second floor

economist.com reports on new research that suggests biological evolution and linguistic evolution behave similarly:

Languages are formed not, it seems, by a gradual drifting apart of two groups who no longer talk to each other, but by violent rupture. Around a third of the vocabulary differences between modern Bantu speakers arose this way, around a fifth of the differences between speakers of Indo-European languages, and around a tenth of the Austronesians. That compares with around a fifth for biological species.

All this suggests that the formation of both languages and species is an active process. For species, adaptations to novel environments and the need to avoid crossbreeding with those on the other side of the split are both plausible hypotheses. For languages, the explanation may be a cultural rather than biological need to distinguish populations.