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...
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.
What are some flaws in the theory of evolution? | GotQuestions.org