This is a creationistic hypothesis concerning how God might have created the different species; it seeks to explain all of the relevant scientific evidence while maintaining agreement with Scripture.
A living cell's reproductive machinery can be used by a virus to produce another virus; it can also be used by a genetic engineer to produce an entirely new creature. The hypothesis which will be presented here is that God might have used His existing creatures as "surrogate mothers," expediting the creation of each new species. This hypothesis predicts some consequences - not all of which agree with naturalistic evolutionary theories.
This post will not address the question of how God might have created the first living cell. It will be assumed here that the first cell was a prokaryote or simpler. It will probably be enough to say that the possibility of intelligent design is not particularly far fetched - considering the improbability of the entire system occurring by chance. For those who would like more information about this, see Robert Shapiro's book, Origins, A Skeptic's Guide to the Creation of Life on Earth , Summit Books, N.Y., C. 1986.
When genetic engineers make changes to DNA molecules, they typically find a "surrogate mother" (usually the closest genetic candidate they can find), inject their modified DNA into a cell (often an egg cell), and let the existing cellular machinery do the work for them. The present hypothesis proposes that God might have used a similar method. God, as powerful as He might be, could, if he chose, make use of very economical methodology. It is well within His capability to simply modify the DNA in an existing egg cell and then wait, allowing His previous creations to take it from there.
More specifically, God might have taken the DNA in a female creature (female where the distinction applies) of one species and modified it to create male and female members of a new species. He may have caused the necessary atoms to align themselves using the "back door" of access He left for Himself in the design of the universe - the Heisenberg uncertainty principle.
Modifications could have been minimal. God could have left many DNA segments unmodified. In some cases there are reasons why He would have needed to do this (more detail later). As mitochondrial DNA demonstrates, He appears to have borrowed heavily from existing creatures. The pattern of mitochondrial DNA in various creatures suggests that God must have simply left it alone - not even bothering to "correct" neutral mutations which had occurred over the years.
We know from the fossil record that God created a sequence of erect-walking creatures - each step being less like an ape and more like a modern human. Even if God (having foreknowledge) would not need to make gradual "experimental" progress, there is a reason why this sequence might have been necessary anyway. If God chose to use surrogate mothers to produce the first members of each new species, he would have needed to create an entire chain of closely spaced transitional forms, connecting all species. The spacing would need to be close because a surrogate mother can't successfully deliver something too different from herself. Assuming God has chosen this method to create new species, this would not be a limitation of God's capability, it would be a limitation of the mother's.
The problem is obvious if we imagine modifying the genes in a mother mouse in such a manner that her offspring were to become a baby elephant. This is an extreme example; but the same general principle applies to even very small steps - such as the problems that humans have when there are incompatible blood RH factors between a mother and a her developing child. Since even a difference in blood type can make a true mother dangerous to her unborn baby, a "surrogate mother" (in the sense we are now considering) would need to be quite similar to any potential offspring.
If God chose to bridge major kinds using surrogate mothers, there would be an upper limit to the size of the steps which could be taken; this limit would be the point where the differences become fatal to a developing offspring. It is similar to the natural limit for interbreeding between creatures of slightly different kinds, for the same reason. If the kinds are too dissimilar, offspring cannot survive (or cannot reproduce in some cases). This hypothesis predicts that the maximum step size between created "kinds" will be at about the limit of interbreeding.
In many cases, this appears to be the approximate spacing between presently existing species. This is also approximately the spacing we find in the fossil record: we see a chain of "quantum leaps" at approximately the interbreeding limit, connecting life's kinds. This is different from the gradual continuum predicted by Darwin's theory, and different from the absence of transitional forms which most creationistic theories predict.
Darwin's theory does not predict the leaps seen in the fossil record. Its theoretical basis - random mutations and survival of the fittest - predicts that change will occur by very small steps, and that it will occur more rapidly in larger populations than in smaller ones. The leaps seen in the fossil record are sufficiently large that some scientists (most notably Gould and Eldridge) have suggested that most evolutionary change must take place quickly and in small populations, where it would not be expected to leave much evidence.
It is easy to show that the relative size of a population is a very important factor in determining whether it should evolve rapidly upwards, slowly upwards, or even downwards. If we put two targets, a large one and a small one, next to each other and randomly throw darts at them, the larger target will receive more hits. The same is true of a population of living individuals. Whatever mutation rates we assume, we can confidently expect that a larger breeding population will receive more of them than a smaller one will.
We also know that unfavorable mutations are more common than favorable ones; no one deliberately raises their family on an old nuclear test site to take advantage of possible favorable mutations. But even though favorable mutations are rare; they confer a survival advantage to offset this. How much this helps depends on the size of the breeding population which receives the mutation. If we assume that favorable mutations occur in one individual out of a thousand, and that their survival advantage will cause them to quickly spread to the whole population, a population with only ten individuals will receive a boost once in about a hundred generations. However, if the population size is a hundred individuals, a boost can be expected about every ten generations. This means smaller populations cannot evolve upward as rapidly as large ones.
This is the reason why insects and micro-organisms are able to make adaptations by which they resist man's attempts to eliminate them; they have extremely large populations. At the other extreme, the future of the California Condors is bleak; their low numbers are a liability not an asset. Without a large enough population, survival pressure simply means a high probability of extinction.
Upward evolution can be expected to occur most rapidly in large populations of individuals, but it cannot even keep pace with normal genetic deterioration (from unfavorable mutations) in very small populations. However, the fossil evidence proves that upward evolutionary change does not happen quickly in even the largest populations (such as cockroaches) where we might be expected to observe the changes over geological time. It would seem to follow that the evidence is against any naturalistic theory of evolution - although not against the creationistic hypothesis presented here..
Modern coelacanths and cockroaches (etc.) look very much like their fossil ancestors of 350 million years ago. We might expect a substantial evolutionary change in these creatures over the same time span that fish supposedly evolved through amphibian, reptile, mammal, and ape, to man; but if God really designed those animals, and if evolution is not really the creative force, then there is no reason they shouldn't have remained essentially the same for hundreds of millions of years. It is what we might expect of something which was well designed to begin with.
This hypothesis also answers some other problems with naturalistic evolution. The question is often asked, "What good is half a wing?" Possibly none, but a naturalistic evolutionist needs a beneficial reason for every step of the way. And "Why are fossils so scarce in this most fascinating region?" According to the surrogate mother hypothesis, the transitional forms may have had no immediate advantage at all; they may even have represented a liability which was intended to become a future strength. We would then expect the most interesting transitional forms to be the hardest to discover, because descendants of these misfits would have become extinct quickly, without leaving much fossil evidence.
Another question our hypothesis answers better than Darwin's theory is "Why were there so many different types of ape-men living in Africa at the same time and place?" If only the fittest can survive, why did the smaller brained, non-tool-using Australopithecines survive for more that a million years after the larger brained and tool-using Homo appeared? If that larger brain was the result of many generations worth of selective advantage, then why is the "lesser" still leaving fossils all over Africa a million years later? Under the surrogate mother hypothesis, advances in survival fitness have nothing to do with the source of new design.
Genesis 2:19 tells us that God formed the animals "out of the ground." In Genesis 2:7 we learn that man was also formed "from the dust of the ground." But, in Psalm 103:14 David reminds us that God, "knows how we are formed, he remembers that we are dust." In both Genesis 2:7 and Psalms 103:14 the Hebrew word for "dust" is "Aphar" which means dust or dry earth. The KJV also translated this word as ashes, ground, mortar, powder, and rubbish. A good general translation for this word might be the not-very-flattering English word "dirt." Notice here that it isn't just the first representatives of each living creature which are formed from dust; the rest of us are made from "dust" the same as Adam was. Adam was made from dust (Gen 2:7), returned to dust (Gen 3:19), and as we learn from the Psalms, he was dust in between; so are the rest of us.
The account in Genesis 2 describes God fashioning a male first, then using material taken from that male to create a woman. This material alone was not enough to create an entire woman. Under the surrogate mother hypothesis the critical material would have included Adam's "X" chromosomes. This could have been implanted in a surrogate mother to produce a woman. After God had created a male and female of each species, He needed to make sure they got together to reproduce. It is interesting that Gen.2:22 says this is exactly what He did.
There is also a notable parallel between the surrogate-mother methodology and the incarnation. When God brought Jesus into the world, Mary was told "The Holy Spirit will come upon you, and the power of the Highest will overshadow you; therefore, also, that Holy One who is to be born will be called the Son of God." (Luke 1:35) Whatever the Holy Spirit did, it caused a male child to be conceived. This meant the Holy Spirit must have created or modified some DNA. At the very least the male "Y" chromosome had to be engineered since Mary didn't have one. Notice that Jesus was called the "Son of God" because the Holy Spirit performed this modification. It is interesting that later in Luke (3:38), Adam is also identified as the "son of God." We don't know for sure, but we might be starting to wonder if Adam had a "surrogate" mother in the same sense Jesus did. The first Adam and the last Adam (1 Cor.15:45) might have more in common than is normally supposed.
This hypothesis is not being presented as a final word, but as a suggested possibility for others to test. Scientific falsification is invited.