So, now that I crept you out with the above picture, I better explain myself. This fly pictured above is known as a Drosophila fly affected by the Antennapedia mutation in its genes. This leg-for-antennas mutation is actually quite simply caused and something that can make us awe at God because of His creation.
While researching for this post I found the below statement made by the Biology Department in Kenyon College:
The homeotic genes encode transcription factors that control the expression of genes responsible for particular anatomical structures, such as wings, legs, and antennae. The homeotic genes include a 180 nucleotide sequence called the homeobox, which is translated into a 60 amino acid domain, called the homeodomain. The homeodomain is involved in DNA binding, as shown in the images below (to the side>>).
This all seems rather confusing but hold on for a minute as we will be explaining all this. First of all, we must understand that these homeotic genes are supposed to be in their certain part of the body. However, not all homeotic genes are model children and they occasionally get in the wrong part of the body during the embryonic stage.
So, when the body calls for the homeotic leg genes to make legs, they will do it. However, if those genes have somehow made their way to the place where the antennas are supposed to be then . . . you have legs coming our your head. This is very unfortunate for the fly.
But, interestingly enough, the fly is not the only creature with this problem. No, no, humans, plants and all kinds of other animals can have the same issue. And I wish I could keep going but one can only have so many hours in a day. Part 2 about homeotic genes coming soon.