The Claim

With statements like, “The questioning of Darwinism was a bridge too far for many,” Ben Stein wants viewers of Expelled to believe that scientists subscribe to an unquestioned Darwinian orthodoxy, and that those who dare to question “Darwinism” will quickly be silenced.

The Facts

No one denies it is difficult to get a new scientific idea accepted, but that isn’t the same as claiming that the doors of science are slammed shut to those who challenge the status quo. When scientists question facets of existing theories or propose new ones, they present the best evidence available and make the strongest arguments they can to their colleagues. Colleagues in turn challenge that evidence and reasoning. The rigor of this process is what makes science such a powerful tool. Because scientists have to fight hard to get their ideas accepted, good ideas win out – when they are proven to be sound. Intelligent design advocates, in contrast, have no research and no evidence, and have repeatedly shown themselves unwilling to formulate testable hypotheses; yet they complain about an imagined exclusion, even after having flunked the basics.

The scientific enterprise is open to new ideas, however much they initially may be challenged. Here are some examples of people who have challenged the scientific status quo and, far from being “expelled” from science, were lauded as visionaries – once they had successfully proven their ideas.

Barbara McClintock

Barbara McClintock's microscope and maize at the American Museum of Natural HistoryBarbara McClintock’s research on maize in the 1940s and 1950s showed that sequences of DNA called transposons can change positions within a chromosome, and in doing so, can regulate the expression of other genes. This discovery went against the accepted view that DNA was merely a static set of instructions, and the initial response to her research was so skeptical that, after several years of developing her ideas, she stopped publishing about them out of concern that she would alienate the scientific mainstream.

Unlike intelligent design proponents, however, she did not claim discrimination and attempt to circumvent the peer review process. Rather, she continued to research the evolution and genetics of maize. As new technology developed, other scientists verified her discoveries. McClintock was the recipient of many awards, including the National Medal of Science, the first MacArthur Foundation grant, and the Nobel Prize for Physiology or Medicine.

Lynn Margulis

Lynn Margulis, taken by Javier Pedreira. Licensed under the Creative Commons Attribution ShareAlike 2.5Lynn Margulis wrote a paper, “The Origin of Mitosing Eukaryotic Cells,” which argued that eukaryotic cells – those with a true nucleus – arose when cells with no nucleus symbiotically incorporated other such cells to make new cells that could perform more functions. The paper was rejected by many journals, and when eventually published by The Journal of Theoretical Biology it was highly criticized. Margulis spent decades defending her work, but scientists now accept her suggested mechanism through which organelles such as mitochondria and chloroplasts evolved. Her suggestions about other organelles have not stood up to experimental tests, and are not as widely accepted.

Margulis strongly opposes the idea, widely held within the scientific community, that the driving force in evolution is competition, and thinks cooperative and symbiotic relationships are underemphasized by many evolutionary scientists. Despite holding views different from many in the scientific community, because of her research, she is well respected, and has been elected to the National Academy of Sciences and awarded the National Medal of Science.

Barry Marshall

Prior to Barry Marshall’s discovery that peptic ulcers are caused by the bacteria Helicobacter pylori, the accepted explanation was that they were the result of stress, diet, and an excess of acid in the stomach. When Marshall presented his research, it was greeted with skepticism, and it took many years for his theories to become widely accepted. Although Marshall suggested that a conspiracy prevented acceptance of his work (in his case, pharmaceutical companies which stood to lose money on ulcer treatments), he did not respond by withdrawing from the scientific process, but by continuing to run experiments that would allow others to replicate his findings. Because he did so, scientists were able to evaluate his work and conduct their own experiments to test his proposals. Whether or not there was a pharmaceutical company conspiracy, scientists were willing to pursue Marshall’s idea and to publish results that supported it. In time, the community of science came to accept his results.. Marshall received many awards, including the Nobel Prize in Physiology or Medicine, and was made a Companion of the Order of Australia.

As Marshall himself observed, “Although people were skeptical, and they all went home with the aim of trying to prove me wrong, that’s how science moves forward. Someone has a hypothesis and you say, ‘Okay, if I can prove it wrong, I can publish a paper saying he’s wrong.’ Gradually, over the next few years, one by one, these people trying to prove me wrong fell by the wayside and actually converted over to my side.”

In contrast, scientists who have responded to the claims of intelligent design proponents have all found that evidence for ID claims was lacking and that ID advocates’ hypotheses – in the rare situations where they offered them – did not stand up to scrutiny.

Stanley Prusiner

Stanley PrusinerIn 1982, Stanley Prusiner published an article on his research into scrapie – a disease in sheep related to Creutzfeldt-Jakob disease – which argued that the infectious agent was not a virus but a protein, which Prusiner called a “prion”. Because no one had heard of a protein replicating without a nucleic acid like DNA or RNA, many virologists and scrapie researchers reacted to the article with incredulity. When the media picked up the story, “the personal attacks of the naysayers at times became very vicious,” according to Prusiner. However, his critics failed to find the nucleic acid they were sure existed, and less than two years later, Prusiner’s lab had isolated the protein. Subsequent research provided even more support for prions, and in 1997 Prusiner was awarded the Nobel Prize in Physiology or Medicine. The Nobel Prize Committee explained:

The hypothesis that prions are able to replicate without a genome and to cause disease violated all conventional conceptions and during the 1980s was severely criticised. For more than 10 years, Stanley Prusiner fought an uneven battle against overwhelming opposition. Research during the 1990s has, however, rendered strong support for the correctness of Prusiner’s prion hypothesis. The mystery behind scrapie, kuru, and mad cow disease has finally been unravelled. Additionally, the discovery of prions has opened up new avenues to better understand the pathogenesis of other more common dementias, such as Alzheimer’s disease.

Lambs; presence of scrapie unknown. Photo by Wikimedia user Robek

Motoo Kimura

In 1967, Motoo Kimura published a paper showing that the genetic content of the genome must have been influenced substantially by selectively neutral genetic drift. Other authors built on this work to argue that molecular evolution might be dominated by neutral drift, and not by natural selection. As William Provine writes, “The initial reaction to the neutral theory of Kimura, King and Jukes was generally very negative” (”The Neutral Theory of Molecular Evolution, Random Drift and Natural Selection.” In Cain A.J. and Provine W.B. “Genes and ecology in history.” Reprinted in Berry R.J. et al (eds) 1991. Genes in ecology: the 33rd Symposium of the British Ecological Society. Blackwell, Oxford, p. 23-25). Provine adds, “when DNA sequence data began to pour in after the early 1980s, the situation changed dramatically.” The abundance of selectively neutral differences within populations and among species matched the predictions of the neutral theory, and could not be explained by selection alone.

“By 1990,” Provine continues, “molecular evolutionists had largely abandoned the null hypothesis of selection to explain observed molecular differences and accepted the neutral theory…. Even the molecular evolutionists who argue for the importance of selection at the DNA level construct and use models for which the neutral theory is the assumption.” This represented a radical change in the scientific approach to evolution, which had formerly considered natural selection to be paramount. Clearly, evolution at the molecular level operated by different rules. Although the neutralist hypothesis was a break with traditional neodarwinism, its incorporation into evolutionary biology was smooth — once researchers had the ability to gather DNA sequence data and test the predictions of the theory.

So the scientific consensus can be and is challenged regularly. There is no unchallengeable orthodoxy, which is what Expelled would have you believe. The preceding stories are just a few well-known examples of biologists who challenged the scientific consensus, including principles of Mendelian genetics and of Darwinian evolution. These scientists prevailed because they did good science: they backed their challenges with successful predictions and empirical evidence. And, they were right. Scientists are constantly questioning, refining, and expanding theories, including evolution – and natural selection theory. As Michael Shermer writes, “Anyone who thinks that scientists do not question Darwinism has never been to an evolutionary conference.”

There is no reason why intelligent design proponents cannot follow in the footsteps of these distinguished scientists who overcame sometimes considerable opposition, sometimes for a very long time, before their scientific views prevailed. Unlike ID advocates, these researchers didn’t skip past the research phase to try to influence the public before they had scientific support. None of them formed groups to lobby school boards to teach their views in the public schools; they just buckled down and did the work. None of them drafted model legislation or penned op-eds in newspapers and magazines decrying the supposed persecution they suffered at the hands of The Establishment; they just buckled down and did the work. None of them hired former Nixon speechwriters or game-show hosts to compare their opponents to Hitler; they just buckled down and did the work.

The difference between what scientists do and what intelligent design proponents do is that when scientists question aspects of evolution they do it with science, while intelligent design proponents do it with dishonest movies, tired slogans, and slick marketing.