Friday, July 18, 2008

The Stem Cell Debate

Caution: The following offering is lengthy.

I’ve been reading a book that is changing part of my thoughts about abortion. The Stem Cell Debate, by Ted Peters.

In college I studied early human embryos in some detail. When the egg and sperm meet the new zygote has a unique genome, which is its own individual set of genes that are similar to each parent but not exactly like any other human that has ever been. Since my college days I have considered the zygote to be a new human being.

Certainly the woman/mother has the right to do to her body what she wants. It is her body. But when she is pregnant she is not the only one, she is not the only human body that is directly involved. The woman has a right to decide what happens with her body. I have also always contended that the developing embryo, the new human, has just as much right to make the decision about what happens to its body as does the woman who is carrying it. I have always thought that the woman gets to decide, but after she is pregnant it is too late to make the decision because by then it is a group decision, hers and the new human inside her. “Go ahead, woman, make the decision about whether or not you want to be pregnant, but do it before the new human is living inside you” has been my response.

The book I have been reading concerns the ethical and moral choices that are involved in stem cell research. It is quite technical, using scientific language to describe events and relationships. I haven’t read good, technical, biology books in many years, so it is pleasant to dig in to it again. And, reading this book has resulted in me changing my opinion in some respects about the role and rights of the zygote-embryo-new human.

When the zygote (the new human embryo) is a single cell, yes, it contains a unique genome. When it divides into two, and then four, and then eight cells, each of those cells contain the identical genome, as will every nucleus in that human being when it is an adult. (Yyeee, wellllll, pretty much anyway. As our bodies age, with millions, billions, and trillions of cell divisions, some errors do crop up. No doubt in my body some of the nuclei have splintered chromosomes and some genes have mutated. That, too, is part of life and of aging.)

At the two-, or four-, or eight-cell stage there are times when the cells do not remain glued together. If they separate into two groups of cells, then, if both develop to the maturity of birth, there will be identical twins born, two kids with identical genomes. Rarely, but occasionally, the embryo, before the blastocyst stage (the little ball of cells that is somewhat like a tennis ball with one side pushed way in, making kind of a baseball catcher’s mitt, or a sack) the cells come un-glued and create three, four, or more identical twins.

Ted Peter’s book cites evidence that until the embryo is implanted in the uterine wall, and has developed the primitive streak which will become the backbone, at 12 to 14 days, the embryo retains the ability to separate into more than one individual. After implantation the ability to separate into more than one individual is lost.

If, at conception, when the sperm and egg join, there is then a single human being, what happens when that embryo divides and makes more than one human being? They are not still one individual. (They are a committee, or at least a community!) My thinking is changing –how far it will change I do not yet know—I’m thinking that perhaps the embryo before the primitive streak at 12 to 14 days, may not be an individual human, only a unit that has the ability to become a single human being.

This author describes another aspect of the developing embryo. At our present understanding of embryology the zygote grows to the blastocyst stage (the ball of cells that is folded in and his inner cells and outer cells, which is the very beginning of cell differentiation in the developing embryo), then it stops growing. From this stage in development the blastocyst needs to implant in the uterine wall, then receive hormones from the mother before it will continue to make more cells, to develop, and soon reach the primitive streak stage on its way to becoming a baby.

Another question concerns ensoulment. When does the developing baby develop or receive its soul? (Big and important question.) Certainly to me, once an embryo has a soul it is a valued, human being. When does that occur? If it occurs back when it still can divide and become more than one human being, then both twins, or triplets, or whatever, would have the same soul. I don’t think that will work. So ensoulment must occur sometime after conception.

Certainly to me, once an embryo has a soul, it is as valued as is the woman in whom it is growing. In the days, months, and years ahead I hope to figure out when ensoulment occurs. Knowing that will certainly help me know when a unique new human exists. Knowing that will help me decide about stem cell research as well as my opinions on abortion.

Others have told me, at various times over the years, that the thing growing inside a woman during pregnancy is not a human until it is born. Up until the time of birth, as I understand the thinking of those who have told me this reasoning, a woman can abort the fetus and not cause harm to human life because it is not yet human.

To that argument I have a couple of replies. My aunt was born six weeks prematurely. Does this mean that she was not a human at birth? Did she get to become a human being six weeks before others have? Why do women mourn the loss of a thing, when there is a miscarriage and the fetus dies before birth if it is not a human yet? The description of it not being a human until it is born does seem reasonable to me.

Today I am thinking that the developing life inside a woman becomes a human at the time of ensoulment, when the soul enters the embryo. I don’t know yet when ensoulment occurs. I am leaning toward accepting that ensoulment occurs around the time of implantation in the uterine wall.

If the blastocyst, that occurs prior to implantation, does not have a soul, and can divide and create more than one individual human, then it seems to me that stem cell research can proceed on the cells before implantation.

There are some other concerns. The “harvesting” of egg cells is a difficult procedure. To get eggs out of a woman is pretty tricky, risky, painful, and has other complications. The obtaining of egg cells from a woman is part of stem cell research and needs to be considered carefully so that we do not abuse or take advantage of women, especially poor and desperate women who may accept harvesting of their eggs for poor reasons such as for money, or through intimidation. Another concern is who will be the beneficiaries of stem cell research. Will the benefits be available only to rich white people, yet again taking advantage of those who are not rich and white? Or will the benefits be available equally to everyone? Because there is so much money, huge piles of money, involved in this research, and the early results will be very few, it will be difficult to offer the results in an equal manner.

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