Christians and non-Christians alike often question whether the theory of evolution is accurate. Those who express doubts about the theory are often labeled “unscientific” or “backwards” by some in the pro-evolution camp. At times, the popular perception of evolution seems to be that it has been proven beyond all doubt and there are no scientific obstacles left for it. In reality, there are quite a few scientific flaws in the theory that provide reasons to be skeptical. Granted, none of these questions necessarily disproves evolution, but they do show how the theory is less than settled.
There are many ways in which evolution can be criticized scientifically, but most of those criticisms are highly specific. There are countless examples of genetic characteristics, ecological systems, evolutionary trees, enzyme properties, and other facts that are very difficult to square with the theory of evolution. Detailed descriptions of these can be highly technical and are beyond the scope of a summary such as this. Generally speaking, it’s accurate to say that science has yet to provide consistent answers to how evolution operates at the molecular, genetic, or even ecological levels in a consistent and supportable way.
Other flaws in the theory of evolution can be separated into three basic areas. First, there is the contradiction between “punctuated equilibrium” and “gradualism.” Second is the problem in projecting “microevolution” into “macroevolution.” Third is the unfortunate way in which the theory has been unscientifically abused for philosophical reasons.
First, there is a contradiction between “punctuated equilibrium” and “gradualism.” There are two basic possibilities for how naturalistic evolution can occur. This flaw in the theory of evolution occurs because these two ideas are mutually exclusive, and yet there is evidence suggestive of both of them. Gradualism implies that organisms experience a relatively steady rate of mutations, resulting in a somewhat “smooth” transition from early forms to later ones. This was the original assumption derived from the theory of evolution. Punctuated equilibrium, on the other hand, implies that mutation rates are heavily influenced by a unique set of coincidences. Therefore, organisms will experience long periods of stability, “punctuated” by short bursts of rapid evolution.
Gradualism seems to be contradicted by the fossil record. Organisms appear suddenly and demonstrate little change over long periods. The fossil record has been greatly expanded over the last century, and the more fossils that are found, the more gradualism seems to be disproved. It was this overt refutation of gradualism in the fossil record that prompted the theory of punctuated equilibrium.
The fossil record might seem to support punctuated equilibrium, but again, there are major problems. The basic assumption of punctuated equilibrium is that a very few creatures, all from the same large population, will experience several beneficial mutations, all at the same time. Right away, one can see how improbable this is. Then, those few members separate completely from the main population so that their new genes can be passed to the next generation (another unlikely event). Given the wide diversity of life, this kind of amazing coincidence would have to happen all the time.
While the improbable nature of punctuated equilibrium speaks for itself, scientific studies have also cast doubt on the benefits it would confer. Separating a few members from a larger population results in inbreeding. This results in decreased reproductive ability, harmful genetic abnormalities, and so forth. In essence, the events that should be promoting “survival of the fittest” cripple the organisms instead.
Despite what some claim, punctuated equilibrium is not a more refined version of gradualism. They have very different assumptions about the mechanisms behind evolution and the way those mechanisms behave. Neither is a satisfactory explanation for how life came to be as diverse and balanced as it is, and yet there are no other reasonable options for how evolution can operate.
The second flaw is the problem of extending “microevolution” into “macroevolution.” Laboratory studies have shown that organisms are capable of adaptation. That is, living things have an ability to shift their biology to better fit their environment. However, those same studies have demonstrated that such changes can only go so far, and those organisms have not fundamentally changed. These small changes are called “microevolution.” Microevolution can result in some drastic changes, such as those found in dogs. All dogs are the same species, and one can see how much variation there is. But even the most aggressive breeding has never turned a dog into something else. There is a limit to how large, small, smart, or hairy a dog can become through breeding. Experimentally, there is no reason to suggest that a species can change beyond its own genetic limits and become something else.
Long-term evolution, though, requires “macroevolution,” which refers to those large-scale changes. Microevolution turns a wolf into a Chihuahua or a Great Dane. Macroevolution would turn a fish into a cow or a duck. There is a massive difference in scale and effect between microevolution and macroevolution. This flaw in the theory of evolution is that experimentation does not support the ability of many small changes to transform one species into another.
Finally, there is the flawed application of evolution. This is not a flaw in the scientific theory, of course, but an error in the way the theory has been abused for non-scientific purposes. There are still many, many questions about biological life that evolution has not answered. And yet, there are those who try to transform the theory from a biological explanation into a metaphysical one. Every time a person claims that the theory of evolution disproves religion, spirituality, or God, they are taking the theory outside of its own limits. Fairly or not, the theory of evolution has been hijacked as an anti-religious mascot by those with an axe to grind against God.
Overall, there are many solidly scientific reasons to question the theory of evolution. These flaws may be resolved by science, or they may eventually kill the theory all together. We don’t know which one will happen, but we do know this: the theory of evolution is far from settled, and rational people can question it scientifically.