How could the human race descend from a metaphor?

During an interview for a Roman Catholic newspaper in Ireland, the reporter told Ken Ham that a person of faith can believe in millions of years. The reporter started explaining that Genesis is a metaphor. So Ken asked him, "Does that make you a relative of a metaphor?" He pointed out to the reporter that the Bible lists the genealogy of Jesus Christ all the way back to Adam.

Then Ken asked, "When did the real people stop and the metaphors begin?" The reporter responded, "Well, the late pope said you could believe in evolution as long as man and woman were created with souls."

Ken went on to tell him about how Eve was made from Adam, and they were one flesh. This formed the basis of marriage, just as Jesus taught. If Adam and Eve came from animals, as evolution would have us believe, the whole doctrine of marriage is destroyed.

But not only marriage; all biblical doctrines, including the gospel, are based in Genesis. If Genesis is a metaphor, then our doctrines and the gospel would be meaningless.