I’ll be talking at the NZ Phylogenetics Meeting this week on Horizontal transmission and cultural phylogenies:

Phylogenetic tree thinking is beginning to revolutionise studies of linguistic and cultural evolution. However, linguistic and cultural traits are easily transmitted horizontally (“borrowed”) between cultures. Indeed, well over 95% of the words in the Oxford English Dictionary aren’t English. A loud and persistent debate has centered around the issue of borrowing and whether it invalidates cultural phylogenies or not. Here, we use a natural model of linguistic evolution to simulate borrowing between languages. The results show that tree topologies constructed with Bayesian phylogenetic methods are relatively robust to the effects of realistic levels of borrowing. Inferences about time depth are slightly less robust.