thinkevolution.net

The Philadelphia Inquirer published an article on April 2 reporting research findings on the sex roles of our hominid ancestors. It includes a reference to a new book, The Invisible Sex: Uncovering the True Roles of Women in Prehistory by James Adovasio, Olga Soffer and Jake Page. Perhaps the most prominent message in the article is that current paleoanthropology research is invested in studying human evolution from an equal-rights-minded perspective, while past research has chauvinistically and perhaps inaccurately emphasized the machismo of early man’s big-game hunting achievements. No doubt this enlightened effort to consider the importance of early woman’s labors to our extant existence reflects our recent cultural evolution towards gender equality. Bravo in this regard. And while I’ll never criticize the popular media for reporting on, nor researchers from researching, the evolutionary history of the species we’re all most interested in (our own), the fact remains that inferring evolutionary dynamics from ancient fragments of bones and tools is nearly impossible. The opacity of this problem is well illustrated by just how easily influenced the scientific perspective is by the social politics of our culture at large.

Still, there’s a big difference between making the most of the data you’ve got—and the validity of these researchers’ scientific conclusions should be evaluated by the rigor of their scientific method—and flat-out naivety or, worse, disingenuousness. At the end of the article, Stanford anthropologist Richard Klein is reported as saying that a mutation in the lineage of early humans may be responsible for our eventual success, as opposed to the eventual extinction of the related Neanderthal lineage. This point comes after a dramatic description of humans emerging into a “cultural” and “artistic” existence of sophisticated “conceptual thinking,” the implication being that our superior intellectual powers should be credited with saving us from extinction. (There’s no way to know this, either: another example of human bias?) But hand-waving aside, there are some things we DO understand rather well, and the extraordinarily complex, quantitative nature of human biology is one of them. No geneticist or evolutionary biologist would ever think that a single mutation could induce such a dramatic new phenotype, so why should an anthropologist (or reporter)? The truth is almost certainly that multiple mutations distinguished our early human ancestors from their Neanderthal neighbors. This may be less easily dramatized to a non-scientific audience, but I argue strenuously that an accurate representation of the scientific process is as critical in an agenda for general science education as is whether scientific research is reported at all.

NOTE: This post was originally published on February 28, 2007, on an old version of this site.

In discussing Stephen Jay Gould and Richard Lewontin’s article “The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme” with a group of undergraduates the other day, one of the students asked if this critique, published in 1979, is still relevant. Gould and Lewontin’s basic thesis is that too many biologists fall prey to the seduction of describing everything they see as an adaptation. They accuse their colleagues of inappropriately dissecting organisms into discrete traits, then conjuring adaptive explanations for the existence of these traits—a process that not only neglects to provide evidence to justify such an adaptive explanation, but that also fails to consider how evolution is a whole-organism process. Well, today I have a definitive answer: it is as relevant as ever.

Today Marty Moss-Coane interviewed guest Sharon Moalem on her show Radio Times. Dr. Moalem, author of Survival of the Sickest, a book about how many human diseases are in fact adaptive “complicated blessings,” paraded a series of sophomoric explanations for how susceptabilities to many human diseases have in fact been selected for over our evolutionary history.

For example, Moalem argues that the relatively high frequency of genes that underlie the disease hemochromatosis in populations of European descendants may be the result of selection for these genes during the plagues of Europe. Hemochromatosis is a disorder in which iron accumulates in body tissue, and macrophages—which are a part of the immune system—suffer an iron deficiency. Because some pathogens may depend on iron to escape attack by the immune system, and because descendants from countries with high plague casualties show high frequencies of hemochromatosis, Moalem makes the argument that Europeans with iron-deficient macrophages were more likely to survive the plague… and thus we see a disproportionate representation of hemochromatosis in European descendants. But wait a minute! Correlation must not be confused with causation. If the genes that cause hemochromatosis are so detrimental, why were they not purged from the population before the plagues began? Maybe new mutations are popping up, or maybe selection is too weak to purge these alleles from the population. Or perhaps there has been positive selection for some of these genes, but we have no direct evidence that it was to avoid dying from the plague. It may be the case that the genes that underlie hemochromatosis also perform a beneficial function elsewhere in the body.

Furthermore, Moalem uses spurious scientific data to spin his adaptation stories. For example, he reports that fewer boy babies than girl babies were born in New York city after 9/11. Apparently there are some data suggesting that gestation of a male fetus incurs a higher cost to the mother, and that under stress, a mother will be more likely to miscarry if she’s carrying a high-cost son. Nevermind that this phenomenon deserves skeptical examination—the statistics that claim a significant gender skew in New York births can be easily dismissed, thus debunking Moalem’s claim that the 9/11 attacks stressed out pregnant mothers and caused a slight decrease in the boy/girl newborn ratio. The failure of this study is quite straightforward. The authors compute birth ratios for 81 different time intervals in New York city: 71 intervals leading up to 9/11, and 10 inervals after 9/11. The authors claim that the lowest boy/girl ratio occurred in one of the 10 post-9/11 intervals, and that it deviated “significantly” from the average ratio over all 81 intervals. Their data do show that the lowest ratio occurred post-9/11, but it is not significant. Fluctuations in birth ratios, just as in any natural phenomena, will occur due to randomness. (And in fact, the sex ratio went up more often than it when down in the 10 intervals after 9/11!) Statistics allow us to infer whether a fluctuation differs enough from the average to suggest something unusal, and when looking at multiple events, a statistician must correct for multiple tests. Quite simply, these authors performed the correct test but utterly failed to adjust the type I error value to accommodate the type of data they were examining. The truth is that there is absolutely no evidence that birth ratios changed at all in response to the 9/11 attacks. To see what p-values should have been reported, see this criticism.

Radio Times is broadcast every weekday from the Philadelphia NPR station WHYY, 90.9 FM. You can listen to this particular show from the Radio Times archive.

NOTE: This post was originally published on December 18, 2006, on an old version of this site.

The New York Times published an article today reporting that a Kearney, NJ high school student has criticized his history teacher for proselytizing evangelical Christianity. David Paszkiewicz has been accused of telling his 11th-grade public school class “that evolution and the Big Bang were not scientific, that dinosaurs were aboard Noah’s ark, and that only Christians had a place in heaven.” Sixteen-year-old student Matthew LaClair was uncomfortable with these statements and brought the teacher’s actions to the attention of the administration.

Perhaps somewhat surprising is the amount of support for the teacher, who has clearly violated the First Amendment, and the amount of criticism for the complaining student. Another student and member of Mr. Paszkiewicz’s youth group, Greice Coelho, criticized Matthew LaClair, erroneously claiming that he is “ignoring the First Amendment to the United States Constitution, which gives every citizen the freedom of religion.”

This comment tidily demonstrates a warning Judge John Jones made in the December 13 panel discussion, in which he observed that many Americans are deficient in their civics education. He said the Dover case revealed that many people don’t understand their rights, and when they don’t understand them, they are much more likely to lose them.

NOTE: This post was originally published on December 13, 2006, on an old version of this site.

Today the Franklin Institute held a panel discussion on “Science, Faith and Darwin.” A recording of the discussion can be found here. Participants included:

1. Dr. Arthur Caplan, Director of the Center for Bioethics at the University of Pennsylvania, moderator
2. Dr. Michael Weisberg, Assistant Professor of Philosophy at the University of Pennsylvania, panelist
3. Dr. Michael Shermer, author and founder of the Skeptics Society, panelist
4. Eric Rothschild, Esq., Pepper Hamilton LLP, panelist
5. Stephen Harvey, Esq., Pepper Hamilton LLP, panelist
6. Judge John Jones III, U.S. District Court, Middle District of Pennsylvania, panelist

Michael Weisberg opened the panel with a powerful point about our history of accepting scientific explanations in the context of religion. By the middle of the 19th century, Newtonian physics had provided a spectacularly successful unifying explanation for the movement of the heavens and the motions of objects on earth. Both scientists and the public agreed on these explanations, and God’s role was somewhat displaced—though not necessarily removed, as the religious perspective remained that God initiated, for example, the movement of the solar system. However, these powerful physical theories simply could not explain the intricate complexities of biology, and a sort of pseudo-scientific set of explanations, invoking God as a creator, were established. Thus when Darwin proposed the first fully satisfactory scientific explanation for biological diversity, in which God was no longer required to explain certain mystifying gaps in our understanding, some people felt that the actual concept of God was being challenged. Weisberg concludes by saying that it is perfectly reasonable to accept the position that the Anglican Church held at Darwin’s death, and still holds: that biological science can illuminate truths about the world, without threatening a conventional religious belief in God.

Stephen Harvey tidily summarized the achievement of the prosecution in the Kitzmiller vs. Dover Area School District case, for which he and Eric Rothschild were the lead attorneys:

1. The prosecution proved that the Dover area school district acted with the purpose of promoting religion.
2. The prosecution proved that intelligent design is religious.
3. The prosecution proved that intelligent design is not science.

Harvey mentioned that when he and Rothschild first took the case, their colleagues joked that the case was “Harvey and Rothschild vs. God.” But he emphasizes that actually, following the facts of the case itself, Kitzmiller vs. Dover was not a case of faith versus science, and that their position was not anti-religion or anti-God. “Religion thrives in this country, not despite the separation of church and state, but because of it.” Really, the case was about making sure that a public school science classroom was not used as a pulpit to promote anyone’s specific religious perspective. Judge John Jones, who presided over the case, made the startling point that Kitzmiller vs. Dover made it apparent to him just how deficient the American public is in their civics education, not just their science education.

Of particular note, I think, is that each of the panelists emphasized frustration at the anti-evolution argument that science and theism are mutually exclusive, not just frustration at attacks on evolution. These authorities are clearly devoted to respecting both science the possibility of God. Michael Shermer openly declared himself an agnostic (like Darwin), and in fact a militant one: “I don’t know and you don’t either!” Stephen Harvey described himself as a Roman Catholic, and deconstructed the fallacy of one of the major arguments in intelligent design. Irreducible complexity is a fundamental concept in ID, and Harvey explained that, like other religiously motivated attacks on evolution, it is not proof of an intelligent designer, but instead an illogical, contrived dualism that posits that there are only two mutually exclusive possibilities: science or creationism, and that evidence against one is proof for the other.

One of the best questions of the evening inquired where, exactly, can religion be raised in a public school? The complexity of the answers by the panel reflects the overwhelming tension over religion in our culture. Michael Shermer was enthusiastic about the idea of discussing religion in history or philosophy class, he maintained only that it may not be incorporated into a science curriculum. John Jones pointed out that trouble begins when any teachings in this area become mandatory. Eric Rothschild was also enthusiastic about the idea of a comparative religions class at the high school level, much as they exist in higher education, but conceded that they must be non-biased and non-proselytizing and the potential for abuse is high given that school boards are governed at the local level. Stephen Harvey also pointed out that the potential for divisiveness in a school district would be tremendous.

NOTE: This post was originally published on November 23, 2006, on an old version of this site.

Today Marty Moss-Coane interviewed Michael Shermer, author of Why Darwin Matters: The Case Against Intelligent Design. In his book, Shermer writes, “Darwin matters because evolution matters. Evolution matters because science matters. Science matters because it is the preeminent story of our age, an epic saga about who we are, where we came from and where we are going.” Shermer is a former creationist who now defends evolution and explains that it makes “good theology” and that we need not find it contradictory to religious belief. He is the publisher of Skeptic magazine, columnist for Scientific American and founder of the Skeptics Society. Marty Moss-Coane is the host of Radio Times, a daily radio show from NPR radio station WHYY, 90.9 FM in Philadelphia, PA. You can listen to this show from the Radio Times archive.

Michael Shermer makes an intelligent and educated case for integrating science with religious belief. He points out that the theory of gravity, which explains the formation of planets and our solar system, is not contradicted by Christians in our country; it is largely accepted that this is “how God did it.” I agree perfectly with his argument that evolution need not challenge faith either. Science simply offers explanation of the world we live in. I particularly like Shermer’s insistence that, fundamentally, science can’t contradict faith, because science is the best tool we have for illuminating the world we live in, and no one should feel threatened by that.

Shermer directly confronts intelligent design as a guise for creationism and points out that the anti-evolution philosophy suffers from a specific fallacy of pseudoscience. Intelligent design abandons the quest for knowledge at the precise point at which it is most critical: while science seeks to investigate those things that we don’t understand, intelligent design invokes the “irrevocably complex” cause when our knowledge of a system is incomplete. He points out that this pseudoscientific process of “chasing the gaps” and using God as an explanation for those things that we do not fully understand is the opposite of how science works. Hence these arguments for God or a creator may be philosophical or theological, but not scientific.

Shermer also made an interesting point that I had never heard before. In explaining Charles Darwin’s argument that the evolutionary environment of our ancestors, which included important social interactions and group cooperation, may have played a role in developing a natural moral code, he points out that most conservatives and Christians do believe that we all have innate dispositions. It is typically liberals who try to explain human behavior by external influences. However, these perspectives are perfectly reversed when it comes to an explanation of sexual orientation! Conservatives and Christians are more likely to believe that homosexuality is environmentally influenced or chosen, while liberals typically argue that sexual orientation is innate.