Since Evolution became the dominant religion in the scientific community, many Christians have taken to changing their interpretation of Genesis. Some resort to utterly denying the existence of Adam and Eve, but given how difficult that is, others tend to accept their existence, but deny their attributes. Some, for example, claim that there is nothing that says Adam and Eve were the first, nor the only people on the Earth. Instead, they were one couple of many humans, and were merely representatives of the human race, much like the Old Testament's focus on Israel doesn't mean there were no Australians.
This causes just as many theological problems as denying their existence, but the thing is, it's not even true. The Bible does claim, as seen below, that 100% of the human race are descended from Adam and Eve.
Looking first at how Eve got her name, it's impossible to deny that Eve is not the mother of all the living. Mostly because it says she was the mother of all the living... What does this mean, exactly? The only sensible interpretation is that Eve was, quite literally, the mother of all the living. If it's human, and it's neither Adam nor Eve, she is the mother of it.
Then Luke goes on to block any possible interpretations about a spiritual element when he says God made all nations on the Earth from "one blood". In other words, no matter your skin tone, no matter your body structure, no matter your native language, no matter what continent you live on, you have the same blood flowing through you as every other human being on the Earth.
"That just means we're all united under Christ". Really? Even the nations which, as of yet, have not received the Gospel? One tribe is so hostile that every attempt to contact them has resulted in a barrage of spears and arrows. They don't know the Gospel.
No matter which way you cut the cake, the fact is the Bible makes it quite clear that Adam and Eve were the first human beings, created on the sixth day of history, and that we are all descended from them.
I have deliberately excluded scientific evidence for this fact. The reason for this is because I want to keep the focus entirely on the scripture. Where does your faith lie? If you must use "science" to reinterpret the Bible, your faith is not in God, but in man's ever-changing, sometimes deceptive interpretation of the natural world. With only God's word, could you ever have come to the conclusion that Adam and Eve were fictional, or that they were merely primitive descendants of ape-like creatures? In the slightly edited words of Joshua, "if it seems unintelligent to you to serve the LORD, choose for yourselves this day whom you will serve, whether the gods of theistic Evolution which the pagans preached, or the modern Evolutionary fairy tales which the atheists preach. But as for me and my house, we will serve the LORD.”