Let’s Think About a Zygote Like an Engineer
Having read Evolution News for years, contributing an occasional article or two, in addition to my 81-part series on “The Designed Body,” I’ve noticed that there’s a certain way we proponents of intelligent design tend to frame our arguments. We usually provide information on what it takes for life to work, rather than just how it looks (per much of neo-Darwinism). Then we look for reasonable explanations of causation which must include where the information came from to properly produce, assemble, and coordinate all the necessary parts of a given system that we know is absolutely needed for survival (most of that is absent from neo-Darwinism).
But in my collaboration with Steve Laufmann to produce our book Your Designed Body, we came to the conclusion that a different style may be more useful. What we propose is that, in addition to what’s described above, we also engage readers with examples of “problem-solving” just like engineers do it. After all, it takes one to know one. If you’ve never used mental energy to try to solve any one of these hard problems of life, then how can you appreciate what it took to come up with and apply the solution?
Let’s try the following as an exercise. Once you’ve gone through it, you’ll be better prepared to understand all the causal hurdles that had to have been surmounted. And this will allow you to ask better questions and not be as vulnerable to many of the “just so” stories of neo-Darwinism.
“Separation of Concerns”
Recently, there was an article in The Scientist, “The First Two Cells in a Human Embryo Contribute Disproportionately to Fetal Development.” It noted a study published in Cell, “The first two blastomeres contribute unequally to the human embryo,” indicating that “a research team showed that, contrary to current models, one early embryonic cell dominates lineages that will become the fetus.”
The gist of the article was that the current thinking — that it’s at the eight-cell stage where totipotent embryonic cells take the first “fork in the road” of commitment to developing into the fetus or the placenta — may be incorrect. It would now seem that this first “separation of concerns” (as Laufmann and I call it) may take place earlier on, when the zygote divides into the first two blastomeres.
Ingenious methods were used to label and track the cell lineage from the two-cell to the blastocyst stage:“Thus, they could determine the contribution of each cell to the development of two early structures: the trophectoderm (TE) that becomes the placenta and the inner cell mass (ICM) that eventually produces the fetal tissue.”
“They are not identical,” explains Magdalena Zernicka-Goetz, a developmental and stem cell biologist at Caltech and the University of Cambridge who is a study co-author. “Only one of the two cells is truly totipotent, meaning it can give rise to body and placenta, and the second cell gives rise mainly to placenta.” She adds, “I was always interested in how cells decide their fate.” The article in The Scientist concludes by telling us that “next, Zernicka-Goetz aims to investigate the features and origins of the differences between clones at the two-cell stage.”
Points to Ponder
It is clear that scientists still do not fully understand how human life develops from the zygote to a newborn and then into a mature fertile adult. One has to wonder what signaling and communication must take place at exactly the right times and in the right orders for all of this to happen properly, never mind where the information and instructions came from. Despite this self-acknowledged lack of understanding, we are told by evolutionary science that it certainly was an unguided and undirected natural process that brought it into being, and not a mind at work, as intelligent design contends.
What do you think? If you took your car to a mechanic and he told you that he has no idea what’s wrong with it but he’s sure he can fix it, would you engage his services? Just because the scientist is smarter than you about what parts do what and how, that doesn’t necessarily mean that her conclusions about causation are true. After all, in saying that “I was always interested in how cells decide their fate,” she’s attributing agency, a mind at work, to the zygote. So don’t be misled.
Human Life Is a Hard Problem
Actually, life is a series of millions of hard problems that have to be solved all the time, or else. I’m talking about, among many other things, the cellular, metabolic, anatomical, and neuromuscular problems of human life. Let’s start from square one — the human zygote — how each of us began after the sperm of our father joined with the egg of our mother within her womb. That is the one cell from which, within nine months, we developed into a three-trillion-cell newborn with all the equipment we needed to survive.
If you could go back in time to that moment in your life, be nanosized and micro-pipetted into your own first cell, what would be the first problem you’d have to solve? In other words, once the zygote comes into being, what’s the first thing it has to do?
Well, if it’s going to become a newborn in nine months or so, it’s got to start dividing. But that won’t happen for at least 24 hours, so you have to consider what else may be more important as the zygote floats within the fluid of your mom’s uterus.
The chemical content of the fluid inside the zygote (high potassium, low sodium) is the opposite of what’s in the fluid surrounding it (low potassium, high sodium). And because these ions can cross the cell membrane, diffusion would naturally make them try to equalize on both sides (inside and outside the zygote) which would spell disaster. So, the sodium/potassium pumps in the zygote’s cell membrane have to kick in right away to keep pushing sodium out and bringing potassium back in, right?
Yes, the action of the million or so sodium/potassium pumps in the zygote’s cell membrane are needed for it to stay alive. But what do they need to do their work?
All work requires energy. So, as with all of life, the first priority of the zygote is to generate enough energy through glycolysis (without oxygen) and cellular respiration (with oxygen). The zygote needs oxygen and glucose (or other substances) to metabolize to get the energy it needs.
And if the zygote’s going to divide into two cells, then four, eight, sixteen, and more, then it’s also going to need nutrients to be able to make more copies of itself. Where does the new human life get the oxygen and nutrients it needs, and how does it make sure of its supply until it becomes a newborn?
The Engineering Problem
This is how Steve Laufmann and I framed this engineering problem in our book:
All cells need oxygen and nutrients. Early life is no exception. Fertilization results in a zygote, which multiplies through cell division to become an embryo. In the early phase, the embryo gets what is needed by diffusion from the surrounding fluid. This works when there’s only a few dozen cells. But within several weeks the embryo will grow into a fetus, and in a few months into a newborn with trillions of specialized cells organized into coherent, interdependent, finely tuned organ systems. For this to be possible, the embryo needs a better way to get oxygen and nutrients, and to get rid of carbon dioxide and waste materials. If he cannot meet this challenge, he will not survive. But he’s in a special situation, dwelling inside his mother, so he’ll need a solution altogether different from anything else in the body’s inventory — a distinct yet temporary system that can meet this need while he’s developing his permanent internal systems.
We go on to ask a very important engineering question:
How do you build a series of finely tuned, coherent interdependent systems, each necessary for life, and stay alive the whole time? It just wouldn’t do if the body needed to go dead for a while, build some stuff, then come back to life when everything was ready to go. What the child in the womb needs is a complete set of temporary systems to meet the needs of his rapidly growing body, to keep it alive until its own systems are ready to take over. Then at birth, when they are no longer needed, these systems must be discarded as the child transitions to long-term systems.
The Solution Is the Placenta
The answer to the very hard engineering problem we asked above is the placenta. Somehow or other the zygote has the foresight to know that down the road it will develop into a fetus that requires the placenta for its metabolic and nutritional needs.
This is how we explain the solution in our book:
Tissues of the embryo (TE) combine with tissues of the mother (lining of the uterus) to make the placenta — a totally separate organ that provides the scaffolding needed to keep the developing child alive. The placenta enables the mother to sustain the developing child while his internal organ systems and tissues are being fabricated, integrated, and launched. The developing child is, quite literally, on life support between the zygote phase and birth, when his body is finally ready to take over the job.
Up until this recent study it was thought that it’s not until the embryo consists of at least eight cells that some of them start to commit to being part of the placenta (TE). But now it seems that it takes place at the two-cell stage. If your nanosized self is inside the zygote, which lever do you pull to make sure that one of the two forming blastomeres goes down the TE-track? And even more important, where did the lever come from?
It appears that, based on the findings of this study, the answer to the first question will be the concern of future research. But since, as we are regularly assured, we all know that life came about from the unguided and undirected processes of natural selection acting on random variation, the second question is assumed to have already been answered back in 1859, before we knew any of these intricate particulars and when biological systems were assumed to be vastly simpler than they turned out to be. What do you think? Any questions?
