Tenthmedieval this morning has a rather wonderful piece on some of the less thinking coverage of the discovery of a rather corroded Chinese coin in East Africa.
I think it's fair to say that the areas that are now Somalia, Kenya and so on have always been connected as long as people have sailed ships - there's evidence of Hellenistic and Roman contacts to say the least. And these trade networks persist across political and religious changes because they are useful. So it's not surprising that the Chinese followed existing trade routes and reached east Africa, just in the same way that Chinese merchants followed the sea cucumber trade and probably ended up in Arnhem land - certainly rock art paintings show their Makassan trading partners from what is now Sulawesi did.
And if we were to find a record of a kangaroo in China it might be surprising, but not inexplicable.
I increasingly find the connections between cultures fascinating. And why certain trade routes developed they way they did, often due to geography - ocean currents, mountain ranges, availability of resources etc.
There is a tendency in western society to think that we discovered them and that they occupied separate little compartments.
They didn't. The Assyrians traded with India via Dubai and Bahrain. The Greeks went to Afghanistan on the back of Alexander's conquest of Persia and carved some rather nice portraits of the Buddha in very Greek looking robes. Chinese traders and merchants expanded over large parts of south east Asia. And of course people met and traded. It's why the Staffordshire hoard contains jewels originating from India. Not that an AngloSaxon warrior went to India (although one might) More likely it was traded via Byzantium and Dubai (or via Somalia and Egypt).
Renaissance Europe 'discovered' South East Asia and Africa due to trying to cut out the middlemen in the spice trade, and in the course of doing that came across a range of societies previously unknown to them. These societies were of course not unknown to each other.
And this is different from the situation in the Americas where the Amerindian civilisations developed independently, or Australia, which while known to Indonesian fishermen, was viewed as being hostile and valueless. If one of these fishermen had known there were opals out there in the desert, history might have been different