Devoluton and an Evolutionary “Ladder”
When I first began reading Creationist arguments, I ran across the claim that humans as well as all other species were deteriorating. — One well known Creation Scientist I read claimed that the first humans lived for several hundreds of years and were therefore superior to all humans alive today. And based on that reasoning, he claimed that we were “devolving,” not evolving — devolving since the time of Noah’s flood. My reading of Creationist and Intelligent Design lit is that for evolution to be true, everything has to lead to an improvement.
Joseph Mastropaolo, a Creation “scientist,” for example, talks about medical disabilities and harmful mutations saying that this argues against evolutionary theory. He says that if evolution were true, then there should be less mutations less disease.
From the medical literature, the evidence suggesting evolution is zero and the evidence suggesting the exact opposite, devolution, is more than 15,400. Obviously, evolution is the exact opposite of reality.
Just as a side note, Mastropaolo’s insistence that evolutionary theory makes the prediction that there should be less disease fails to take into account that the viruses and bacteria that are responsible for sickness and disabilities evolve as well, so the persistance of disease is perfectly consistent with evolution. — Also, he says,
If evolution is true, then we should observe a decrease in human mutations, medically designated human genetic disorders, over time according to one definition of evolution, change over time, and another definition, natural selection. [ . . . ] The actual data show that genetic disorders doubled every 13 years through the sixties, seventies and eighties. In the nineties, genetic disorders doubled in about half the time, every seven years.
How ’bout that? I guess for evolution to be true, harmful mutations and genetic defects should become less frequent as time goes on. This is quite an over-simplistic understanding of how evolution works. — I think I’m being too generous by even describing his description of the process as an “understanding” because that’s not how evolution works at all. It doesn’t ensure against more disabilities in the future, and it certainly never claimed to guarantee that the occurence of detrimental mutations would be reduced in the future.
Such claims and insinuations are common in Creationists literature. Their perception is that there is a certain requirement that there there is a dictated direction from the simple to the complex, and that anything that seemingly goes in the opposite “direction” is a refutation of evolutionary theory. — The idea of “devolution” is based on the common misconception that evolution is directionary, that is, that increasing complexity is a necessary outcome for evolutionary change. The truth is that evolution doesn’t dictate any such trend. It has no pre-ordained direction.
The idea of a “ladder” of progression was proposed by several, but notably by the French naturalist Jean Baptist de Lamarck who believed that the simplest life forms were on the bottom while the most complex forms (i.e., humans) were on the top. Charles Darwin, however, did not subscribe to Lamark’s ideas, considering them unreliable. In fact, by the time Darwin had appeared on the scene, the idea of a chain was losing it’s support, but Darwin was the one that ultimately demolished it. — He envisioned a tree with the branches dividing, and so on, though modern evolutionary theory is shown as more of a “bush.”
Rather than just adding, evolution often reduces as well. Tapeworms lose their guts, cavefish lose their eyes, and humans lose their appendix. The ancestors of these particular species had fully functioning versions of these particular organs, though the modern counterparts are either semi-functional or non functional. There is no reason why apparently “simple” creatures cannot have evolved from more complex ancestors, and there is reason why this would happen: If you don’t use it, you tend to lose it.
The claim that devolution occurs rather than evolution shows that Creationists either do not understand evolution, or they feel the need to redefine it so they can make it look like a pseudo-scientific absurdity. The reality is that ‘devolution’ is not a legitimate biological term. So far, I haven’t been able to find it in any science textbook. The only people who use the term tend to be just laypeople or Creationists.
As a final observation, talk about “devolution” and an evolutionary “ladder” actually causes a fundamental contradiction of another common Creationist fallacy: The claim that Darwinian Evolution is based on pure chance. If evolutionary theory dictates that organisms absolutely have to become more complex, then how could evolution be based on pure coincidence? Logically, you cannot accept both ideas. Though to be honest, Evolution isn’t based on pure chance: Though mutations are random occurences, Natural Selection is the exact opposite of chance.
The fact of the matter is, the concept of an “Evolutionary ladder” is an oxymoron. It has no place in modern biology, so if you hear anyone using such a term, you can be sure that person doesn’t understand evolutionary theory.
Age of the Earth, Medical Science, Adam, Eve, Even, and the Flood, by Joseph Mastropaolo
Jean Baptist de Lamarck
The Reluctant Mr. Darwin: An Intimate Portrate of Charles Darwin and the Making of His Theory of Evolution, page 74. By David Quammen.
Getting the Monkey off Darwin’s Back: Four Common Myths About Evolution, by Charles Sullivan and Cameron Mcpherson Smith. From the Committee for Skeptical Inquiry
Evolution myths: Natural selection leads to ever greater complexity by Michael Le Page. From New Scientist.
Evolution Theory Overview, from FossilMuseum.Net