What happened to ancient civilizations? (READ BELOW)?

The ancient civilizations you list were destroyed. The Incan and Mayan civilizations were destroyed by the Spanish conquistadores in the 16th and 17th centuries. The Egyptian civilization was destroyed by the Persians in the 6th century BC.

If you are talking about the people who built the civilizations, they are still around. The Egyptian people became known as "Copts". They converted to Christianity in the 2nd century. You can find their communities in Egypt today. The Mayan people are still the majority in central America and they still speak the Mayan language. The movie Apocalypto was filmed in Mayan communities and many of the people in the movie are Mayans. The Incan people are still a majority in Peru, Columbia and Venezuela, although they speak Spanish rather than Incan. The current president of Venezuela, Hugo Chavez, is part Incan.

Incas and Mayas were conquered by the Spanish Conquistadors and the civilisations ended. The Egyptians of the Pharaohs was conquered by Alexander the Great and eventually a dynasty of Greek pharaohs ruled the Ptolomeys. In turn they were conquered by Rome and Egypt remained part of the Eastern Empire until conquered by the Islamic expansion of the 8th and 9th centuries

--The Egyptians were taken over by the Romans, and after being ruled by many different civilization were eventual given their independence from England following World War I in 1922.

-- The Inca, who's empire was located along the western shore of South America, were taken over by the Spanish Following the Inca Civil war in 1534. Francisco Pizarro was the Spanish commander who is responsible for conquering the Inca.

-- The Mayan peoples disappeared and left many of their cities. there are no signs of conquest or clues to why they left. This is one mystery that eludes historians to this day.

In my opinion;

Their civilizations became "fat and happy", which led to overconfidence, decline, and conquest by another power of simply assimilation into another culture that was more vibrant.

I hope this is helpful.

Egypt didn't go anywhere as far as I know... haha