Cultural evolution, not the brain, drives language development

I love it when general theories are debunked!

From the BBC:

Modern phylogenetics studies look at variations in animals that are known to be related, and from those can work out when specific structures evolved.

For their studies, the team studied the characteristics of word order in four language families: Indo-European, Uto-Aztec, Bantu and Austronesian.

They considered whether what we call prepositions occur before or after a noun ("in the boat" versus "the boat in") and how the word order of subject and object work out in either case ("I put the dog in the boat" versus "I the dog put the canoe in").

The method starts by making use of well-established linguistic data on words and grammar within these language families, and building "family trees" of those languages.

"Once we have those trees we look at distribution of these different word order features over the descendant languages, and build evolutionary models for what's most likely to produce the diversity that we observe in the world," Dr Dunn said.
Pea plants in a greenhouse The methods use inference in a similar way to Mendel's studies of pea plants

The models revealed that while different language structures in the family tree could be seen to evolve along the branches, just how and when they evolved depended on which branch they were on.

"We show that each of these language families evolves according to its own set of rules, not according to a universal set of rules," Dr Dunn explained.

The Economist's take on the subject:
http://www.economist.com/node/18557572