James Anderson (asst. professor of theology and philosophy at RTS-Charlotte) offers “twelve prima facie reasons why an evangelical view of the Bible commits one to the existence of Adam has a real historical individual. Go to the post to read his 12 reasons. Here’s the conclusion:
Taken together, these twelve points add up to a strong prima facie case for the traditional Christian view that Adam was a real historical individual. Any scholar who holds to the authority and inerrancy of Scripture, but denies this point, surely has a lot of explaining to do. If all we had to deal with were the first few chapters of Genesis, appeals to genre and other literary considerations might provide sufficient wiggle room. But the twelve observations above indicate that the historicity of Adam is a thread woven all the way through the Bible’s history, theology, and ethics. Pull out that thread and sooner or later the whole garment will unravel.
Update: Dr. Anderson responds to some objections here.