Human Embryology 101

In another forum tonight, I read a juvenile argument that human embryos are no more significant than the cells of the cheek removed by scraping it with our fingernail. This is a common statement by someone who has read a little in some chat room, but who hasn’t had a serious discussion about humanity, much less engaged in a study of embryology or human ethics. This time, the young man went a little farther for shock value and noted the millions of cells lost by each of us when we have a bowel movement.

Let me refute this silliness with simple biology.

The cells of the cheeks and of the gut wall are specialized body cells at the end of their life cycle. They *are* no more and no less than epithelial cells. The same can be said for the oocyte and sperm if there is no fertilization. As they are, without intensive – and still highly speculative – technical manipulation, nothing can make them anything other than cells at the end of their life cycle.

The zygote and subsequent cells of the embryo *are* an entire, intact, developing human being who is functioning as he or she should at that stage of life. (Occasionally, in nature, the zygote may divide in such a way to result in identical twins, triplets or quadruplets, all of whom are entire, intact, functioning, and developing humans at that stage of life.) There is no “potential,” only an organism that *is* a human being.

Individual organisms rarely display all the qualities of the species at any one time in the life cycle. It’s true that a human embryo can’t breathe air or walk but neither can grown men or even post-menopausal women ovulate. However, “organisms” do function in an *organized* manner to develop and function as they should at any given stage of life for that species.

Humans are the only species which engages in the discussion about “rights” and which organisms within our species are human enough for their right to not be killed to be protected. This conversation is the essence of “human dignity.” I suppose that I shouldn’t be surprised that some humans don’t function at the highest level of human dignity and the conversation devolves so often into human *indignities* such as slavery, the deeming of women and children as chattel, and petty little comments that we were each equivalent to bowel movements at some time in our life cycle.