THE Adam was a direct creation by God after the creation of other forms of life, including different races of men. Adam was mentioned as he was the progenitor from which Christ would come. IOW, the Bible is the story of the tribes......plural mind you, of Israel. There were other people for Cain to go to after he murdered his brother. Under my theory and belief, those who would give birth to Abraham, Isaac and Jacob, came from THE Adam. Other people on this Earth were created between “IN THE BEGINNING and THE Adam.” Just as if I were to tell the story of ME, it would start at my birth...to go back to my parents, or grandparents would lend light only peripheraly.
There is one big biblical problem with God creating Adam separately from different races of men. Romans 5:12 says “Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:”
Sin came into the world by Adam, and therefore all have sinned. But if God created many different “adams” then we are not all descended from the one Adam, are not all sinners, and don’t all need Christ.
Genesis 1 talks about creation of adam. If this passage is referring to God creating various races of men, then why does Genesis 2:5 state “there was not a man [adam] to till the ground.”?
Genesis 1 and 2 are just different naratives of the same event.
The Bible doesn’t mention any other people that Cain went to after the murder of Abel. It does say that he went to live in the land of Nod. He took his wife with him, which of course would have also been his sister, as there wasn’t anyone else around to marry.
The tribes of Israel happen much later, and really have nothing to do with creation.