From David Beck
Historical linguists have been borrowing techniques from biological taxonomy, including models based on genetics, for years (7 September, p 32). The results are interesting, but biological organisms differ from languages in at least one important way: complex organisms diverge genetically over time and reach a point where exchange of genetic material is all but impossible.
Languages never reach such a stage. No matter how distantly related, they can and do exchange words, sounds and grammatical devices. Microorganisms might be a better model, as genetic exchange is more common even when distantly related.
Edmonton, Alberta, Canada
