Stephen Fry is an intelligent , charismatic and interesting man, however, largely illiterate when it comes to science. This faecal fantasy (and a couple of other pop-science shows he's leant his gravitas to recently) show either he is being poorly advised by his agent and/or young husband or he has lost any sense of self reflection - if you hold a position of omniscience in the psyche of the public like Mr Fry you must be able to judge the veracity of what you're being asked to read as fact. Otherwise you're just misinforming the public as well as taking work away from qualified presenters innit. Do some documentaries on literature or philosophy or summit else you're qualified in Ste.
Most of what is in this show is very broad stroke and pretty uninteresting if you've read a book or been to a museum in the last 20 years. Some of is contradictory even within the same episode and some proposals are a real stretch (although in science all hypothesis are just that, I suppose) Thankfully there are a couple of reasonable experts (Dr S Maidment for example) who refer to the fossil record when answering the rather ignorant and childlike questions they've been compelled to address and who do make it clear theories are theories - even good ones - in their responses.
Basically avoid at all costs, unless you've a very small child who's not old enough to read but you need to distract for a few minutes, whilst you finish dinner/clean to loo/reply to emails.