Saturday, October 15, 2005

"Evolution in life is essentially the whole enchilada"

So observed Dr. Kevin Padian, plaintiff’s final expert witness, whose testimony was the focus of day 9 of the Dover intelligent design trial.

Dr. Padian, is a professor in the Department of Integrative Biology and a Curator in the Museum of Paleontology at the University of California, Berkeley, where he has taught for 25 years. Dr. Padian has a bachelor's degree in Natural Science and a Masters of Arts in Teaching from Colgate University. (Vic Walczak, the ACLU of Pennsylvania's Legal Director also attended Colgate University for his undergraduate education).

Before going on to get his Ph.D. from Yale, Dr. Padian gained three years of what turns out to be very relevant experience - he taught life sciences to 6th and 7th graders. So he knows what it is like to teach science to teenagers.

At Yale, Dr. Padian wrote a dissertation on the structure, function, morphology and evolution of flight of pterosaurs (flying reptiles from the age of dinosaurs). His principal training is in evolutionary theory, paleontology, zoology and the history of science. He is the author or co-author of nearly 100 peer-reviewed papers and several books on topics such as the evolution of dinosaurs to the development of evolutionary thought.

Dr. Padian's testimony was a quick, but understandable, course on evolutionary theory. He showed how fossils, geology and molecular biology help explain how life has changed through time. He walked Judge Jones, the lawyers, and members of the audience through a series of graphs and images, patiently explaining their significance and interjecting some dry wit on numerous occasions. He frequently referred to "critters" when talking about living as well as extinct species.

Much of Dr. Padian's testimony was a critique of the pro-intelligent design book Of Pandas and People. Dr. Padian refuted many of the claims made in that book.

For example, Of Pandas and People states: "The problem is that there are no clear transitional fossils linking mammals to whales."

Dr. Padian testified about numerous transitional fossils that demonstrate the descent of whales from its early ancestors, a group of cloven-hoofed mammals. He illustrated the gradual evolution of features over time.

"We think the transitions are pretty good," Dr. Padian said.

Dr. Padian also explained why Of Pandas and People contained incorrect assertions about a lack of evidence that living things evolved. He showed how intelligent design proponents ignore lots of fossilized evidence and "a wealth of data" from molecular biology that support the finding that living things have evolved over millions of years.

Attentive listeners in the audience learned a lot about the evolutionary development of fish, birds, and mammals. They also learned that some scientists were thinking, writing and talking about evolution even before Charles Darwin was published. Darwin's big contribution was his work on natural selection.

Dr. Padian also explained what homology is - the study of similar characteristics of living organisms - and then discredited the assertions regarding homology contained in Of Pandas and People. Dr. Padian testified that: "Intelligent design proponents either do not understand or accept how scientists establish relationships among organisms."

Robert Muise, one of the attorneys representing the school district, cross-examined Dr. Padian. Muise asked about Stephen Jay Gould's theory of punctuated equilibrium. Gould thought that evolution could be better described as taking place in fits and starts. Padian indicated that he thought Gould offered this theory as a possible explanation for gaps in the fossil record.

Muise then asked: "Is natural selection responsible for punctuated equilibrium?"

"That's a great question," responded Dr. Padian. He then went on to state that while Gould's theory of punctuated equilibrium may raise questions about the mechanism of evolution it does not contradict the idea of common descent.

Muise also asked about Dr. Padian's referring to the Cambrian Explosion, 500 million years ago, as a period when there was an abrupt appearance of life. Dr. Padian acknowledged that he and other scientists have used the word "abrupt" in that context and that they mean "that's the first place where we found it." Dr. Padian added that the abrupt appearance did not conflict with the tons of scientific evidence that morphological changes have occurred.

Two of the plaintiffs also testified at the trial on Day 9. They talked about how they were harmed by the Dover intelligent design policy. Steven Stough said "They have usurped my authority to be the one in charge of my daughter's religious education."

Stough also testified that his daughter would probably be asked to be excused during the reading of the intelligent design statement unless the court overturned the policy. When asked to describe what consequences his daughter would suffer, Stough replied: "She's harmed by that because she's no longer part of the accepted school community."

Among those in attendance for the morning session were Vic Walczak's parents, wife and three children.

Submitted by Larry Frankel, legislative director, ACLU of Pennsylvania

2 Comments:

Anonymous Peter G said...

Another fine overview of Dr. Padian's testimony is in Mike Argento's column in the York Daily Record Saturday.

8:33 PM  
Anonymous Peter G said...

Oops. Very wrong link! So sorry. This is Argento's column on Dr. Padian's testimony.

8:37 PM  

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