For a university professor, Francisco J. Ayala spends a lot of time on the road.
An evolutionary biologist and geneticist at the University of California, Irvine, he speaks often at universities, in churches, for social groups and elsewhere, usually in defense of the theory of evolution and against the arguments of creationism and its ideological cousin, intelligent design.
Usually he preaches to the converted. But not always.
As challenges to the teaching of evolution continue to emerge, legislators debate measures equating the teaching of creationism with academic freedom and a new movie links Darwin to evils ranging from the suppression of free speech to the Holocaust, “I get a lot of people who don’t know what to think,” Dr. Ayala said. “Or they believe in intelligent design but they want to hear.”
Dr. Ayala, a former Dominican priest, said he told his audiences not just that evolution is a well-corroborated scientific theory, but also that belief in evolution does not rule out belief in God. In fact, he said, evolution “is more consistent with belief in a personal god than intelligent design. If God has designed organisms, he has a lot to account for.”
Consider, he said, that at least 20 percent of pregnancies are known to end in spontaneous abortion. If that results from divinely inspired anatomy, Dr. Ayala said, “God is the greatest abortionist of them all.”
Or consider, he said, the “sadism” in parasites that live by devouring their hosts, or the mating habits of insects like female midges, tiny flies that fertilize their eggs by consuming their mates’ genitals, along with all their other parts.
For the midges, Dr. Ayala said, “it makes evolutionary sense. If you are a male and you have mated, the best thing you can do for your genes is to be eaten.” But if God or some other intelligent agent made things this way on purpose, he said, “then he is a sadist, he certainly does odd things and he is a lousy engineer.”
That is also the message of his latest book, “Darwin’s Gift to Science and Religion” (Joseph Henry Press, 2007). In it, he writes that as a theology student in Spain he had been taught that evolution “provided the ‘missing link’ in the explanation of evil in the world” — a defense of God’s goodness and omnipotence, despite the existence of evil.
“As floods and drought were a necessary consequence of the fabric of the physical world, predators and parasites, dysfunctions and diseases were a consequence of the evolution of life,” he writes. “They were not a result of a deficient or malevolent design.”
Dr. Ayala gives about 50 talks a year, he said in a recent interview in New York, a day after he delivered the inaugural Louis Levine-Gabriella de Beer lecture in genetics at City College. (He had spoken the day before, at North Carolina State University, on the evolution of morality, and spoke two days later at McGill University in Montreal, where his subject was Darwinism and religion.)
Because of his eminence — he is a member of the National Academy of Sciences, a former president of the American Association for the Advancement of Science and a winner of the National Medal of Science — Dr. Ayala “has a bully pulpit,” said Eugenie Scott, who heads the National Center for Science Education, a group that advocates for the teaching of evolution and against creationism in public schools. “When Francisco speaks, people listen.”
But Dr. Ayala said another proposed engagement, at a conference at the Crystal Cathedral in Garden Grove, Calif., a 10,000-member church that is the base for the “Hour of Power,” a weekly televised religious service, was canceled earlier this year. A spokesman for the organization said Dr. Ayala’s talk was canceled “due to overbooking” of speakers.
Dr. Ayala said the event’s organizers wanted him to be introduced by Ben Stein, a writer (and business columnist for The New York Times) who is the star of the new anti-evolution movie, “Expelled,” and wanted to show the film in conjunction with his talk.
“I don’t mind who introduces me,” he said he told them, “but I would not want the film to be part of my presentation. They said they could not meet my conditions.”
Despite his heavy travel schedule, he continues to teach and research and publish, and work on Academy committees. He has been an opera lover since childhood, when he saw “Aida,” complete with elephants, in a Madrid park. And he is on the boards of Opera Pacific and the Pacific Symphony, both based in Orange County, Calif.
But his major outside interest is wine, specifically the vineyards he and his wife, Hana, own in Sacramento and San Joaquin Counties in Northern California, where they produce grapes for several wineries. In June, he will give a talk on wine and health, but as a wine lover. “I will not be talking much about health,” Dr. Ayala said.
The couple got into the wine business almost by accident in the 1980s when Dr. Ayala was at the University of California at Davis, near Sacramento. Property he and his wife bought as a weekend getaway turned out to have acres of vines, he said, and over the years they have expanded their holdings to 6,000 acres.
His secret for keeping all these enterprises going is “organization,” by which he means hiring what he called “superb” staff members and leaving them alone to get things done. He visits the vineyards perhaps once a month, he said, and stays on top of things by chatting with his manager by cellphone once or twice a week as he walks the mile from his home to his office on the Irvine campus.
His assistant there, Denise Chilcote, runs his professorial life, taking his phone calls, making his appointments and answering his e-mail, often signing his name.
Dr. Ayala, who is 74, was born in Madrid and studied theology at the Pontifical Faculty of San Esteban in Salamanca before coming to the United States in 1961, for graduate study in genetics at Columbia. From there he went to Rockefeller University, then Davis and then to Irvine. He became a United States citizen in 1971. He and his wife, an ecologist who works to encourage conservation efforts by resorts in tropical areas, have two grown sons.
Dr. Ayala said he remained surprised at how many Americans believe the theory of evolution is contrary to belief in God, or that the theory is erroneous or even fraudulent. (In fact, there is no credible scientific challenge to it as an explanation for the complexity and diversity of life on earth.)
Sometimes, he says, people come to his talks determined to challenge him, usually by citing familiar creationist arguments — that a body part like the bacterial tail, or flagellum, is too complex to have arisen through evolution, or that scientists lied when they demonstrated that moths in England evolved to be darker as the Industrial Revolution covered their native trees with soot.
But he said he had yet to encounter a challenge he could not meet. When people ask about the bacterial flagellum, for example, “I bring up that by now it has been worked out in great detail how the basic parts of the bacterial flagellum have evolved independently and exist independently,” he said.
As for the moths, he conceded that in famous photographs illustrating the discovery, the dark moths had been glued to the dark trees. But the observation that the moths had darkened along with the trees was real, he said. “To have a nice photograph, we glue them,” he said. “That is not falsifying science. That is something for facilitating teaching.”
And he dismisses the argument that it is only fair to teach both sides of the evolution/creationism controversy. “We don’t teach alchemy along with chemistry,” he said. “We don’t teach witchcraft along with medicine. We don’t teach astrology with astronomy.”
He said he was saddened when he saw the embrace of evolution identified with, as he put it, “explicit atheism,” as in the books of the evolutionary biologist Richard Dawkins or other writers on science and faith.
Neither the existence nor nonexistence of God is susceptible to scientific proof, Dr. Ayala said, and equating science with the abandonment of religion “fits the prejudices” of advocates of intelligent design and other creationist ideas.
“Science and religion concern nonoverlapping realms of knowledge,” he writes in the new book. “It is only when assertions are made beyond their legitimate boundaries that evolutionary theory and religious belief appear to be antithetical.”
It is important that Dr. Ayala “is not a religion-basher,” Dr. Scott said, “because creationists always showcase the religion-bashers in science as if they speak for all scientists. They clearly do not speak for Francisco and many others.”
Nevertheless, Dr. Ayala will not say whether he remains a religious believer.
“I don’t want to be tagged,” he said. “By one side or the other.”