Dr. John Ankerberg: Dr. Menton, how do genes actually function in the body?

Dr. David Menton: In evolution we’re interested in not just how you get a new protein, we’re interested in how you get eyes and ears and giraffes and lions and tigers, things like that. Of course that’s a very profound question.

I think all of us a certain scientific faith that genes have something to do with ears and eyes and liver. But genes really code for a protein classically, and in its most simple sense we can say one gene codes for one protein, although it gets more complicated than that. Or genes can turn on and off other genes so they can have some dynamically control of other genes.

Not all genes are available to be expressed; after all, all of the cells of our body contain all of the genes necessary to presumably make another copy of us. One living cell in our skin contains all of the genes to make another us. But we can’t have all of those genes expressed, otherwise, we would have a little embryo developing or trying to develop in our skin and all we really want to do in the skin is make a skin cell. We want it to fill up with a tough filamentous protein called keratin, which is a very complex protein; in fact it is a whole family of proteins. And we want that cell to die at just the right time and produce a dead stratum corneum. And if we don’t produce that dead stratum corneum, which is about as thick as Mylar film, we would die in a matter of hours by massive water loss, we would go into shock and die.

So the skin is differentiating to death. We don’t often think of a functional cell in our body actually becoming functional only when it dies, we think of living cells. But in the case of the skin, those epidermal cells differentiate to death, form the dead layer in the top and that’s critically important to our survival. But all of the other genes need to be turned off. We must only leave the genes on that will give us a proper skin cell which would involve several of the genes. But we don’t want genes that are going to make an eye or what have you.

The interesting thing is I don’t think we really have a lot of information on how we produce a complex organ. We know how we make a protein. We’ll take the most abundant protein in nature, the most abundant protein is collagen. Now many people can understand collagen by looking at a leather wallet. Leather is dermis. It is the deep layer of the skin—not the epidermis, the superficial that makes keratin—it’s the deep layer. They usually don’t include the epidermis on leather. And this is made up a tough fibrous material and many proteins indeed are fibrous or filamentous. And this is one of the most complex proteins in nature.

Now just because we have a gene now that can assemble collagen and this has been very carefully studied, and there are many collagens, not just one, now we have collagen. But is that going to make an ear? There is collagen in the ear. Collagen is really the connective tissue of the body. It has been called the excelsior of life. It’s the stuff in which many of the other cells work. So is that going to produce an ear, is that going to produce an eye?

I think we all have a certain faith that yes, genes somehow do tell us how to not only make a fibrous protein called collagen, but now we have to take this protein and we have to weave it. It’s sort of like a weaver, who has filamentous thread and now wants to weave a garment, or the fabric for a garment first, and then finally when you get the fabric, to fashion this fabric into an organ.

Now we call the fabric itself tissue, and there are many different tissues in the body and when you take the tissues or the cloth and you produce a garment, we call the garment an organ. So starting out with collagen, yes, we can have a gene or perhaps several genes, that are going to code for a filamentous protein, the most abundant in nature called collagen. So now you have it. You have a lot of thread.

But now you have to weave the thread and make a fabric. And you can’t just weave it any which way, you know. Take skin and you pull on it, and it makes a little tent fold. And if you leave go, it collapses. (They say you can determine your age by how quickly it snaps down. If it snaps down quickly, you are a very young fellow. And if it just sort of sits there and collapses very slowly, then you’re older.)

We know that the biomechanics of skin—that is, the elasticity of skin—is, among other things, related to the way the collagen, this protein, is woven as a fabric or as a tissue. The collagen itself does not stretch very much, I mean everything stretches a little, but if you had a filament of collagen and a filament of steel and they were both the same diameter, the collagen would be less elastic than the steel.

Now think of this. Our skin, just to pick one thing, the deep layer, the dermis of the skin, the bulk of the thickness, i.e., the leather, that is a woven tissue in its simplest sense, of collagen fibers which themselves are not very elastic at all, that is less elastic than steel. But because of the way it is woven, something perhaps rather like a double-knit suit, in fact, it stretches a little differently in one axis than in another. If you cut a round hole in the skin you don’t leave a round wound, you get a slit-like wound that stretches out because it’s under tension differently one way than another, so like fabric it has a warp and woof.

This woven material needs to be woven in a very precise way to produce the normal mechanical properties of skin or in the case of a blood vessel, say an artery, the normal mechanical qualities of this artery are determined in large part by the way collagen, a connective tissue, is woven in the wall of the artery and its different in a vein and of course, muscle enters in there too.

Who tells the collagen fibers (to use an anthropomorphism), who tells the collagen fibers that, okay, we want a layer of fibers running this way, and then we want a layer running this way and a layer this way and a layer this way. That would be a very simple plot like in a tire. Collagen fibers in bone sometimes run in this way, looking rather like a radial-ply tire.

The cornea, which is this little window over our eye that’s really made out of skin, very highly modified skin, the dermal component of that cornea, that would be comparable to the dermis of our skin, is beautifully transparent. You can look through it. And you can look through it because the collagen fibers are arranged in a very precise orthogonal way; that is, they are perpendicular to one another. They are a very special kind of collagen, different than the collagen in the skin and they are hydrated with water to produce this marvelous clarity. If you disturb the fiber architecture of the cornea, if you disturb its state of hydration, the cornea becomes milky and you don’t see. The cornea in fact is more important for focusing, or as a lens, than the lens itself is. It bends the light more than the lens does. The lens is just very low in its control on focusing.

So, I think the important question here for the evolutionist to consider (and I guess the creationist too) is, are we really even ready to talk about how we produce skin, or liver, or kidneys? We’re really at a level of understanding in the molecular biologies still really focusing more on trying to understanding how you produce a protein. But how do we now go from the protein to an ear, or many different proteins? I think that’s the big question.