each hand have its own gene(s)?


We don’t actually *know* how genes work on this sort of “medium” scale as it’s incredibly hard to study directly and our computers aren’t powerful enough to simulate it, but since people exist with more fingers on one hand than another that’s a pretty strong sign they have different genes.

Oh and also, if you look closely your hands are likely very slightly different, but that could just as easily be due to random/chaotic motion of amniotic fluid as genetic differences (we know that genes don’t define the fine details of finger prints, for example, from twin studies).

There is a subgroup of genes called Hox genes. These are responsible for the body plan and making sure that your body expresses the correct genes at the right time and place by encoding for proteins that help with this process of development. These Hox proteins will interact with our DNA and special DNA segments to either promote or suppress gene expression so we have healthy and proper development (and not grow fingers on our feet or something like that).

In fact, it is well known that the Hox genes for body structures are ordered and organized on our chromosomes by their order of development.

There is a lot of work displaying this in drosophila melanogaster (AKA fruit flies), I’m almost certain that its where we discovered this group of genes as well.