Sunday, June 28, 2009

An exam from May 9th, 1941

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"1941 science test shows how things have changed"


Dan Vergano

June 27th, 2009


Some of us might rather forget our old science exams. But sometimes they still have lessons to offer.

For example, take a 1941 exam unearthed by one anatomy professor. The test is a relic of a simpler time that tells us a lot about the evolution of studying evolution.

"I just found the exam in one of my wife's old textbooks," says Casey Holliday of Marshall University in Huntington, W.Va. Folded inside a copy of the 1937 Man and the Vertebrates by Alfred Romer (a sage in reptile anatomy circles), the acetate copy of a 13-question "Zoology 1B" exam, dated May 9, 1941, intrigued Holliday.

"Some things haven't changed, these are still questions we'd ask in an introductory class," he says. A little detective work with the names stamped inside the book suggest the test (or perhaps an exam review) was given by UCLA professor E. L. Lazier on that date to his students. At the time, biologists knew that fossil evidence showed that new species evolved from older ones, sharing many of their characteristics, but the discovery of DNA was still 12 years away.

"What they had were fossils, and the system of classifying species we still use today," Holliday says. The first nine questions of the exam could appears on tests today with the same answers, he says. "A lot of memorization, just knowing the different classes of species, that's no different that what I ask students on my exams."

Lampreys and hagfish, jawless fish belonging to an ancient class called Agatha figure in the exam, and are still often discussed in evolutionary biology, for example, where researchers debate the evolution of the jaw, necessary for eating all sorts of food.

What makes the 1941 test a fossil in its own right is that it doesn't mention DNA, or molecular biology, in its questions about evolution, he adds. A June report in the Nature journal about a newly-discovered dinosaur fossil, for example, feeds the measurements of the 155-million-year-old creature into debate about the evolution of bird digits. But today, evolutionary biologists also have a great deal of information about the genes driving development of those digits, Holliday says, illuminating unexpected links between species and complicating the argument.

As we all recall, tests work up to hard questions, and the 11th one on the 1941 exam asks whether whole new classes of back-boned species arise from unique, fairly recent ancestors or from early, more primitive life. "That's still a really big question today," Holliday says, although we can point to birds evolving from highly-specialized feathered dinosaurs and crocodiles (Holliday's specialty) evolving from highly-specialized reptiles that walked on their hind legs to support one side of the argument.

Paleontologists don't use the word "primitive" anymore to describe features on fossils, he adds. The word smacks too strongly of older views of inevitable progress in the fossil record, rather than acceptance that changes are driven by natural selection, with inherited traits that better the chances of survival making it more likely for creatures to reproduce and pass on those traits. "We only use 'primitive' when we are making fun of someone else's fossils," Holliday says.

Still, modern-day tests look like evolutionary descendants of the 1941 exam, he says. "It's old, but it sure looks like something from an introductory zoology exam we'd give today."

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