From Geoff Badley, Hedge End, Hampshire, UK
Greg Nuttgens thinks AI won't take over soon because it can't make a body for itself (Letters, 7 January). Perhaps. But we should remember that many life forms – possibly even DNA – started off as parasites. No parasite sets out to kill its host, either as an individual or a species, but it may change its host's health and behaviour. And, as with any organism, a parasite's basic aim is simple: to replicate.
