An effort by biology teachers to accurately define evolution, a topic they must present in the nation's high schools, has split top American evolutionists over the correct approach to take. The dividing line is whether presentation of Charles Darwin's idea about the origin of natural diversity, including humans, must sidestep the question of God's existence or rebut it head-on.
"There seems to be in the social discussion a lot of confusion on what evolution is," said Alvin Plantinga, a University of Notre Dame philosopher whose fall letter to the National Association of Biology Teachers (NABT) spurred the new debate.
The letter prompted the NABT board, which represents 8,000 biology teachers, to alter a key paragraph in its statement on teaching evolution so it did not offend religious Americans.
In protest, another group of ardent evolutionists said the move was an unnecessary concession to creationists.
The NABT asked critics to submit alternatives that might unite biologists on the issue. "At NABT we welcome an open and honest debate on the merits," said Wayne Carley, executive director of the NABT.
"It is a living document," he said of the organization's three-page 1995 "Statement on the Teaching of Evolution." "I don't anticipate more changes in the document soon."
Mr. Plantinga said that Darwinism presents the concepts of "descent with modification" and the rise of new species by natural selection - but that many Darwinists also conclude that evolution refutes God's existence.
"The first two seem like appropriate scientific themes," Mr. Plantinga said. "The third seems like a theological gloss."
His letter to the NABT last fall, also signed by world religions scholar Huston Smith, questioned the association's saying that evolution is an "unsupervised, impersonal" natural process.
That might offend many Americans, Mr. Plantinga and Mr. Smith added, because 90 percent of them believe "a personal agent - God - supervised in some way our arrival on the planet."
Mr. Carley now agrees. "To say that evolution is unsupervised is to make a theological statement," not a scientific one, he said.
The NABT board meeting in October at first voted against dropping the words "unsupervised" and "impersonal." Later, at the urging of Eugenie Scott, director of the National Center for Science Education (NCSE), an anti-creationist group, a new vote favored the deletion.
Then battle lines were drawn among evolutionists.
University of Tennessee botanist Massimo Pigliucci issued a protest statement. To date, it has garnered the signatures of more than 100 evolutionists.
Dropping the two words "represents the first wedge of a movement intended to surreptitiously introduce religious teachings into our public schools," Mr. Pigliucci's statement said.
In an interview yesterday, he said he is working with other biologists to draft new wording that does not compromise but also does not insult American believers.
"It is not going to be perceived as `in-your-face,' " like the 1995 statement, Mr. Pigliucci said. "But evolution will be presented as a naturalistic process."
His group will submit their alternative to the NABT board. His co-writers include Harvard geneticist Richard Lewontin and Brian Charlesworth, president of the Society for the Study of Evolution.
After the protest earlier this month, Mrs. Scott of the NCSE circulated her response to what she called "l'affaire NABT."
"NABT was not knuckling under to creationist pressure, but responding in a responsible manner to a perception on the part of religious Americans that it was making an antireligious statement," Mrs. Scott said.…