You might be a little hard on the Africans. First, you can’t separate the Egyptian Civilization from Africa, particularly because it seems the Egyptians came in large measure from the Sahara as it dried out. Also, you have the Nubian, Ethiopian, Kushan and West African Cultures. The Nok, Bantu, Ghanan and Benin cultures in West Africa began about 900 BC growing from agricultural settlements. The Sahara was their “ocean”. The impact of the spread of Islam which leveled cultures out to a Muslim pattern certainly had its impact in Africa and in the trade routes moving gold, copper, ivory, etc. North across the Sahara to the Mediterranean. European colonialism was a further blow to African civilizations already savaged by Islam and an expanded slave trade.
I agree. And this doesn’t even take into account Phoenician/Carthaginian colonies (”Periplus of Hanno”) and circumnavigation of Africa (Herodotus); the Romans, who relied on very deep trade routes to supply their games with exotic animals (for that matter, the Romans depicted what is clearly an Orangutan, which is only found on Borneo SE of Asia); and Hindus and Tamil at least as long ago as classical times.