Egypt Revisited--More Evidence for the Case of Nubia Developing egypt

In the book, EGYPT REVISITED, edited by Ivan Van Sertima, there is a preponderance of evidence that Nubia influenced--if not developed Egypt and that is how the First Dynasty started off as a fully functioning institution. Nubia had a Pharaoh government in place before Egypt, many of the Egyptian gods were first worshiped in Nubia, and Nubia already had developed pyramids.

Additional research in other books shows that Nubia had mining and advanced pottery techniques in place before Egypt.

But--there is also evidence that Egypt may have developed segments of its culture independently. This brings a new question: If parts of Egypt developed independently, why couldn't the entire First Dynasty develop independently?