|Feature Article - October 2011|
|by Do-While Jones|
Does speciation lead to macroevolution?
In a nutshell, the theory of evolution depends upon the notion that many small variations can accumulate over many generations to the point that new organs, new biological systems, and even new kinds of living things arise through the process of natural selection. When a group of individuals become sufficiently different from their ancestors, they are classified as a new species. When this happens, “speciation” is said to occur.
Evolutionists have extended this notion to the origin of the higher biological categories of genera, families, orders, classes, phyla, and kingdoms. So, we need to ponder whether or not speciation occurs, and, if it does, if the extrapolation to higher taxonomic categories is justified.
The first obvious question is, “Does speciation actually occur?” In order to answer this question we need to know how to differentiate species from each other. In a few cases, this is surprisingly difficult to do.
The common criterion is reproductive viability. If two individuals can mate to produce fertile offspring, then they are considered to be the same species. The reproductive test seems clear enough for sexual plants and animals, and works in almost every case. Unfortunately, it doesn’t work in every case.
Mathematicians will be quick to assert that if A=B and B=C then A=C. It is a fundamental transitive law of logic. So, if individual A is the same species as individual B, and individual B is the same species as individual C, then individuals A and C should be the same species and should be able to create fertile offspring. Unfortunately, biologists have discovered a few rare cases where individuals of population B can mate with individuals of populations A and C, but individuals of populations A and C cannot mate with each other. Are the members of populations A and C the same species or not? Expert opinions vary. If we can’t even agree whether or not they are different species, it makes it impossible to say if speciation has actually occurred or not.
To make matters worse, there is no way at all to use a sexual reproductive test on things (like bacteria) that don’t reproduce sexually.
Many years ago I happened to be at a conference and struck up a conversation with a biologist who worked with bacteria. I asked him how they tell the species of bacteria apart. He said they use chemical tests. They introduce some chemical agent into the culture and see how the bacteria respond. Do they change color? Do they die? Do they produce some chemical in response to an allergic reaction?
Some people respond differently to various chemicals, such as those in bee venom and peanuts. Certainly people who are allergic to bees or peanuts aren’t a different species of humans, so the chemical response criterion isn’t a perfect, universal test.
There is legitimate concern that overuse of antibiotics will kill off all the weaker bacteria and allow “super bugs” to flourish. This is supposedly proof of evolution. As important an issue as bacterial resistance to antibiotics is, it really has nothing to do with evolution as it relates to the origin of new kinds of life. If we were to inject every living person with bee venom, it would kill off all the people allergic to bees, leaving a population resistant to bee stings. That new population would not be a new species, and it would not be an example of human evolution. Similarly, bacterial resistance to antibiotics is not a true example of evolution.
It was years ago when the biologist told me they use chemical tests to distinguish between species. They no doubt now use DNA testing to look for differences, as well. But how different does the DNA have to be for two things to be considered to be different species? Who makes that decision?
Chihuahuas and Great Danes are two very different breeds of dogs, but universally agreed to be of the same species. How different is their DNA? And, exactly how does one calculate the difference in DNA? Different ways of calculating similarity can lead to very different results.
Crows and Ravens are both big, black birds. It is hard to tell them apart. The primary difference is the shape of their tails when they fly. They are much more alike than Chihuahuas and Great Danes. Why should they be considered separate species?
It is sometimes difficult to tell species apart, and the criteria for telling species apart are somewhat subjective, and don’t always work. Since it can be really difficult to tell species apart (in some cases), it is difficult to decide if speciation has actually occurred. Are these individuals (or populations) different species or merely different breeds of the same species?
Creationists generally agree that different breeds can arise through artificial selection. We know where the various pedigreed breeds of dogs and thoroughbred horses came from because there is historical documentation. So, regardless of whether or not new breeds are actually new species, there is agreement between creationists and evolutionists that selective breeding can create a population of individuals with distinctive characteristics.
Now, just to get past the rather sticky problem of the definition of species, let’s just imagine that all breeds of dogs, horses, and varieties of hybrid corn and roses are actually new species. Let’s go down that road and see where it takes us.
If all the different breeds of dogs were actually different species, how would that affect the biological classification system? All these new species would still be dogs. How different would a new species of dog have to be to be moved out of the Canis (dog) genus and be the only member of an entirely new genus?
Scientists have never observed the offspring of one species to be so different that it deserved to be in a different genus. Speciation doesn’t create new genera—it merely creates a new division in an existing genus. Speciation doesn’t explain the origin of genera, families, orders, classes, phyla, or kingdoms.
As difficult as it is to define a species, it gets even more difficult to define what constitutes a genus, family, order, class, phylum, or kingdom. These higher biological categories are just arbitrary divisions originally invented by Linnaeus to facilitate study, but have lately been assumed to be evidence of biological descent.
Similar species are grouped into a genus. Similar genera are grouped into a family. Similar families are grouped into an order, et cetera. Evolutionists assume that the similarity is due to descent from a close common ancestor; but there is no real evidence to support that assumption.
Occasionally biologists rearrange (or create new) categories. That doesn’t mean evolution has occurred. It just means a change has occurred on a piece of paper.
Two months ago we mentioned that some vegetarians are included in the meat-eating order Carnivora 1 just because they seem to belong there. The rational that they belong together is because they presumably share a common ancestor. In other words, the modern biological classification system is based entirely on the assumption of evolution, and therefore cannot logically be considered to be evidence for evolution.
Linnaeus originally divided vertebrates from invertebrates simply because it is useful to compare and contrast animals having central nervous systems with animals that don’t. His arbitrary division does not prove that an unknown species of invertebrate evolved a central nervous system by accident, and that all vertebrates descended from it.
The biological classification system is simply evidence of man’s ability to organize things. It isn’t evidence of evolution.
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Disclosure, August 2011, “The Mole’s Thumb”