Indo-Anatolian? Reaction to Harvard's Southern Arc paper

A new genetics paper 'The genetic history of the Southern Arc: A bridge between West Asia and Europe' by Lazaridis et al boldly endorses a controversial theory for the origin of the Indo-European languages - that they were first spoken south of the Caucasus and were brought to the Yamnaya and related peoples who then spread them, rather being autochthonous to the region.

In this impromptu and informal live stream I shall look at some of the claims within and offer my own takes in response.