Jesus and genetics:Thorny questions revolve around Christ's Y chromosome
Darwin's evolution still stands out as the thorniest point of contention between science and religion, but other more recent scientific advances also raise new questions for believers.
How, for example, does the 20th century's biological revolution influence the Christian concept of virgin birth? Where did Jesus get his DNA? His Y chromosome?
A number of scientifically minded Christians have come forward during the Dover "intelligent design" trial to say they accept that ordinary humans arose through purely natural processes, no intelligent design needed. But it's another thing to accept that the Lord and Savior was conceived through an act of sex.
For centuries it was understood that sex preceded pregnancy, but what exactly happened to create the baby was shrouded in mystery. Not until the 1600s, with the advent of the microscope, did scientists learn about the role of sperm in triggering development.
Sperm aren't always necessary. Some female lizards, fish and other creatures can procreate through parthenogenesis (Greek for virgin birth). Cloning allows something similar in mammals.
But there's a problem with arguing Jesus came about through cloning or parthenogenesis - he would have been born a girl. In the past few decades, science revealed that to be male you need a Y chromosome, and the only place you can get one is from a man.
''There's a big split over the Y chromosome issue,'' says Boston University theology professor Wesley Wildman. One thing Catholics and Protestants seem to agree on is that Jesus was fully human and male, so he must have carried the usual male quotient of DNA. It's not the Y chromosome he needed per se but a gene called SRY normally carried on the Y.
Occasionally this male-making gene gets moved off the Y, giving rise to an infertile XY woman. In a few cases men are found to have two X chromosomes, but such XX males turn out to have this critical fragment of the Y stuck on one of the other 22 chromosomes. That fragment of the Y has to come from a father.
Biology professor David Wilcox of Eastern University, a Christian college, said some aspects of reality may lie beyond the reach of science. ''Of course Jesus had DNA and a Y chromosome - and the source for half of that DNA [and the Y chromosome] would presumably be pure and simple miracle,'' he says.
Theology professor and ordained minister Ronald Cole-Turner said standard Christian thought attributes the virgin birth to God's intervention in the natural order, not a biological anomaly. ''It's not God's sperm . . . but God created something like a sperm and caused it to fertilize Mary's egg,'' he says.
Wildman says it's not as big a problem for Protestants like him to accept a non-virgin Mary as it is for Catholics who revere her. The Bible is ambiguous on the point, he says, since in the original Hebrew Mary is referred to as ''almah,'' a word that can mean virgin or young girl.
But a natural conception was problematic to early Christian thinkers, Wildman said, because St. Augustine and others believed original sin was passed on ''through the male via the loss of control associated with the male orgasm.''
That's why Catholic thinkers introduced the concept of immaculate conception, a term often misunderstood as the conception of Jesus, but which really refers to the conception of Mary herself. Her mother need not have been a virgin, but somehow God blocks the passage of original sin.
But for Jesus, a miraculous manufacture of genetic material would imply there's a sequence of genetic code designed by God himself - God's own approved DNA. That would have big implications for those who believe in the premise of The Da Vinci Code - that Jesus had children and his lineage continues to the present day.
''The bottom line for me: I think the virgin birth is a mistaken belief,'' Wildman says. ''I also think that this need have no impact whatsoever on Mary's and Jesus' moral and spiritual importance.''
A nonvirgin birth would, however, seem to raise the spiritual capital of sex.