So, in birthing the babies, it is seen as bloodshed. Perhaps, too, why it is commonly said to be the first murder. Within the blood of man is DNA. The key to knowledge (on many levels). The knowledge of good and evil and the tree of life are, or rather, can be quite complex and symbolic of many things. From geneological lineage to an unseen order of things, and yet a great many things in between, below, above, and beyond. With none of the interpretations being necessarily wrong in and of themselves.