Barbara Wright is very nice, for a heretic.
In her warm, cluttered little office on the fifth floor of The University of Montana's Health Sciences building, Wright entertains visitors with grandmotherly manners, a scientist's careful words and a touching nervousness about having her photo snapped. Occasionally, though, she starts talking like a subversive, the first clue that the UM geneticist is embroiled in a civil war, a battle over the very essence of evolution.
Embroiled she is, though, rebelling against some of genetics' most fiercely guarded conventional wisdom. Fresh off the publication of a controversial paper in one of America's leading scientific journals, Wright finds herself in the middle of a 200-year-old conflict over the cause and direction of biological change on planet Earth.
Wright is a Neo-Lamarckian, a latter-day supporter of Jean-Baptiste Lamarck, a French scientist who proposed that environmental factors directly affect the evolution of organisms. Like many of Lamarck's modern followers, Wright maintains that such environmental stresses are influencing the direction of evolution by causing specific genetic mutations.
|University research professor Barbara Wright has performed ground-breaking work in the field of biogenetics. “It’s hard, you know,” she said, “when you challenge current dogma, to get funding for research.”|
Photo by Chad Harder
"You can't even mention Lamarck," Wright says. "I mean, you get shot down. Historically, he was the first to propose that species evolve one from another. Now, he had some kind of strange ideas. He believed in what's called soft inheritance-that if your father lifted weights, you'll have strong arms. That stuff is gone, totally discredited, of course."
What survives is Lamarck's basic premise, that evolution occurs in response to specific factors in the outside world. Wright, along with former UM student Angelika Longacre and lab technician Jacqueline Reimers, wrote a paper supporting that concept, published this month in the National Academy of Science's Proceedings.
The paper is based on experiments with the E. coli bacteria, the same bug that makes its home in the human digestive tract. An E. coli generation lasts all of 20 minutes; when these bacteria start to mutate, they mutate fast.
The UM scientists deprived the bacteria of leucine, an amino acid they need to live and grow. Wright and company knew that this starvation would speed up the transcription of the E. coli's own leucine-making genes. During transcription-the essential process by which genetic information is passed on-DNA's familiar double-strand structure unravels. One strand becomes the basis for new enzymes that make amino acids. The other, left on its own, is vulnerable to mutation. Faster transcription means faster mutation.
Wright hypothesized that this specific environmental stress-the desperate need for leucine-would cause a specific mutation in the bacteria. And, voilá, it was done. The E. coli Wright had been starving soon developed the ability to make its own leucine. Starvation had caused more mutation in those genes specifically charged with making the substance. The bacteria had evolved to survive in an unfamiliar environment.
"The implication for evolution is that if you have a specific stress-you're starving for a specific amino acid, in this case-that activates a specific response, increased mutation rates where it will count the most," Wright says. "This is a model for how an organism acquires an ability necessary to live in a new environment."
To Wright this is common sense. To the Neo-Darwinists who've dominated genetics for a century, it's apostasy.
"Our work here is in direct conflict with the Neo-Darwinists, who are stricter than Darwin himself," Wright says. "They say there's no influence from the environment, direct or indirect, on variation. Everything in the scientific community has supported Neo-Darwinism."
According to Wright, Neo-Darwinism is guided by the notion that evolution is a one-way street: Information flows from DNA, which is constantly mutating spontaneously and without direction.
"If you're a scientist, I don't think you should be saying there's no cause for anything that happens," Wright says. "This idea that things 'just happen' in an evolutionary sense is a big part of the problem."
Wright feels her version of evolutionary process offers more nuance and complexity-and, she says, it only makes sense.
"Our work is in agreement with the work of certain mathematicians who've said that the rate of evolution has been proceeding much more rapidly than could be accounted for if all mutations were random and spontaneous," Wright says. "I mean, look what's happened in four billion years. It's just amazing. Most studies on evolution are at a descriptive level. This happened, then this happened, then this happened. But what is the mechanism by which change actually occurs? The studies will say, this new ability has been gained for this reason. But how? Well, here we have a mechanism by which a change occurs."
Wright clearly hopes that breaking into Proceedings will win her research more respect in a hostile scientific climate. If that happens, it will mark a big change from years in which she kept her work-combative as it is-under wraps, until she was convinced it was correct.
"I didn't let anyone work with me on this for years," she says. "I kept my students out of it for the longest time."