It’s no secret that scientists have become the most important conveyors of truth in today’s society. With our culture’s reliance upon technology to accomplish day to day tasks, it’s little wonder why scientists carry so much cultural clout in assessing the hot topics.

Unfortunately, this means that bad ideas are often given fertile room to grow unchecked and unquestioned. This is even more true on the issue of abortion, and related issues in bio-ethics. The best example would be the famous video by “Bill Nye the Science Guy”, portending to establish that “Fertilized Eggs aren’t human”, and concluding that “Women need more reproductive rights, not less.”

The video itself was garbage, but given how much of a prominent figure Bill Nye has become over the past two decades, bad arguments can be seen as a near gospel-truth.

Unfortunately, nearly every “Scientific” argument in favor of abortion relies upon a negligent research method that ignores the contributions of pro-life scientists to the question of when new human beings come into existence. Scientists such as Jerome Lejuene1, Landrum Shettles2, Ana Maria Dumitru3, Michael Buratovich4, and Maureen Condic5, have all published in-depth material addressing the questions related to the nature of early prenatal human life. The lazy stereotype of pro-life advocates being ignorant of the science of embryological development is ultimately refuted by it’s own ignorance of the material written by pro-lifers on the subject. More broadly, a recent survey of over five thousand biologists answering the question “When does a new human life begin?” resulted in 96% of biologists surveyed answering “at fertilization”6. Given that an understanding of when new human beings come into existence is crucial to the street level abortion debate for many people, both pro-life and pro-choice advocates have a vested interest in the issue.

In light of this, objections still remain. What about monozygotic twinning? If an embryo has a capacity to split into two embryos that then grow into fetal human beings and beyond, then can it really be claimed that new human individuals begin to exist at fertilization? What if two embryos, be they monozygotic or fraternal twins, fuse into one embryo, a process called human chimerism? Does this diminish the claim that new human beings come into existence at fertilization?

A new book length treatment on the issue by the above mentioned scientist Maureen Condic answers “No”. Published in February of 2020, Untangling Twinning is a vital contribution to the scientific issues related to bio-ethics issues involving prenatal life(embryo destructive research, assisted reproduction, abortion, and other topics).

Through Untangling Twinning, Dr. Condic builds a case for viewing the early embryo or zygote as a full-fledged (albeit immature) member of the human family. To summarize her argument, since sperm and egg fusion result in the creation of a new type of cell that has its own capabilities for self-directed growth, and since all the capabilities needed for growth into later human forms (ie. Fetus, newborn, toddler, and so on until adulthood) are present, it’s reasonable to conclude that new human organisms come into existence at fertilization.

In addition, Dr. Condic highlights three arguments to buttress the claim that a new organism, in particular a human organism, is present after fertilization. Writes Condic,

“First, humans, and all multicellular organisms, undergo development-that is, an orderly sequence of maturation that results in a characteristic adult form… A second characteristic of organisms is their ability to repair injury to restore the health and function of the entity as a whole. Embryos are quite remarkable in their ability to recover from even catastrophic injury…A third characteristic of organisms is adaptation to changing environmental circumstances, such that the health and overall function of the organism is preserved…Finally, at all stages of the life span, organisms show integrated function of parts to promote the health of the organism as a whole”7

Using these lines of evidence, Condic concludes “Based on this scientific description of fertilization and subsequent embryonic development, sperm-egg fusion clearly generates a new human cell, the zygote, with composition and behavior that are distinct from that of either gamete. Moreover, the zygote is not merely a unique human cell, but a cell with all the properties of a fully complete (albeit immature) human organism; it is ‘an individual constituted to carry on the activities of life by means of organs separate in function but mutually dependent: a living being.’”

This should put to rest once and for all the canard that the death of human bodily cells, such as sperm cells, egg cells, or other types of cells is the biological equivalent of the death of an embryonic human being. After all, no bodily cell has the functions or capacities listed above.

In addition, Condic addresses the incredulity some express towards the notion that a single-celled organism is a member of the human family. The answer is simple, really: We have become accustomed to dealing with humans who look “like us”, largely due to our inexperience. Agreed, it can be strange to think of ourselves as a single-celled or two-celled organism, but this is largely due to psychology on our part; it has little or nothing to do with the nature of the early embryo itself.

The stronger objection to the humanity of the embryo comes from the activity of twinning or embry fusion. As Dr. Condic notes, this poses the most significant challenge to the theory of human development beginning at fertilization, because the unitive nature of the embryo is called into question. After all, how can an entity be a unified whole, if it can end up splitting into two individuals?

Dr. Condic spends the second half of the book addressing these issues. First, regarding twinning, Dr. Condic provides a helpful explanation of the different types of twinning, and the processes that go into each part. As she argues, the act of twinning at the two-celled embryo stage doesn’t call into question the humanity of the early embryo, since all of the factors discussed above that identify the embryo remain in place. Writes Condic,

“There is clear scientific evidence that the one-cell embryo or zygote initiates a developmental trajectory; that is, the zygote is a manifestly human organism. Therefore, twinning at the two-cell stage or later does not call into question the ontological status of the original embryo as a complete and individual human being.”8

Dr. Condic asks the reader to view twinning as an asexual form of reproduction. Some organisms (such as plants) will reproduce via an asexual method (such as budding), thus resulting in a near genetically identical offspring, as opposed to sexual reproduction, which involves the union of male and female gametes from genetically distinct parents. Some have objected to this concept, stating that it’s bizarre to think of humans being reproduced through asexual means; however, Dr. Condic again points out that we are simply unaccustomed to this form of reproduction in embryos; it doesn’t call into question the identity of the new embryo.

A more bizarre challenge arises in regards to embryo fusion, where two embryos will fuse together into a single embryo, and continue development along the lifespan of a human being. The event is rare, but does occur. Dr. Condic cites the example of intersex individuals, as a possible case where male and female fraternal twins combine into a single embryo containing both male and female DNA (and the health problems associated with having both sets of genes).

Dr. Condic goes on to argue that in the case of early embryo fusion, it is most likely the case that the two individuals who existed prior to the fusion can be said to have died, as the substantial change involved in the fusion is enough to radically alter the nature of the embryo in such a way that a new entity results, even though a “corpse” is not necessary in this case to prove death.

The book goes on to provide an overview of the metaphysical issues related to early embryonic humanity, and how humanity in an ontological sense can be established. The chapter provides a summarized version of the argument Dr. Condic made with her brother in their previous book Human Embryos, Human Beings. In addition, Dr. Condic provides a short chapter addressing the issues that currently cause many scientists to doubt the humanity of the early embryo, and suggests possible changes to the practice of embryo research to more ethically study the smallest and youngest human beings among us.

Untangling Twinning will serve as one of the most vital contributions to the pro-life cause, by helping pro-lifers understand the scientific issues related to human embryos and to buttress their arguments for treating embryonic human beings as members of the human family. In addition, the book will also provide a challenge to those on the opposite side of the aisle to come up with a more sophisticated understanding of embryonic human beings.


1Lejuene, Jerome, The Concentration Can: When Does Human Life Begin? An Eminent Geneticist Testifies, Ignatius Press, April 1992

2Shettles, Landrum B. Rites of Life: The Scientific Evidence for Life Before Birth Zondervan, December 1983

3Dumitru, Ana Maria, “Science, Embryonic Autonomy, and the Question of When Life Begins”, The Public 4Discourse, January 24, 2017

4Buratovich, Michael, The Stem Cell Epistles, Wipf and Stock, August 2013

5Condic, Samuel and Condic, Maureen, Human Embryos, Human Beings, Catholic University of America Press, May 2018

6Jacobs, Steven “Biologists Consensus on ‘When Life Begins’”, University of Chicago, Aug 06, 2018 https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3211703

7Condic, pg. 10, emphasis in original

8Condic, pg. 48 Emphasis in original