How can I understand the rise of the Egyptians as a race in the Old Testament? The Old Testament states that God created the world and God created man.  We see the lineage of Adam and Eve, to Abraham, and so forth while the Hebrew nation is created.  Then, seemingly from left field, the Egyptians appear, and they are considered evil because they are worshiping multiple Gods and have enslaved the Hebrews, etc. This ultimately leads to the plague and the story of Moses leading the Hebrews out of Egypt.

I am struggling with how to state this question, but here it goes: If God created all mankind, how did nations such as the Egyptians end up so far off course?  Would they not have been descendants of Abraham as well?

This does not seem to be covered by the Old Testament (much like the gap in Jesus' early years in the New Testament), so I am perplexed.  It almost seems as though they evolved on a separate path.  Can anyone point me to resources that would fill this gap?  Or have I missed a critical passage in the Old Testament somewhere?
From a Biblical perspective, the Egyptians would have descended from Noah, but not from Abraham.  Genesis 10 is considered the "Table of Nations" in the Bible as it details how the sons of Noah began to populate the earth.  

The tower of Babel in Genesis 11 is also a very significant event.  God had commanded Noah (like He had Adam) to fill the earth.  The Tower of Babel was a direct act of disobedience by the people to not be scattered over the face of the whole earth.  God confused the language there in order to force mankind to obey Him and spread out across the whole earth.  The Egyptians were some of these people, no doubt.

The spreading out didn't totally resolve the issue, though, since now you had people all over the earth who had already rejected God, at least in part, at Babel.

Clarence Larkin has a very interesting chart detailing how the sons of Noah spread out over the earth.

So, there really isn' a gap at all.  It probably just isn't as explicit enough to make it obvious.