Sometimes a creationist will say “there are no transitional species” or “animals do change, but one species never changes into another.” While I appreciate the sentiment, these claims are not true. In reality, new species do arise over time – a phenomenon we call speciation. Secularists sometimes claim that speciation is proof of Darwinian evolution, but this too is an error. All of these mistakes can be eliminated when we distinguish between species and kinds. Furthermore, when we study what the Bible says about kinds, and when we explore the scientific evidence pertaining to speciation, we see that the science confirms biblical creation and is inconsistent with evolution.
Species
It is always important to define key terms in rational discussions. So, what exactly is a ‘species’ and how does the term differ from a ‘kind’? The biological definition of ‘species’ is a category of classification of biological organisms ranking below genus, that involves organisms that can generally interbreed and produce fertile offspring.[1] So if we find that two animals can normally breed and produce offspring that are not sterile, then those two animals are classified as the same species.
Consider the various breeds of domestic dogs. These all belong to the same species because they can interbreed and produce fertile offspring. This does not necessarily mean that a male of any given breed can directly mate with a female of any other. Sometimes size differences would make this problematic. But through one or more intermediate breeds, the two are compatible. In other words, if dog A can breed with dog B, who can breed with C, who can breed with D (with each union producing fertile offspring), then D and A are the same species even if D and A cannot directly mate.
The offspring must also be able to reproduce if the parents are to be considered the same species. A female horse and male donkey can interbreed. But the resulting animal – the mule – is normally sterile.[2] Therefore, the horse and donkey are classified as different species. Furthermore, such interbreeding must be typical. When held in captivity, coyotes and wolves can interbreed and produce fertile offspring. However, they are classified as different species because they do not generally interbreed in the wild.
Note that there is some ambiguity in the classification of species. Species are defined as organisms that generally interbreed and produce fertile offspring. But there is no precise quantitative guideline for what ‘generally’ means. Domestic dogs and wolves do sometimes interbreed – but do they generally interbreed? It depends on who you ask. Therefore, some biologists classify domestic dogs as a different species from wolves, whereas others classify them as the same species.
Kinds
The word ‘kind’ can be used in all sorts of ways depending on context. However, when creation biologists use the word in the context of organisms, they have a very specific definition in mind. A kind is a group of organisms that are biologically related to each other – all organisms that share a common ancestor or can interbreed. All humans belong to the same kind because we are all related; we are all descendants of Adam and Eve. Conversely, we are not the same kind as gorillas, because we do not share a common ancestor. Kinds are therefore distinguished by their different ancestors which the Lord originally created. We use this definition of ‘kind’ because we believe it to be consistent with the way the Bible uses the word as we will explore below.
In Genesis 1, we find that God created organisms “after their kind” or “after its kind.” This phrase (the exact wording of which will depend on the English translation) occurs ten times in the first chapter of Genesis. It is obviously very significant. It implies that organisms (specifically plants and animals) can be grouped into categories based on certain similar properties. The Lord’s choice to create organisms according to kinds is what makes our modern taxonomic system possible.
The kind is apparently the reproductive limit of an organism. In other words, a descendant will always be the same kind as its ancestor. We infer this from Genesis 6-8 in which God brought two of each kind of air-breathing land animal aboard the ark to preserve life (Genesis 6:19; Genesis 7:2-3). The Bible specifically tells us that the purpose of taking two of each kind is so that they can produce offspring (Genesis 7:3). (Conversely, if the kind were not the reproductive limit, then it would not be necessary to take two of each kind aboard the ark.)
Genesis 1 lists a few kinds of organisms specifically. Birds are a different kind from fish which are different from cattle. These groups of organisms are biologically unrelated; they were originally supernaturally created by God, and their modern descendants do not share a common ancestor with other groups and cannot interbreed. Likewise, Adam was a special creation of God. All people today are descended from him. Humans are therefore not the same kind as any animal.
But Genesis doesn’t list, specifically, all the separate created kinds. This prompts us to ask questions like, “do lions, tigers, and domestic cats belong to the same kind, or are they descended from separate, supernaturally created ancestors?” The study of the original created kinds is called baraminology – a word derived from the Hebrew words for “created” (bara) and “kind” (min). Studies in this field have shown that lions, tigers, and house cats do in fact belong to the same kind. They are all descended from just two cats that were aboard Noah’s ark. But how do we know this?
It follows logically that two organisms can interbreed only if they are the same kind. Consider the parent organisms: A and B. They produce offspring C. Since organisms reproduce after their kind, C must be the same kind as A, and C must be the same kind as B. Therefore, A and B must be the same kind (by the transitive property). This gives us a test by which we can experimentally demonstrate whether two organisms belong to the same kind. Interbreeding studies are crucial to the field of baraminology. By such tests, we know that horses, donkeys, and mules are all part of the same kind, even though they are classified as separated species.
So, if two organisms can interbreed and produce offspring (regardless of whether the offspring are fertile), then the two organisms are the same kind. Some persons might be tempted to think that this implies that animals that cannot interbreed must be different kinds. But that is an error in reasoning.[3] Sometimes, two organisms can be the same kind and yet are not able to interbreed for one of several reasons. After all, some husbands and wives are unable to have children, but this doesn’t mean that they are not the same kind!
While we can prove that two organisms are the same kind (if they interbreed), we cannot definitively prove that two organisms are different kinds merely on the basis that they fail to interbreed. To demonstrate that two organisms are separate kinds, we need other information. We need evidence that their ancestors are not biologically related. Studies in genetics can be very helpful in such determinations. Fossil evidence can also shed light on the issue. The field of baraminology is an exciting and rapidly developing field in creation science.
Avoiding Mischaracterizations
In general, a ‘species’ is not the same thing as a ‘kind.’ We have already seen some examples of this. A horse and donkey are the same kind because they can interbreed. But they are classified as different species. Studies in baraminology have demonstrated that domestic cats and tigers belong to the same kind. Yet, they are classified as different species. The biblical teaching is that organisms reproduce organisms of the same kind but not necessarily the same species. We would expect on the basis of Scripture that all organisms today are the same kinds as their original, supernaturally-created ancestors.
We would expect, therefore, that we will not find transitional forms between the major categories of organisms – those that belong to separate kinds. Science confirms this. Cats give rise to cats and nothing else. Dogs beget dogs and nothing else. We do observe a great deal of variation within the dog kind. Many breeds exist today that did not exist when God first created dogs. But we never observe a dog reproduce anything other than a dog.
Paleontology confirms that this has always been the case. We find fossil evidence of variation within kinds of organisms as creation-based models predict. But we do not find compelling evidence of transitions between the major categories of organisms (as evolutionary models would predict) – such as a sequence of gradual transitions from invertebrates to vertebrates. Considering that the hypothetical transformation from invertebrate to vertebrate would involve a complete and revolutionary inversion of structure, presumably such a process would be lengthy and would leave behind billions of transitions. Where are they? This is indeed the case with all major categories of organisms.
Of course, there are occasional claims of a transition between some major categories. But these are nearly always disputed even by the evolutionists themselves. In most cases, additional information reveals that such disputed specimens are fully within a given kind. We have seen so many examples of this, such as archaeopteryx, Nebraska man, Coelacanth, and so on. Clearly, the fossil evidence is consistent with the creation worldview, and challenges Darwinian evolution.
Most of the “evidence” that evolutionists like to present in defense of their position involves observations of changes within a kind. You will find textbook examples of proof of evolution that involves a horse giving rise to… a horse, or a camel giving rise to a new variety of camel. But they remain the same kind. Variation within a kind is biblical.
In some cases, variations within a kind of organism lead to groups that are not able to interbreed with each other, and are therefore classified as different species. However, this is perfectly compatible with biblical creation. The evolutionist, perhaps inadvertently, mischaracterizes the creationist’s claim. “Creationists say that organisms always remain the same species, but we have observed the contrary.” No, creationists embrace speciation. But the organisms always remain the same kind.
The Taxonomic Tree
The creation scientist Carolus Linnaeus is considered the father of modern taxonomy. He recognized that God is a God of order and has created a wide variety of organisms with both similarities and differences such that they can be arranged into a logical hierarchy. With slight modification, we still use the Linnaean system today. Organisms are classified from the broadest categories down to the most specific using the following hierarchy: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
We have already seen that the biblical kind is not necessarily the same as a species. This may prompt us to ask, “what taxonomic level represents the biblical kind?” Creation biologists have found that the family level is most often aligned with the biblical kind. However, there is no reason to expect a one-to-one correspondence between the modern taxonomic system and the biblical definition of kinds since they use different criteria for classification. So, while the family level typically corresponds to the biblical kind, in some organisms, the kind is at the species or genus level. In some other cases, it may be at the order level. But the family level is typical.
One way in which critics sometimes mischaracterize the biblical position concerns the number of animals aboard Noah’s ark. The critic may claim that Noah’s ark is a silly myth because it could not possibly hold two of each species of animal. But the Bible doesn’t claim that two of each species were aboard the ark: only two of each kind of air-breathing land animal, which is a much smaller number. Since the family level more typically corresponds to the biblical kind, this is the more relevant taxonomic level by which to estimate the number of animals. Some apologists even use the genus level in order to give a generous upper limit in their estimates. One such estimate indicates a maximum of 16,000 animals aboard Noah’s ark (with the true number likely being considerably smaller). Since the ark had a volume of over 1.5 million cubic feet, space would not have been a problem.
Speciation
Since there were only two of each kind of animal on board Noah’s ark (with seven of the “clean” kinds of which there are relatively few), and since today there are often multiple species within a given kind, it follows that new species have formed since the global flood. As one example, consider the horse kind. As already discussed, horses, donkeys, and mules are all part of the horse kind, even though they are separate species. Zebras also belong to the horse kind since they can interbreed with horses. All of these animals belong to the taxonomic family Equidae. Yet, there were only two Equids aboard Noah’s ark. Modern horses, donkeys, and zebras are all descended from those two horse-kind ancestors. How then did separate species come about after the flood?
God placed a remarkable amount of potential for variety in the DNA of each kind of animal. Such variations are possible because each animal has two sets of DNA, and it is the combination of instructions on the two sets that determine an organism’s traits. Thus, animals can contain information for traits that they do not express because they do not have the right combination; but their offspring might. Placed in the DNA of the two Equids aboard Noah’s ark was the information necessary to produce zebras, donkeys, mules, and all the varieties of modern horse. These ancestral Equids probably did not look exactly like any modern equid, but had characteristics common to many of them.
As the animals departed Noah’s ark and multiplied, each descendent received only half of the genetic information from each parent, which leads to the possibility of new combinations, and hence traits that were encoded but not expressed in their parents. Under the right conditions, some of these genetic combinations can become fixed in a population such that all the population has a certain trait in common – like zebras having stripes. A different group of organisms of the same kind may inherent different genes, and the two populations begin to appear noticeably different in a process called genetic drift. In some cases, the drift can lead to reproductive incompatibility between the groups, in which case biologists will classify them as distinct species. For additional details on how this occurs, see Dr. Nathaniel Jeanson’s writings on this topic, including a helpful introductory article here, and a more detailed paper here.
The point here is that speciation has absolutely nothing to do with evolution in the Darwinian sense because the animals always remain exactly the same kind. No new information has been added to the DNA, and therefore such a process could never turn one kind of organism into another kind, since different kinds have different genetic information. Yes, we have seen the formation of new breeds of dogs – but they are still dogs. And they will never be anything but dogs. Yes, modern tigers and house cats are both descended from the same two cats aboard Noah’s ark. But they remain cats. They could never become anything else because they lack the genetic information to do so.
Scientifically, the speciation we observe in organisms is consistent with the predictions of biblical creation and not with Darwinian evolution. Speciation, genetic drift, natural selection, and mutations are all real phenomena. And they are all examples of variation within a kind. None of these processes has even been observed to produce a new kind of organism – something that is fundamentally different from its ancestor. Nor could these processes ever do such a thing even in principle. This is because none of these processes can add brand new information to the genome of any organism. But the addition of new genetic information would be essential in order for Darwinian evolution to be possible – even in principle. As always, science confirms creation.
[1] This definition pertains only to sexually reproducing organisms. Classification of asexual organisms like bacteria, though interesting, is beyond the scope of this article.
[2] In some cases, a female mule can produce offspring when mated with a horse or donkey. However, they cannot produce offspring from a male mule.
[3] It is the fallacy of the commutation of conditionals. Namely, the statement “If p then q” does not imply “if q then p.”