|Barred spiral galaxy NGC1672 [Courtesy NASA]|
Other writers claim that scientists have conspired to keep from the public eye some important evidence undermining evolution (or other theories in the science-religion arena), or, at the least, that there is some "group-think" phenomenon going on, wherein scientists are reluctant to publish material that would draw these established theories into question. As a single example, the 2008 movie "Expelled" claimed that creationist and intelligent design writers have been systematically shut out from scientific journals and conferences, due to a "conspiracy" among the scientific establishment. In a similar vein, Philip Skell, a retired chemistry professor at Pennsylvania State University recently wrote that an unquestioning acceptance of Darwinism has persisted in the field of biology "mainly because too many scientists were afraid to challenge what had become a philosophical orthodoxy among their colleagues" [Skell2005].
How do scientists respond to these claims? Are the basic notions of old-earth geology, evolution and big bang cosmology really considered "controversial" among scientists? Is there a "conspiracy" to hide the "truth"?
For similar reasons, evolution, at this point in time, is much more than a "theory" in the colloquial sense of the word. The basic notion of evolution, namely that life began on Earth more than three billion years ago and has been evolving and elaborating since then, has been confirmed in hundreds of thousands of exacting studies, even as some of the actual branching and mechanisms continue to be investigated. Indeed, the latest DNA sequence data screams "common descent" -- there is no other reasonable way to interpret these results (see DNA and Evolution for additional details).
Also, the basic notion that the universe we reside in began approximately in an explosive burst 13.8 billion years ago and has been expanding and evolving since then, with matter coalescing into stars and galaxies over the eons, leading to an environment conducive for biological development on Earth, is hardly in doubt, even as the actual details and mechanisms of exactly how this happens continue to be investigated -- see Big bang.
Finally, claims that large numbers of scientists question the basics of evolution or cosmology are simply false. For example, more than 99% of all qualified professional scientists in these fields agree with the fundamental precepts of evolution -- see Scientists-evolution.
Here are just a few examples of the many true controversies that could be mentioned, some of them quite heated:
One of the best examples of public scientific controversy arose from the 2004 discovery of Homo floresiensis, more commonly known as the "hobbit" due to its diminutive size, on the island of Flores in the Indian Ocean north of Australia. Remarkably, this specimen lived until as recently as 66,000 years ago [Brown2004; Wade2004]. The discoverers pointed out that the fossil combined an unusual mix of human and early hominid features, including a nearly complete skull that most resembled Homo erectus, but with legs more akin to Australopithecines. The authors theorized that the specimen represented a distinct species of hominins, and its diminutive size was due to an effect known as "island dwarfism" (the evolutionary reduction in size of a species confined to an island or other domain with limited resources).
A heated and rather public controversy ensued [Krause2009]. The initial salvo was from biologists Maciej Hennenberg and Alan Thorne, who dismissed the notion of a separate species, saying that the small skull instead represented merely a case of microcephaly, a malady that causes dwarfism in afflicted humans. In response, Brown and Morwood acerbically described Henneberg and Thorne's article as "an extremely poorly informed, and ill designed, piece of 'research'." The microcephaly explanation was then boosted by a paper published by Indonesian researcher Teuku Jacob in the prestigious National Academy of Science, after a detailed comparison of the hobbit bones with the skeletal features of regional humans. What's more, Robert Martin of the Field Museum of Natural History in Chicago published a paper drawing into question the initial claim that the Hobbits had descended from Homo erectus. But then Dean Falk, a leading expert on hominid brain evolution at Florida State University, found that although the Flores find was most similar to that of Homo erectus and was least similar, among the various candidates, to microcephalic humans.
Subsequently additional hobbit skeletons were found, casting more doubt on the microcephaly alternative explanation. Critics of the new species designation have asserted that there are numerous other pathologies that need to be examined. For example, a 2010 study noted similarities between anatomical features of the Flores specimens and persons afflicted with hypothyroid cretinism (iodine deficiency). Numerous other studies have been done, with researchers aligning on one side of the debate or the other [Oxnard2010; Callaway2009; NS2010; Kaplan2011; Pacchioli2014].
In November 2015, Japanese researchers found, after a thorough analysis of hobbit teeth, that the specimens had numerous dental traits not typical of any human (or any other known hominin), but relatively close to those of Homo erectus [Choi2015]. This was followed in April 2016 by a team led by Canadian paleoanthropologist Matthew Tocheri, who found, by carefully dating ash in the cave and the hobbit fossils themselves, that the hobbits lived from 66,000 to 87,000 years ago, not 18,000 as originally claimed, which rules out the possibility that these are human (since humans did not arrive on the island until 50,000 years ago) [Gramling2016]. In June 2016, Australian researchers announced the discovery of additional Homo floresiensis fossils, some as old as 700,000 years [Zimmer2016a]. Finally, in April 2017, in the most comprehensive study to date, researchers concluded that the hobbits were a distinct hominin lineage, most likely not likely descended from Homo erectus as earlier believed, but descended from a lineage that left Africa roughly 1.75 million years ago [SD2017a].
In short, while some researchers are still unconvinced, the tide is turning strongly to the original hypothesis that the hobbits are a separate hominin species.
A closely related controversy is the status of a newly discovered species known as Australopithecus sediba (or A. sediba, for short), which was discovered by Lee Berger and his nine-year-old son Matthew in 2008. These fossils, which have been dated as between 1.977 and 1.980 million years ago, are also thought to be the true ancestors of Homo sapiens by some. This is based on findings such as its hands, which are more humanlike than that of Homo habilis, which other scientists believe was the proper ancestor. These controversies are summarized in a nicely written feature article in the April 2012 Scientific American [Wong2012]. This controversy re-erupted in 2014, when researchers at Tel Aviv University argued that the Australopithecus sediba fossils are, in fact, from two different hominin species, but the original discoverers of the fossils are not convinced [Wong2014a].
But recent findings have challenged this belief. In 2011 archaeologists announced that humans had reached the "Buttermilk Creek" site in Texas as early as 15,000 years ago [Wilford2011]. In 2012 archaeologists found some human artifacts in the Paisley Caves of Oregon that were independently dated to be as old as 14,500 years ago [Kaufman2012]. And in March 2013, archaeologists analyzing a site in Uruguay found remains, dated to 30,000 ago, indicating that humans were hunting giant sloths there at the time [Thompson2013]. Archaeologist Niede Guidon argues that humans arrived in South America 48,000 years ago, and perhaps even earlier [Romero2014].
These disputes came to a head in March, 2014, when a team of archaeologists found human drawings and human tools at a site in Brazil that has been dated to 22,000 years ago, fully 10,000 years before Clovis hunters appeared in North America [Romero2014]. Eric Boeda, a French archaeologist leading the excavations there, exulted, "The Clovis paradigm is finally buried." Still, others dispute the findings. Gary Haynes, an archaeologist at the University of Nevada, argued that perhaps the stones found there were not tools made by humans, but instead were chipped and broken by rockfall. Stuart Fiedel argued that monkeys might have made the tools instead of humans. But these dismissals have produced equally strong responses from other researchers. Vanderbilt archaeologist Tom Dillehay chimed back, "Riedel does not know what he is talking about," noting that the tools found at the site are similar to tools found at a site in Chile [Romero2014]. Additional research is planned by several teams to resolve the controversy.
In 2012, this controversy erupted again with the publication of Wilson's book The Social Conqueset of Earth, which promoted group selection in human evolution and culture. In a review, biologist British Richard Dawkins blasted the book as having "a slew of mistakes" [Dawkins2012]. Wilson responded, "If science depended on rhetoric and polls, we would still be burning objects with phlogiston [a mythical fire-like element] and navigating with geocentric maps" [Thorpe2012]. Evolutionary psychologist Steven Pinker weighed in by declaring that "the more carefully you think about group selection the less sense it makes, and the more poorly it fits the facts of human psychology and history" [Pinker2012]. Martin Nowak then defended group selection in a Scientific American article [Nowak2012]. The continuing controversy, with a summary of the arguments on both sides, is summarized in a July 2012 Scientific American commentary [Johnson2012].
These difficulties had led even long-time supporters of inflation to question the theory's viability. Paul Steinhardt of Princeton University is one vocal detractor. In 2012 he declared, "We thought that inflation predicted a smooth, flat universe. Instead, it predicts every possibility an infinite number of times. We're back to square one." Similarly, Sean Carroll, a CalTech cosmologist, explains, "Inflation is still the dominant paradigm, but we've become a lot less convinced that it's obviously true. ... If you pick a universe out of a hat, it's not going to be one that starts with inflation." [Steinhardt2011; Gefter2012; Ijjas2017; Moskowitz2014]. See Big bang and Inflation for more details.
But recently a group of physicists at the Niels Bohr Institute in Denmark published a paper casting doubt on these discoveries, claiming that they had found unexplained correlations in the noise produced by the detectors [Wolchover2018]. Two independent groups of researchers then embarked on a review of these results. They concluded their analyses by stating that the detections still stand: "We see no justification for lingering doubts about the discovery of gravitational waves," as one group's led by John Moffat of the Perimeter Institute for Theoretical Physics declared. But Andrew Jackson, who led the Copenhagen-based group that questioned the detection, called one of the exonerating reports "absolute rubbish," and also dismissed the findings of the second report. In response, Moffat wrote "The Copenhagen group refuse to accept that they may be wrong. ... In fact, they are wrong." [Wolchover2018]. Meanwhile, the LIGO team has announced new numerous new detections. So although most researchers are convinced that these detections are real, it is clear that the debate will continue for a while.
But string theory and the multiverse have their detractors, even among researchers intimately familiar with research in the field. Mathematician Peter Woit writes that "any further progress toward understanding the most fundamental constituents of the universe will require physicists to abandon the now ossified ideology of supersymmetry and superstring theory that has dominated the last two decades" [Woit2006, pg. 264]. In a similar vein, physicist Lee Smolin writes, in sharp criticism of the string theory-multiverse community [Smolin2006, pg. 352]:
We physicists need to confront the crisis facing us. A scientific theory that makes no predictions and therefore is not subject to experiment can never fail, but such a theory can never succeed either, as long as science stands for knowledge gained from rational argument borne out by evidence. There needs to be an honest evaluation of the wisdom of sticking to a research program that has failed after decades to find grounding in either experimental results or precise mathematical formulation. String theorists need to face the possibility that they will turn out to have been wrong and others right.
The other project, the Equation of State of Dark Energy (SHoES) project, relies on supernova measurements and the "cosmic distance ladder," namely a tiered system of reckoning of astronomical distances which starts with straightforward parallax measurements of nearby stars in the Milky Way, which are then used to calibrate distances measured by Cepheid pulsating stars in the Milky Way and neighboring galaxies, which are then used to calibrate measurements based on Type IA supernovas (see Distance for additional details). The SHoES project, which has recently refined their techniques, has concluded that H0 is 74.03, plus or minus 1.42. Needless to say, the two measurements are in disagreement by a greater difference than can easily be dismissed by standard experimental error. Adam Riess of Johns Hopkins University, who is a co-leader of the SHoES project, nonetheless sees the disagreement in a positive light [Ananthaswamy2019]:
At some point, you have to start saying the universe has another wrinkle in it, in the cosmological model -- in the composition of the universe or in some feature of dark matter or dark energy -- [that] could also potentially explain this. ... You have to give that some serious consideration.
In general, there is no evidence whatsoever that there is any sort of "conspiracy" or "group-think" among scientists in the areas of geology, evolution, physics or cosmology. To the contrary, when one peers beneath the smooth public veneer of the world of scientific research, one finds, more often than not, heated debates and disagreements, particularly at the forefront of research where genuine issues remain unresolved. In fact, in a real sense, virtually every scientific paper ever published (and hundreds of thousands are published each year) represents one voice in a debate, either supporting or debunking some other hypothesis or study. Indeed, it is utterly absurd to think that a "conspiracy" or "group-think" could persist more than momentarily in a worldwide community of hundreds of thousands of professional scientists, representing many different nations, cultures and religious traditions, who competitively critique each other's work in scientific journals and conferences, and who evaluate each other's research proposals in highly competitive bids for government funding.
Thus, while the system of scientific publication and peer review is not foolproof, and there have been lapses, nonetheless it works very well in rooting out sloppy reasoning, weak experimental support, as well as any attempts to impose an "orthodoxy" in the field. Scientific progress is real.
For additional discussion, see Conspiracy, Peer review and What is science?.