The liberal blogosphere is apparently up in arms over recent remarks by straight-shooter Senator Marco Rubio on the Sean Hannity Show and subsequently reported in the Huffington Post, exposing the science denialism that occurs on the political left.
“Here’s what I always get a kick out of, and it shows you the hypocrisy. All these people always wag their finger at me about science and settled science. Let me give you a bit of settled science that they’ll never admit to,” Rubio said. “The science is settled, it’s not even a consensus, it is a unanimity, that human life beings at conception. So I hope the next time someone wags their finger about science, they’ll ask one of these leaders on the left: ‘Do you agree with the consensus of scientists that say that human life begins at conception?’ I’d like to see someone ask that question.” (Remark made on on the Sean Hannity Show, May 14, 2014)
Senator Marco Rubio is absolutely correct when he states: “The science is settled, it’s not even a consensus, it is a unanimity, that human life beings at conception.” Just to be perfectly clear: what begins at conception is the life of an individual human being, not “life” in general, as opposed to inanimate matter. The meaning of Senator Rubio’s statement should be obvious to anyone who isn’t being intentionally obtuse. The following three quotes by acknowledged experts in the field demonstrate the scientific unanimity that exists on this question.
The unanimous verdict of science: conception marks the beginning of a new human individual
Dr. Micheline Matthew-Roth, a principal research associate at Harvard Medical School’s Department of Medicine has stated:
“It is scientifically correct to say that an individual human life begins at conception, when egg and sperm join to form the zygote, and this developing human always is a member of our species in all stages of life.” [The Human Life Bill – S. 158, Report together with Additional and Minority Views to the Committee on the Judiciary, United States Senate, made by its Subcommittee on Separation of Powers, 97th Congress, 1st Session (1981) see Francis J. Beckwith, Politically Correct Death: Answering the Arguments for Abortion Rights (Grand Rapids, MI: Baker Books, 1993), p. 43] (Emphasis mine – VJT.)
The French geneticist Jerome L. LeJeune (1926-1994), who was the co-discoverer of trisomy 21 (which causes Down syndrome) has stated:
“To accept the fact that after fertilization has taken place a new human has come into being is no longer a matter of taste or opinion. The human nature of the human being from conception to old age is not a metaphysical contention, it is plain experimental evidence.” [The Human Life Bill: Hearings on S. 158 Before the Subcommittee on Separation of Powers of the Senate Judiciary Committee, 97th Congress, 1st Session (1981). See Norman L. Geisler, Christian Ethics: Options and Issues (Grand Rapids, MI: Baker Books, 1989), p. 149 also Francis J. Beckwith, Politically Correct Death: Answering the Arguments for Abortion Rights (Grand Rapids, MI: Baker Books, 1993), p. 42.] (Emphases mine – VJT.)
And finally, Dr. Hymie Gordon, professor of medical genetics and Mayo Clinic physician has stated:
“I think we can now also say that the question of the beginning of life – when life begins – is no longer a question for theological or philosophical dispute. It is an established scientific fact. Theologians and philosophers may go on to debate the meaning of life or purpose of life, but it is an established fact that all life, including human life, begins at the moment of conception.” [The Human Life Bill – S. 158, Report 9, see Francis J. Beckwith, Politically Correct Death: Answering the Arguments for Abortion Rights (Grand Rapids, MI: Baker Books, 1993), p. 42.] (Emphases mine – VJT.)
Professor Myers accuses Senator Rubio of being scientifically misinformed
Game, set and match? Evolutionary biologist PZ Myers thinks not. In a recent post titled, Marco Rubio is already Gish-galloping (May 17, 2014), Professor Myers writes:
What do you mean by “life begins”? Was there some step between your parents and you where there was a dead cell? Life is continuous — there hasn’t been a transition from non-life to life for about 4 billion years. So, yes, I’d agree that the zygote is a living cell, but so were the sperm and egg that fused to generate it, and so were the blast cells that were precursors to it, and so were the zygotes that developed into your parents. We can trace that life all the way back to early progenotes with limited autonomy drifting in Archean seas, to self-perpetuating chemical reactions occurring in porous rocks in the deep ocean rifts. It’s all been alive, so this is a distinction without meaning. (Emphases mine – VJT.)
In the foregoing passage, Professor Myers is attacking a “straw man.” No-one is disputing that we can trace “life” back to its earliest beginnings long ago, and no-one is claiming that zygotes develop from inanimate matter. The claim being made by Senator Rubio, which is accepted by all competent embryologists, is that conception marks the beginning of a new human being, from that which was not a human being (sperm and ovum).
Professor Myers continues:
What about “human”? It’s a human zygote, we’d all agree; but it’s also human sperm and human ovum. You can pluck a hair from my head and determine with a few tests that it’s a human hair; you can take a blood sample from me and check a few antigens and determine that it is human blood; you can similarly swab a bit of saliva or earwax or tears from me, and analyze its biochemistry and find that it is specifically human spit or earwax or tears. That we can tag something with the adjective “human” does not in any way imply that my earwax deserves all the protections and privileges of a full human being. “Human zygote” imposes as much ethical obligation on me as “human spit”. (Emphases mine – VJT.)
Here’s a simple question for Professor Myers: can you find me a single embryologist who refers to “human spit” as “an individual human life,” as Dr. Micheline Matthew-Roth of Harvard Medical School did when referring to the human zygote? There’s a very good reason embryologists don’t do that. A one-cell embryo is totipotent: the switches in its genes are fully activated, enabling it to divide and produce all of the differentiated cells in an organism. Later on, as cells in the embryo specialize, various genes in each cell are switched off or silenced. That is why “human spit” will never develop into anything, and why it has absolutely no chance of becoming a baby.
Finally, Professor Myers addresses the real point that Senator Rubio was making, but even here, he resorts to a smokescreen and caricatures the position that he is opposing:
And don’t even try to pull that BS about a unique, novel genetic individual being created at conception. One of the key properties of meiosis is a genetic reshuffling of alleles by random assortment of the parental chromosomes and recombination by crossing over — every sperm and egg is genetically unique as well, and we spew those profligately with no remorse. Conception just adds another level of semi-random rearrangement of a random assortment of genes that were made during oogenesis and spermatogenesis. (Emphases mine – VJT.)
First, genetic uniqueness has absolutely nothing to do with the point that Senator Rubio was making on the Sean Hannity show. A human clone would not be genetically unique, as its DNA would be identical to that of its human parent, but it would unquestionably be a distinct individual human being. And a deleterious, cancer-causing mutation in a human body cell would make that cell genetically unique – but I’m quite sure Senator Rubio would not call that cell a new human individual. Genetic uniqueness, then, is neither a necessary nor a sufficient condition for being a distinct human individual. Everyone, be they pro-life or pro-choice, agrees on that point.
Second, neither a human sperm cell nor a human ovum constitutes a human organism. Embryologists agree that fertilization normally marks the beginning of the human being as an individual organism, and that the sperm and oocyte (unfertilized egg, in popular parlance) which exist prior to that point are human cells, but not human organisms. The following selection of statements from embryology textbooks establish this point:
“Human development begins at fertilization, the process during which a male gamete or sperm … unites with a female gamete or oocyte … to form a single cell [embryo]. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual. (p. 18) … The usual site of fertilization is the ampulla of the uterine tube [fallopian tube], its longest and widest part. If the oocyte is not fertilized here, it slowly passes along the tube to the uterus, where it degenerates and is resorbed. Although fertilization may occur in other parts of the tube, it does not occur in the uterus. … The embryo’s chromosomes sex is determined at fertilization by the kind of sperm (X or Y) that fertilizes the ovum; hence it is the father rather than the mother whose gamete determines the sex of the embryo.” [Keith Moore and T.V.N. Persaud, The Developing Human: Clinically Oriented Embryology (6th ed. only) (Philadelphia: W.B. Saunders Company, 1998), p. 37].
“Human pregnancy begins with the fusion of an egg and a sperm. (p. 3); … finally, the fertilized egg, now properly called an embryo, must make its way into the uterus (p. 3); … The sex of the future embryo is determined by the chromosomal complement of the spermatozoon … Through the mingling of maternal and paternal chromosomes, the [embryo] is a genetically unique product of chromosomal reassortment …” [Bruce M. Carlson, Human Embryology and Developmental Biology (St. Louis, MO: Mosby, 1994 ), p. 31; ibid, Carlson 1999, pp., 2, 23, 27, 32].
“In this text, we begin our description of the developing human with the formation and differentiation of the male and female sex cells or gametes, which will unite at fertilization to initiate the embryonic development of a new individual. … Fertilization takes place in the oviduct [not the uterus]… resulting in the formation of an [embryo] containing a single diploid nucleus. Embryonic development is considered to begin at this point…” (p. 1). [William J. Larsen, Human Embryology (New York: Churchill Livingstone, 1997), p. 17].
O’Rahilly 2001 – Table 8-1
“Principal Features of Developmental States of the early human embryo: Stage 1 – Includes penetrated oocyte, ootid, and zygote. Thus accordingly, the penetrated oocyte and the ootid (before syngamy) are characterized as an already existing human embryo at Stage 1 of development.” [Ronan O’Rahilly and Fabiola Muller, Human Embryology & Teratology (New York: Wiley-Liss, 2001), p. 89]. (Emphases mine – VJT.)
Scientia locuta est, causa finita est. Embryologists agree: fertilization marks the beginning of a new human individual. Could the verdict of science possibly be any clearer? PZ Myers’ case lies in tatters.
Amanda Marcotte enters the fray
Feminist blogger Amanda Marcotte endorsed Professor Myers’ criticisms of Senator Rubio, in a recent article titled, How Right-Wingers Are Amping Up Their War on Science and Reality (May 20, 2014). To be fair to Ms. Marcotte, however, she did also raise some substantive philosophical points of her own, and her article therefore merits more serious consideration than Professor Myers’ hastily written post.
(a) Amanda Marcotte channels PZ Myers on the meaning of “life”
Ms. Marcotte’s attempted rebuttal of Senator Rubio does not begin well. She writes:
The claim that “human life” begins at conception is not one asserted by science, but by religion, as many religions believe that’s when God injects a soul into a human body. But science is pretty clear that, by the scientific and not religious definition of “life,” life does not begin with conception. In order for life to begin, it has to be non-life turning into life. Since both the sperm and egg are alive, by the measure of science, it’s not life beginning. It’s really just life continuing.
As biologist P.Z. Myers explains, “We can trace that life all the way back to early progenotes with limited autonomy drifting in Archean seas, to self-perpetuating chemical reactions occurring in porous rocks in the deep ocean rifts. It’s all been alive, so this is a distinction without meaning.”
I have to say that Ms. Marcotte is being obtuse here. As I pointed out above, the claim being made is that conception marks the beginning of an individual human being, not the beginning of “life” (which originated long before human beings appeared on Earth). Also, the claim that conception marks the beginning of a new human being is completely distinct from the question of whether human beings have a soul, created by God. Senator Rubio is not claiming that science can answer the latter question. Ms. Marcotte is deliberately muddying the waters here, by bringing religion into the discussion.
A philosophical aside: The case for the personhood of the zygote, in a nutshell
If Ms. Marcotte would like to know how we can reason from the premise, “This zygote is an individual human being” to the conclusion, “This zygote is a human person,” then I’d be happy to set her straight. Let me begin by asking her a hypothetical question: suppose (purely for argument’s sake) that a human zygote were capable of developing into a rational adult human being all by itself, without any external assistance whatsoever. I think Ms. Marcotte would agree that if the zygote had such a fantastic ability, it would surely deserve to be called a human person. Why? Because anything that can make itself into a human person, without any help, is morally equivalent to a human person: we might say that it already “virtually contains” all of the attributes of human persons. But anything that’s morally equivalent to a person, is a person: for instance, if we agree that human persons have certain rights, and that zygotes are morally equivalent to human persons, it follows that zygotes must have the same rights.
I should point out, however, that in real life, human persons never do accomplish anything without external assistance – a point which Ms. Marcotte should appreciate, as she would presumably endorse President Barack Obama’s election campaign phrase, “You didn’t build that“. Independence is not the hallmark of a human person; it is a trait that we might associate with a free-living bacterium. To be human is to be dependent on others. Why, then, should we demand that anything that can make itself into a person should be capable of doing the job unassisted, before we recognize it as morally equivalent to a human person?
Now I’d like to ask Ms. Marcotte a second question: would she consider a human zygote to be a human person, merely on the grounds that it had the potential to develop into one? I’m quite sure she would answer “No” to this question – and I would completely agree with her. Normally, a potential X is not morally equivalent to an actual X: to cite an illustration from philosopher Peter Singer’s Practical Ethics, “Prince Charles is (at the time of writing) a potential King of England, but he does not now have the rights of a king” (Cambridge University Press, 3rd edition, 2011, p. 138). A sperm cell, an ovum and even the food that we eat can all be said (in a sense) to have the potential to develop into a human person, since the matter in each of these things will eventually be transformed into matter that makes up part of the body of a human person.
To be sure, pro-lifers could point out that a human zygote undergoes the transformation into a rational adult, without loss of identity, whereas a sperm cell and an ovum (or more precisely, an oocyte) lose their identity when they fuse to become a one-cell embryo. But a clever pro-choice advocate could reply: what kind of identity are we talking about here? Biological identity or personal identity? It still needs to be demonstrated that the former is sufficient for the latter.
Now, here’s a third question for Ms. Marcotte: would she consider a human zygote to be a human being, if it contained its own internal program, which controlled and directed its development into a human person, when placed in a hospitable environment? That is, would she agree with the premise, “Anything which controls its own development into a person, is morally equivalent to a person”? That is the vital premise appealed to by people who regard the embryo/fetus as a human person. Ms. Marcotte will notice that this premise says nothing about immaterial souls, or what have you. The premise is also intuitively plausible, and it clearly excludes sperm cells and ova as candidates for personhood, as these cells do not control their own development into anything. At the same time, it includes the human zygote as a suitable candidate for being a person. Maureen Condic, Associate Professor of Neurobiology and Anatomy at the University of Utah School of Medicine, explains why a one-cell embryo can be said to have its own developmental program, in an online paper titled, When Does Human Life Begin? A Scientific Perspective (White Paper, Volume 1, Number 1, October 2008, published by The Westchester Institute for Ethics and the Human Person):
A car is not a car until it rolls off the assembly line – until then it is a bunch of parts in the process of becoming a car, but not there yet. Similarly, a cake is not a cake until it comes out of the oven – until then it is a variously gooey mass of flour, sugar, eggs, and butter that is gradually becoming a cake. (p. 11)
However, a profound difference exists between manufacturing and embryonic development. The difference is who (or what) is doing the “producing.” The embryo is not something that is being passively built by the process of development, with some unspecified, external “builder” controlling the assembly of embryonic components. Rather, the embryo is manufacturing itself. The organized pattern of development doesn’t produce the embryo; it is produced by the embryo as a consequence of the zygote’s internal, self-organizing power. Indeed, this “totipotency,” or the power of the zygote both to generate all the cells of the body and simultaneously to organize those cells into coherent, interacting bodily structures, is the defining feature of the embryo. (p. 11)
From the moment of sperm-egg fusion, a human zygote acts as a complete whole, with all the parts of the zygote interacting in an orchestrated fashion to generate the structures and relationships required for the zygote to continue developing towards its mature state. … Everything the zygote does from the point of sperm-egg fusion onward is uniquely ordered to prevent further binding of sperm and to promote the preservation and development of the zygote itself. The zygote acts immediately and decisively to initiate a program of development that will, if uninterrupted by accident, disease, or external intervention, proceed seamlessly through formation of the definitive body, birth, childhood, adolescence, maturity, and aging, ending with death. This coordinated behavior is the very hallmark of an organism. (p. 7)
Now, I realize that some skeptical readers may be inclined to doubt the legitimacy of the word “program” in a biological context. Perhaps, they may object, the term is merely a poetic metaphor. Not so. It’s a scientifically respectable term, and it has a well-defined meaning. If the reader goes to PubMed and types “genetic program” in the subject field in quotes, over 1,000 citations will appear. Typing “developmental program” will bring up over 1,400 citations.
And for those who are still skeptical, let them consider the following quote, from a distinguished biologist:
“The body plan of an animal, and hence its exact mode of development, is a property of its species and is thus encoded in the genome. Embryonic development is an enormous informational transaction, in which DNA sequence data generate and guide the system-wide spatial deployment of specific cellular functions.” (Emerging properties of animal gene regulatory networks by Eric H. Davidson. Nature 468, issue 7326 [16 December 2010]: 911-920. doi:10.1038/nature09645. Davidson is a Professor of Cell Biology at the California Institute of Technology.)
Finally, a sophisticated pro-choice advocate might concede that a human zygote controls its own biological development into a baby, but nevertheless maintain that in order to become a person, it is wholly dependent on the adult care-givers (especially parents, grandparents and teachers) with whom it interacts: it is these people who teach a baby how to talk, and impart to it the gift of language, without which it would be unable to have a concept of self, which is an essential condition for having rights. This process of social development, or “personalization,” the pro-choice proponent might maintain, is controlled not from within, but from outside. We do not make ourselves into persons; other people do that.
The fallacy of the foregoing line of argument should be obvious enough: where did the first human persons in history acquire their personhood from? The standard rejoinder (much loved by Darwinists) that there is no clear-cut boundary between “persons” and “non-persons” in Nature only serves to obfuscate the key point: that if “personhood” is something acquired from outside, then its first appearance, whether instantaneous or gradual, is inexplicable, in principle.
In any case, the pro-choice advocate’s assertion that our acquisition of language (and of a concept of self) is controlled not from within, but from outside, deserves to be challenged. For it is the human brain which processes the jumble of sounds that babies eventually come to recognize as language, and makes sense of it. And it is the human brain which processes the information that a child is exposed to, when he/she goes to school. It follows, then, that if a human being’s built-in developmental program directs the development of his/her brain, then that individual’s acquisition of language and of a self-concept is ultimately controlled from within, and not from without.
To sum up: the personhood of the human zygote can be cogently argued for without appealing to religious or metaphysical premises.
(b) Ms. Marcotte misconstrues the uniqueness of the human zygote
But Amanda Marcotte hasn’t finished making her argument yet. She continues:
Nor does science agree that “conception” makes a distinct human person, as opposed to simply a cell that, like the sperm and egg that made it, has a unique combination of DNA. As Myers notes, “Conception just adds another level of semi-random rearrangement of a random assortment of genes that were made during oogenesis and spermatogenesis.”
Ms. Marcotte is also guilty of setting up a false dichotomy in her foregoing remark: either the human zygote is a distinct human person in its own right, or its distinctness merely amounts to having “a unique combination of DNA.” She fails to consider a third, intermediate possibility, which science can establish: namely, that the human zygote is a distinct human organism (unlike a sperm cell, an ovum, and the skin cells we shed every day). Since it is a human organism which is distinct from other organisms, it can accurately be described as a new human being.
Ms. Marcotte is also guilty of setting up a straw man, in her polemic directed at Senator Rubio. Not once in his interview with Sean Hannity on May 14, 2014, did Senator Rubio state that a human zygote is a human person. Nor did he claim that science had shown it to be a human person. “Person” is a legal term; it is not the province of science to determine when “personhood” begins. What science does tell us is that conception marks the beginning of a new human individual. “Human individual” is a biological term, and science can tell us about what qualifies as a human individual, and what doesn’t. And in the case of the human zygote, the verdict of science is clear.
In any case, the personhood of the zygote can be defended by appealing to highly plausible, common-sensical ethical premises, which make no mention of either religion or metaphysics, as I argued above.
(c) Ms. Marcotte invokes the tired old “twinning argument”
Finally, Ms. Marcotte delivers what she considers to be her coup de grace:
Indeed, sometimes a zygote splits into two separately developing individuals after conception, ones that have the same DNA but will be born as two separate people. We know them as “identical twins.” If “science” believed that “life” begins at conception, then science would argue identical twins are the same person. Science clearly does not believe that identical twins are one person because they have the same DNA.
As I remarked above, having a unique set of DNA is neither a necessary nor a sufficient condition for being a unique human individual. What happens to the zygote subsequent to conception has no logical connection with the question of what it already is at the moment of conception.
Incidentally, the term “moment of conception” is a scientifically accurate one, since conception is an event which takes only one second to occur, as Associate Professor Maureen Condic points out in her online paper, When Does Human Life Begin? A Scientific Perspective (White Paper Volume 1, Number 1, October 2008, published by The Westchester Institute for Ethics and the Human Person):
The basic events of early development are both reasonably well characterized and entirely uncontested. Following the binding of sperm and egg to each other, the membranes of these two cells fuse, creating in this instant a single hybrid cell: the zygote or one-cell embryo… Cell fusion is a well studied and very rapid event, occurring in less than a second. Because the zygote arises from the fusion of two different cells, it contains all the components of both sperm and egg, and therefore the zygote has a unique molecular composition that is distinct from either gamete.
Subsequent to sperm-egg fusion, events rapidly occur in the zygote that do not normally occur in either sperm or egg. The contents of what was previously the sperm, including its nucleus, enter the cytoplasm of the newly formed zygote. Within minutes of membrane fusion, the zygote initiates changes in its ionic composition that will, over the next 30 minutes, result in chemical modifications of the zona pellucida, an acellular structure surrounding the zygote… These modifications block sperm binding to the cell surface and prevent further intrusion of additional spermatozoa on the unfolding process of development. Thus, the zygote acts immediately and specifically to antagonize the function of the gametes from which it is derived; while the “goal” of both sperm and egg is to find each other and to fuse, the first act of the zygote is immediately to prevent any further binding of sperm to the cell surface. Clearly, then, the prior trajectories of sperm and egg have been abandoned, and a new developmental trajectory—that of the zygote—has taken their place. (p. 3) (Emphases mine – VJT.)
The “twinning argument” answered
And now, what about the “twinning argument” put forward by Ms. Marcotte? My reply to this argument is: so what if embryos can twin? All that means is that humans have two modes of reproduction – sexual and asexual – and that the parents of identical twins are really their grand-parents (their parent – the embryo from which they both developed – having died). What’s the metaphysical problem here? There isn’t one. Nature has killed the parent embryo, but sadly, Nature kills children all the time: as Buffon, the French naturalist, observed in the 18th century: “One third of the human race perishes before reaching the age of 28 months. Half the human race perishes before the age of eight years.” (See Death and the Social Order by Michael Kearl, of Trinity College.)
I’d now like to quote from an essay entitled, The Metaphysical Status of the Embryo: Some Arguments Revisited by Professor David Oderberg (in Journal of Applied Philosophy 25 (2008): 263-76):
More importantly, though, there is no good argument for the metaphysical conclusion that an embryo is not an individual human either because it might or must twin. The mere fact that it might twin makes the case no different from that of the lightning strike. An embryo cannot be considered to lack individuality because something might happen to it. Many plants are capable of being split into objects that are themselves plants and capable of continuing to grow as plants. Planarian flatworms can be divided and the divided halves continue to grow as individual worms. Cells that can divide are no less individual cells because of that possibility — they belong to exactly the same kind as their descendants. This includes cellular animals such as bacteria and amoebae. Why, then, should human zygotes or early embryos be an exception?
Moreover, amoebae and most bacteria always reproduce by division, and yet they still all belong to the same kind — but we know that only a small minority of human embryos ever divide. So why should individuality be withheld from the latter whilst accorded to the former? We can be certain, moreover, that the reproduction by fission of amoebae and bacteria is determined rather than the result of a massive conjunction of chance events: it is part of their constitution. By parity of reasoning, therefore, even if humans always came into existence as twin descendants of embryos, and even if this were determined, the embryos would not thereby fail for human individuality. (pp. 268-269) (Emphases mine – VJT.)
I conclude that the attempts by the liberal left to counter Senator Rubio’s claim that scientists in the field are unanimous that a new human being comes into existence at conception are utterly devoid of merit. The recent “attack pieces” by PZ Myers and Amanda Marcotte serve as an excellent illustration of the fact that the liberal left has “science denial” problems of its own.
Finally, readers who are interested are welcome to peruse my online book, Embryo and Einstein – Why They’re Equal.