World History One
Nature reports on a DNA study that seems to confirm that the people of Rapa Nui (aka Easter Island) had significant contacts with people of South American ancestry around the 14th Century CE, long before any Europeans beyond the Norse had visited either the Americas or the Pacific.
The likelihood had been suggested before: what about those (Asian) chicken bones found in South America or those (American) sweet potatoes on Rapa Nui? And it seems at least plausible that the Polynesians, having explored the whole Pacific Ocean, had not covered the last gap, bringing them to American coasts. But this seems the most persuasive evidence.
Apparently the same ancient DNA suggests that Rapa Nui never suffered a precontact over-population and collapse as previously hypothesized -- and taken up at length in Jared Diamond's Collapse.
World History Two
Serious history on a podcast? Sure. Listen to William Dalrymple describe on the Empire podcast how India practically colonized the Roman empire once Rome occupied Egypt and opened a Red Sea route for India-Rome sea trades. He argues persuasively that the value of products that India delivered to Rome in and after the time of Augustus Caesar was far larger than all the tribute Rome extracted from Gaul. All those lions, tigers, and elephants in the Colosseum? Just a minor byproduct of India's massive exports to Rome -- and of Rome's export of mucho gold to India in return.
Dalrymple's larger point is an argument that India's economic and cultural empire in early times has been seriously overshadowed by China's reputation for wealth and influence. And Rome was only one market for India; a much larger one existed in south-east Asia, which is why you can visit the sites of ancient Hindu and Buddhist monuments from Thailand and Java.
A key Dalrymple objective: to suggest a reassessment of the Silk Road story, which sometimes seems to presume that all ancient trade had to be overland rather than seaborne. -- and that China was therefore the source of all that was traded.
Besides the podcast chat, the full argument comes out in Dalrymple's new book The Golden Road, just published in the U.K. (reviewed here in the Guardian).