Friday, March 21, 2003

How to Write a Science Textbook A constant complaint among science educators is that their textbooks are written like reference books. This makes them exceedingly boring, and tends to present science as a series of disconnected facts, rather than as a process for obtaining information about the world. Now, from The Washington Post, comes this article about a new series of texts by writer Joy Hakim. According to the article, her texts take a storytelling approach to science, focussing in particular on the lives of various great scientists. This should help humanize the subject in the minds of children, which would be a considerable improvement over the current way of doing things.

Without having seen the books themselves, I will withold my full endorsement for now. But the general appoach seems to be just what the doctor ordered.

What About Math? It would be nice to have a similar set of textbooks for mathematics, my own subject. In the early years this would be difficult. Arithmetic is pretty much as old as history itself, and, as distasteful as it may seem, there are certain basic math skills students simply have to learn. But certainly we could work in more of a historical approach in high school algebra and geometry classes. For example, this term I am teaching a semester-long course dealing almost entirely with the history of those two subjects.

Mathematics is generally presented as a collection of poorly motivated rules for solving problems of dubious interest. Taking a more humanistic approach in early mathematical education could go a long way towards correcting tht impression.

Wednesday, March 19, 2003

Brief Hiatus I will be travelling quite a lot over the next two weeks, so posts will be sporadic during that time. Regular daily updates wil resume on Monday, March 31.

Tuesday, March 18, 2003

Elephant Snorkels? New research suggestes that the modern elephant evolved from aquatic mammals, with the trunk playing the role of a snorkel. The full report can be found in the article "The Developing Renal, Reproductive, and Respiratory Systems of the African Elephant Suggest an Aquatic Ancestry", available online here.

Monday, March 17, 2003

Creationist Mendacity One of the vilest organizations in American politics today is Focus on the Family, a Christian group that spends its time lobbying against gay rights, abortion, and the separation of church and state. Its leader is James Dobson, an eloquent snake-oil salesman who has the ear of CNN's Larry King and FoxNews' Hannity and Colmes. (Both are venues in which Dobsom is given large amounts of time to spout his hateful nonsense, without fear of being interrupted by an inquisitive host or another guest. This in our allegedly liberal media).

FOF also has a bee in its bonnet about evolution, and they devote a considerable amount of time towards efforts to inject some form of creationism into public-school science classrooms. The cover story of the current issue of their magazine "Citizen" is entitled Loosening Darwin's Grip and describes recent efforts in Cobb County, Georgia and the state of Ohio to have creationism placed in the standards.

Two Defeats for Creationism Proponents of intelligent-design theory (ID) initially wanted to have the standards require the teaching of ID in any science classroom where evolution is also being discussed. Once it became clear that this was a non-starter, they scaled back their ambitions to including vague changes in the language instead. For example, they wanted the definition of science changed to potentially allow supernatural explanations to be permissable in scientific discourse, or they wanted the standards to require "teaching the controversy" over evolution. "Teach the controversy" is a creationist euphemism for aloowing ID into the classrooms; that the controversy is entirely manufactured by a small group of religious demagogues does not seem to bother them.

Curiously, the old science standards in Ohio made no reference to evolution at all. The result of all of this ID agitation is that the new standards include quite a lot of evolution, and this is the only theory students will be tested on in state exams. The school board explicitly rejected ID, by including a statement that said, "The intent of this indicator does not mandate the teaching or testing of Intelligent Design." The only nod to ID was a vague statement to explain ways in which scientists critically analyze evolutionary theory, a point that was never at issue.

But in creationist fantasy-land it is a trivial matter to spin such total defeat into victory. The "Citizen" article makes the claim that "Altogether, 20,000 people contacted the state board, urging it to allow classrooms to 'teach the controversy'. That swayed the state board, which voted in December to adopt a teach-the-controversy policy." Actually, this is precisely what the school board did not mandate.

The sitaution in Cobb County, GA was much the same. ID proponents wanted a major change in educational policy to allow the teaching of ID. What they got was a strong statement in support of evolution and an explicit rejection of ID.

The "Citizen" article contains much else that is dishonest or misleading, and I will report on that in a subsequent post. More information on these subjects can be found at the National Center for Science Education or Ohio Citizens for Science.

DDT and Malaria The March 2003 issue of The Washington Monthly contains an interesting article by Alexander Gourevitch entitled "Better Living Through Chemistry." Alas, it is not available online, but it's worth tracking down the print version. The article makes a compelling case that controlled spraying of DDT in Africa could greatly reduce the number of cases of malaria,. which currently number in the hundreds of thousands. Unfortunatly, certain environmental groups are standing in the way of implementing such controlled sprayings.

The usefulness of DDT as an insecticide was discovered in 1939 by Paul Muller, who later won a Nobel Prize in medicine for his trouble. Extensive spraying of DDT in the two decades after WWII led to dramatic decreases in diseases, especially malaria, spread by mosquitoes and lice. The World Health Organization estimates that the number of lives saved as a result number in the millions. However, after many years of spraying some harmful side effects were discovered. Once it enters an ecosystem, DDT remains for a very long time. Eventually it builds up in substantial concentrations in animals, especially fish. It was also discovered to be a carcinogen in large doses. The last straw was when it was found that mosquitoes had developed a resistance to it (a fine example of evolution in action). These effects led the United States to ban the chemical in the early seventies.

Gourevitch points out that extenisve research since then has shown that DDT is harmful only in large doses. There is no evidence linking small quantities of DDT to harmful effects in humans. Furthermore, DDT remains effective as a repellant even in mosquitoes that have developed a resistance to it. There is no other known insecticide that can make that claim. Considering that malaria kills hundreds of thousands of years, which certainly makes it a known health risk, a sensible program of controlled spraying seems entirely reasonable.