Tag Archives: Person

Genetic Identity & Chimeras

Details of bony structures in 14-week-old fetus from an ultrasound equipment manufacturer.

If you’ve followed this blog for long, you know I am pro-life, both on religious grounds and on scientific grounds. In a recent discussion on Twitter, I made a point I have made before, that the fetus cannot be a part of the mother’s body (as many pro-abortion advocates say), partly because the fetus has different DNA from the mother. Later in the discussion, an objection was raised to this point that I hadn’t heard before, so let’s work through that today.

For those who may have been living under a rock the last 60+ years, DNA is the complex molecule Deoxyribonucleic Acid found in every living cell that stores the “blueprint” for that person. First discovered in 1869, it’s structure was finally determined in 1953, and the staggering informational content fully mapped in 2003. After that slow start, our knowledge about DNA and uses for that knowledge have increased dramatically over the years. Some of the most common uses of DNA testing include determining parentage, convicting guilty criminals (or exonerating those wrongly convicted), and identifying partial or unrecognizable remains. Essentially, these examples use DNA to verify the unique identity of individual persons. Now combine that with the well-established fact that by the time fertilization is complete (within 24 hours of the joining of sperm and oocyte), and while still only a single cell, a developing baby has DNA distinct from either parent. The obvious conclusion, biologically, is that this rapidly developing organism is not the same organism as the mother.

Now, the objection raised was that unique DNA doesn’t determine how many lives are present because of the existence of chimeras. What’s that, you ask? A chimera, outside of the mythological monster from which the name is drawn, is an organism with two (or more) distinct sets of DNA. Though not “new” in terms of existence, the first confirmation of a natural human chimera was in 1953 when a woman in England donated blood and it was found to contain two different blood types in one sample. As our knowledge of genetics has grown and DNA testing has become more commonplace, so too has observance of this phenomenon. for instance, a woman needed a kidney transplant in 1998, but when her 3 sons were tested as potential donors, 2 of them were determined, based on DNA, not to be her biological sons, even though she had given birth to them. Then in 2003, a woman in Washington filed for welfare benefits for her children and was denied, with accusations of welfare fraud pending, because her 2 children were determined not to be hers. A 3rd child was born while this was being investigated, so that birth and an immediate DNA test of both mother and child were witnessed by an officer of the state. Again, the DNA test showed different parentage for the child just born. What happened in each of these cases? Each of these 3 women had been twins. The Englishwoman in 1953 had a twin brother who had died shortly after birth. Cells had been shared between the two early in the pregnancy. The other 2 women were both the result of fused embryos, or a “vanishing twin”. Two oocytes had been fertilized by two sperm, resulting in twin zygotes. Early in the pregnancy, however, the two zygotes merged into one. Because they were separate zygotes, they each had different DNA. However, because this occurs very early in development, the zygote is still a collection of totipotent cells (meaning each cell at this stage can still become any cell in the human body, i.e. they have not differentiated into their separate lines of specialized cells for organ generation). When the twin zygotes (call them A & B) fused together, some of the cell from twin A went on to form various body parts like the skin cells inside the cheek where DNA samples are often taken. Cells from twin B went on to form other body parts such as the ovaries that would be responsible for producing children “not her own”. A third scenario, Fetal Microchimerism, or FMc, is much more common and is when cells from the blood of the fetus and/or mother get through the placental barrier to reside in the other person. Cells from their children have been found in the bodies of autopsied women many years after their pregnancies.

Based on these observed cases, we know that a person can have multiple DNA. But does the existence of chimeras refute the idea that the developing baby is a unique individual distinct from the mother? I don’t think so. After all, when a patient receives an organ transplant, the donated organ will have the donor’s DNA rather than that of the recipient; but nobody considers the donor and recipient to be part of the same body. Furthermore, even though the person may have 2 sets of DNA in their body, the transplanted organ is only one organ, and cannot become anything more. A zygote, on the other hand, is capable of developing into a mature human, and is, in fact, directing much of the pregnancy. The case of cells passing between twins in utero, as in the 1953 English case, is really no different than the case of organ donation between adults. The case of fused zygotes is more extreme in that all of the “donor” has been passed to the recipient, but the concept of a donor providing some portion of a recipient’s organs still applies. Because the transfer of genetic information occurs at such an early stage, it’s impossible to know which organs formed from donor and which from recipient without some kind of comprehensive test that is not practical at this point, but it’s important to remember that neither zygote had the same DNA as the mother, so the resulting chimera is still not part of the mother’s body no matter how you look at it. As far as fetal microchimerism, we are only talking about a few individual cells from a genetically unique human (i.e. the baby) passing through the barrier that normally separates the baby’s blood from the mother’s, and residing in the body of another genetically unique human (i.e. the mother). The fact that a few of the baby’s cells migrate into the mother’s body (and vice versa) no more make the baby part of her body than an organ donor’s cells inside a recipient’s body makes the donor part of the recipient.

Does the chimeric objection succeed? No. Even with individual persons not necessarily being limited to only one DNA in their body, the baby is at all stages of development a separate, self-contained organism temporarily residing in the mother for nourishment and protective environment, and not a “part” of her that just has different DNA. All cases of chimerism, both natural and artificially induced, come about from the involvement to one degree or another of a second, genetically distinct organism. The different DNA confirms this and actually bolsters our understanding of a baby as a genetically unique individual from conception.


Further reading: “The Human Chimera: Legal Problems Arising From Individuals with Multiple Types of DNA“, by Robert Russell Granzen, Seton Hall Law School, 2014, was a thorough and interesting read on the matter.

Translating Christianese, Part 7

Trinity ShieldIn January & February, I posted a series of articles that (hopefully) defined some common “church talk” terms in non-jargon fashion: “sin”, “holiness”, “righteousness”, “atonement”, “grace”, “justification”, “sanctification”, “born again”, “saved”, and “repentance”. This week, I want to add to that list a distinctly Christian term, yet one you won’t find actually mentioned by that name in the Bible – the Trinity. Nevertheless, the concept is throughout the Bible, and “in the confession of the Trinity throbs the heart of the Christian religion”.[1] The Trinity is the name given to the completely unique three-in-one relationship demonstrated by God. The idea that God is one, and yet three (God the Father, God the Son, and God the Holy Spirit) is at the core of Christianity, but what exactly does that mean? Are Muslims right when they say we are polytheists worshiping three gods? Are skeptics right when they say one of our core beliefs is self-contradictory?  No. Now let’s dig into why not.

Definition

  • The Trinity, or Tri-unity, is the idea of “plurality in unity”, that God is three distinct persons united in a Being having one nature or essence: Father, Son, and Holy Spirit. The Trinity describes three “Whos” in one “What”.[2]
  • A being’s nature or essence is what it is at its core without incidentals. For example, having blond hair is not essential to a human being, but having human DNA is. Nick Vujicic, the man born without arms or legs (and pretty amazing guy), is still obviously human despite not having the limbs typical of most humans. That’s because these are not what makes us human.
  • “Personhood is traditionally understood as one who has intellect, feelings, and will.”[2] Alternatively, a person can be defined philosophically as “a self-conscious or rational being”.[3] William Lane Craig & J.P. Moreland use the concept of “imago Dei” (that humans are created in the image of God),[4] to explain that when we use terms like “person” to describe God, it’s not that we are trying to say how God is like us, but rather how we derive our nature from God. They put it this way: “Human beings do not bear God’s image in virtue of their animal bodies, which they have in common with other members of the biosphere. Rather, in being persons they uniquely reflect God’s nature. God Himself is personal, and inasmuch as we are persons we reflect Him.“[5] Part of the difficulty in understanding the Trinity is that our uniform experience is that one person correlates to exactly one human being. We have no experience with how 3 persons would correlate to 1 being.

Though there have been many attempts to explain the concept with different analogies, it’s important to remember that every analogy breaks down when the object under study is truly like nothing else. In fact, several common analogies actually explain competing ideas about God that are definitely not the Christian view. We’ll look at some of those in with related objections.

Objections

  •  Muslims look at the Trinity and think we are polytheistic (believers in multiple gods). However, the Trinity is not 3 gods (this would be tritheism), but rather one God in three divine persons. The Godhead is 3 personalities operating in perfect union, but only 1 essence.
  • Another common misconception is that God is one Being taking on different roles (or modes),  as Father, Son, and Holy Spirit at different times. This is actually an old heretical view called modalism that says that God took on different modes as our Father from eternity past, then as our Savior as Jesus, and then as the Holy Spirit  after Jesus ascended. A common illustration of the Trinity – that God is like water in that it can exist in solid (ice), liquid (water) and gas (steam) – is actually an example of modalism. While it’s still H2O in each case, it isn’t water, ice, and steam at the same time. It has to stop being one to change form to the others. Similarly, the example of how a man can be a son, a husband, and a father at the same time also falls victim to this error (the modes may be simultaneous in this case, but they are exhibited by only one person instead of three). However, each member of the Godhead is equal in being (i.e. fully God) at the same time, while differing relationally from each other.[6]
  • The law of noncontradiction explains that a statement can’t be true and false in the same sense at the same time. When skeptics claim the Trinity is a contradiction, they are forgetting the “same sense” part of that law of logic. To say that God was 1 person and 3 persons, or 1 essence and 3 essences at the same time would be a contradiction. The correct term would be that this is a paradox (a statement that appears contradictory at first, but proves not to be on closer examination), or a mystery (something we simply don’t understand fully yet, like the wave-particle duality of light).

In closing, in the Trinity, we find mystery and awe for One truly beyond our finite understanding, yet who reveals Himself sufficiently for us to grasp in small ways the scale of our Creator’s nature. We find a foundation for our own dignity as humans. Yet we also find a reason for humility in remembrance of our own limited understanding. The more we grasp this, the more we are driven to worship – to give God the honor, respect, and adoration only He deserves. I leave you with these words from theologian Wayne Grudem on the matter: “Because the existence of three persons in one God is something beyond our understanding, Christian theology has come  to use the word person to speak of these differences in relationship, not because we fully understand what is meant by the word person when referring to the Trinity, but rather so that we might say something rather than nothing.”[6]


[1] Herman Bavinck, The Doctrine of God, p. 281, as quoted in Wayne Grudem’s Systematic Theology (Zondervan, Grand Rapids, 2000), p. 247.
[2] Norm Geisler, Systematic Theology in One Volume (Bethany House, Minneapolis, 2011), p. 540-1.
[3] “Person”, www.dictionary.com, definition 5 (Philosophy), accessed 10/25/2015.
[4] Genesis 1:26-27, NASB.
[5] William Lane Craig & J.P. Moreland, Philosophical Foundations for a Christian Worldview (IVP Academic, Downer’s Grove, 2003), p.609.
[6] Wayne Grudem, Systematic Theology (Zondervan, Grand Rapids, 2000), p. 254-5.