A conference on evolution to be held this week at the Vatican is a sign that for many devout Christians, there is no conflict between the ideas of Charles Darwin and faith in God.

Devout Christians often are portrayed as if they view evolutionary biology as an attack on the Bible's account of creation, and scientists are portrayed as atheists. While there are high-profile examples of both, a truce was reached long ago in most major Christian traditions, including some streams of evangelicalism.

The Vatican conference, which marks the 150th anniversary of Darwin's "On the Origin of Species," is one example of scientists and theologians working together to transcend the culture wars and forge a lasting peace.

At the conference, which runs Tuesday through Saturday, scientists and theologians will discuss how to collaborate without trespassing in each others' area of expertise.

Locally, Duquesne University will mark the anniversary with an address by Francisco Ayala, a professor of biology and philosophy at the University of California, Irvine. He will address similar issues at 7 p.m. March 18 in the Power Center ballroom.

The Catholic Church has never had a rigid reading of Genesis. The third century theologian, Origen, pointed out that the Bible says God created light three days before creating the sun, moon and stars.

"He concluded that the passage was speaking figuratively about realities other than scientific truth claims," said Bill Wright, who teaches biblical studies at Duquesne.

"These chapters in Genesis are an answer to fundamental questions about who God is and what a human being is, but they address those questions in symbolic and figurative language."

There was a lapse in 1633, when the Vatican forced Galileo to recant his theory that the earth orbited the sun. That later embarrassed church leaders, who formally approved his work in 1741. Later popes were more careful in response to Darwin.

While objecting to scientists who strayed into theology if they claimed evolution disproved God, the church did not condemn the scientific theory. But for 90 years it kept a tight lid on theological discussion of it.

"It was a protective reaction," said George Worgul, chairman of Duquesne's theology department.

As Catholic theologians quietly pondered into the 20th century, a consensus grew that what mattered was not the origin of the human body, but of the human soul, he said. Belief grew that God could have willed evolution as the dynamic of creation, then crowned humans with a soul that mirrored his image.

"So there was an attempt to work out a way to recognize the legitimate data from science that human beings have evolved, while affirming that this is not apart from God," he said.

In 1950 Pope Pius XII brought discussions into the open when he called evolution a theory worthy of exploration. Pope John Paul II went further in 1996, calling it "more than a hypothesis."

In 2006 Pope Benedict hosted a small conference, published as "Creation and Evolution." He falls within the camp of theistic evolution, the belief that God created the process of evolution.

Evangelicalism covered similar ground by a twisting path.

Evangelical intellectuals of the 1860s accepted evolution, said Mark Noll, a historian of American evangelicalism at the University of Notre Dame. Princeton theologian B. B. Warfield, who drafted a classic doctrine stating that the original manuscripts of the Bible had no factual errors, had no quarrel with the idea.

"He was always very careful to say that it's a God-ordained and God-directed process. But he doesn't think that the science, per se, is a problem," Dr. Noll said.

Reaction against Darwin was more common among those without advanced theological education, particularly if they had come to faith through the popular books of Anglican priest William Paley, who argued for the existence of God based on evidence of design in nature.

But by the 1930s, even fundamentalists were trying to harmonize biblical literalism with evidence of a very old earth. Despite hype over the Scopes "monkey trial" in 1925 -- in which a Tennessee science teacher was fined for teaching evolution -- the real battles began in the late 1950s, Dr. Noll said.

As the space race launched, Washington overhauled science education. Local curricula were replaced with textbooks that lacked sensitivity to students' religious beliefs, Dr. Noll said. Many conservative Christians felt science classes promoted atheism. They pushed back with books that attacked evidence for evolution.

"That wasn't new, but it hardened into a cultural position," Dr. Noll said.

Denis Lamoureux, 54, an evolutionary biologist who teaches on science and religion at the University of Alberta, Canada, has written extensively on the religious conflict over evolution. He has fought on both sides.

He was raised Catholic, but with no knowledge of his church's nuanced views on evolution. His first college biology class convinced him that the Bible was ridiculous. He graduated from dental school as an atheist.

Later he turned back to Jesus, this time as an evangelical. He blamed evolution for his earlier loss of faith, and decided to earn a doctorate in evolutionary biology to disprove it.

Along the way he also earned two master's degrees from an evangelical seminary. There, he was shocked to conclude that he had been reading Genesis wrong. He initially had read it as a technical document. But study of ancient literature convinced him it was intended to tell truths about humanity and God that had nothing to do with biology.

He clung to the belief that evolution was wrong until his own studies of fossil teeth showed him that creationists were wrong when they said no one had ever found a fossil in evolutionary transition.

"I started seeing tons of those, over and over and over again. I started seeing that there is a process that allows us to evolve," he said.

He flirted with the intelligent design movement, but rejected it. He is a theistic evolutionist, who believes God chose to create through the process of evolution. He views intelligent design as requiring God's direction from outside the natural process, and remains a strong evangelical.

Among theologians from many Christian traditions, conversations have moved beyond the fact of evolution to its moral implications for humanity, Dr. Worgul, of Duquesne University, said.

"The whole question of evolution is an ethical question. We are now in a position where, in some cases, we are able to manipulate creation. That gets us into questions of should we be able to manipulate ourselves as part of creation," he said.

"That is why this third stage is going to be the most important question of all. If you see the human being apart from God or in relationship to God, you may arrive at very different answers to those questions."