Is a cloned embryo a human person?

Psychiatrist Paul McHugh has argued that embryos made by means of somatic cell transfer (SCNT) are not human persons even though those made by fertilization are. According to McHugh, SCNT is a “biological manufacturing process” that is used to make, not babies, but embryonic stem cell lines, and “resembles tissue culture” more than fertilization. McHugh has even fashioned the name “clonotes” for SCNT-derived embryos to distinguish them from embryo made by fertilization with sperm.

What is the substantive difference between embryos made by fertilization and those made by SCNT? McHugh’s main argument is as follows:

…If one used the notion of “potential” to protect cells developed through SCNT because with further manipulation they might become a living clone, then every somatic cell would deserve some protection because it has the potential to follow the same path (Paul R. McHugh, “Zygote and ‘Clonote’ – The Ethical Use of Embryonic Stem Cells,” New England Journal of Medicine 351 (2004): 209-11).

In other words, because nuclei from almost any somatic cell can be used to form a clonote, almost any somatic cell has the potential to become a clonote. It is absurd to regard all the somatic cells of our bodies as human persons. As Robert Lanza of Advanced Cell Technologies stated, “research advances are making all cells embryonic, but if you consider these cells human life, then 100 souls are lost every time I sneeze” (Joannie Fischer, “The First Clone,” U.S. News and World Report (3 December, 2001). Since it is untenable to regard somatic cells, which have the ability to form clonotes, as human persons, it is equally untenable to regard clonotes as human persons.

McHugh’s second argument notes that the vast majority of clonotes are grossly abnormal and die very early during development. Thus clonotes are not human persons, which make the production of ESCs from them morally justifiable.

McHugh’s second point is overstated. While many cloned animals develop into animals with a variety of developmental abnormalities, not all of then do. To classify cloned animals as a distinct kind of creature because they possess abnormalities ignores those cloned animals that either do not possess such abnormalities or whose health overlaps with animals that were not made by the process of cloning. If the abnormalities are part of the reason for assigning cloned animals into a different category, then that classification fails for normal cloned animals.

Secondly, molecular comparisons of cloned embryos with embryos made from in vitro fertilization have revealed extensive similarities. The abnormalities only arise later, once the embryo implants into the uterus. Thus the abnormalities that McHugh uses to disqualify cloned embryos as human persons have yet to arise.

Thirdly, if cloned embryos differ in kind from embryos made by fertilization, then what of those cloned animals that survived to term: Are such animals a different kind of animal? Consider Dolly, the cloned sheep. Was she so different as to not be considered a Suffolk Blackface sheep? This seems patently absurd. If relegating the cloned adult to a lower status is fallacious, then it is just as fallacious to demote cloned embryos to a similar status.

Finally, even if cloned embryos have abnormalities, so what? Do we really want to dismiss the humanity of an individual because they carry some sort of handicap? Dismissing the humanity of cloned embryos because of their potential abnormalities is tantamount to dismissing abnormal children and allowing medical research on them since their death is immanent (Robert P. George and Christopher Tollefson, Embryo: A Defense of Human Life (New York: Doubleday, 2008): 184-9). We should find such a proposal revolting.

What of McHugh’s first point; that is, nuclei from any somatic cell can produce a cloned embryo, and therefore, all somatic cells are potential embryos and deserve protection, which is absurd? On this point, the analogy of somatic cells with embryos seems hopelessly flawed. In fact, the entire category of “potential embryos” is simply nonsensical (Robert P. George and Patrick Lee, “Acorns and Embryos,” The New Atlantis (Fall 2004/Winter 2005): 90-100). The term embryo refers to a very specific entity in the life of an organism. Something is either an embryo or not. Secondly, somatic cells are not similar to embryos. Instead they are similar to sperm and eggs, the cells that are used to make embryos. Once the sperm and the egg fuse and complete conception, they no longer exist. Instead a new entity, the embryo, which did not exist before hand, begins it existence. The embryo is a “distinct, complete, self-integrating organism.” Somatic cells are no such thing, but are, instead, part of an organism. SCNT or fertilization makes an embryo. Thus McHugh’s first point also fails.


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Professor of Biochemistry at Spring Arbor University (SAU) in Spring Arbor, MI. Have been at SAU since 1999. Author of The Stem Cell Epistles. Before that I was a postdoctoral research fellow at the University of Pennsylvania in Philadelphia, PA (1997-1999), and Sussex University, Falmer, UK (1994-1997). I studied Cell and Developmental Biology at UC Irvine (PhD 1994), and Microbiology at UC Davis (MA 1986, BS 1984).

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