Chapter 2 of Genesis tells how "God formed the man of dust from the ground and breathed into his nostrils the breath of life, and the man became a living creature." Later in the chapter God makes Eve out of Adam. Unless we see this chapter as metaphor rather than history, the biblical account is incompatible with the idea that Adam and Eve each had two parents plus some beneficial mutations.
Theistic evolutionists logically have to discount other parts of the Bible as well. It's not just that when we de-historicize parts it's hard to stop. (Were Noah, Abraham, and Moses also metaphors?) We also have to discredit Paul the apostle, who cited early Genesis as fact (see Romans 5, 1 Corinthians 11 and 15, and 1 Timothy 2).
For that matter, Jesus also saw it that way (Matthew 23, Luke 11). Those who say, "God merely used evolution to bring about the results He desired," may think they're avoiding arguments, but they are either relinquishing what's crucial—biblical inerrancy—or redefining chunks of Scripture as creative writing and literary appreciation rather than history.
Should we hug evolution to further evangelism? Theologian Wayne Grudem has it right: "Theistic evolutionists tell us that Christians can surrender to this massive attack on the Christian faith and safely, inoffensively, tack on God... To put it in terms of an equation, when atheists assure us that matter + evolution + 0 = all living things, and then theistic evolutionists answer, no, that matter + evolution + God = all living things, it will not take long for unbelievers to conclude that, therefore, God = 0." Again, let me stress that many theistic evolutionists are honorable individuals. Some think the evidence against macro-evolution is weak. Others think we must bow to evolution or bow out of academic and media summit conferences. I don't think that's inevitable, but if it happens: For such a time as this we must learn to trust God to change hearts without our having to back away from the Bible.