Last Night's Television - Mouth to Mouth, BBC3; Life, BBC1

Brine scene investigation

There are sound Darwinian reasons for supposing that the further one penetrates the depths of the oceans the more exhilarating the species and organic matter one discovers will be. This is not just because of the intrigue of unchartered waters, or those glorious moments when hitherto unobserved life passes from the sphere of the unknown to the known. Rather, it is because the further from the surface you go, and the further from the consoling provisions of air and land, the harder you must strive to survive. And in the grand sweep of Darwinian logic, that means evolving in crazier and more beautiful fashions.

That, at least, was the premise of this, the eighth episode of Life, the latest spectacular BBC series on the world beyond human civilisation. And in terms of sheer aesthetic majesty, the claim that this is "life as you've never seen it before" is unanswerable. The "Creatures of the Deep", as the episode was called, performed extraordinary feats to stay alive. There were fluorescent worms three metres long, giant urchins with harpoon-like tentacles and swarms of jellyfish that have no brain and no blood yet, through specially adapted light boxes and bodies capable of jet propulsion, are able to float, seemingly aimlessly, in their thousands, resisting predators and hunting prey with effortless ease.

Life down here can be excruciatingly slow, so in a series of charming sequences, the show's producers speeded up the footage to 500 times normal speed, creating a magical, cartoon-like effect eerily reminiscent of the early work of the film director Peter Jackson. Together with the soundtrack, by turns spooky and euphoric, the magical underworld was thereby given an air of fantasy, the stuff of children's literature through the ages.

Yet the feeling that this environment is incredible was only occasionally interspersed with the narrative style familiar to all such BBC productions, in which David Attenborough's austere vowels illuminate the characters on screen. Attenborough's voice, though peerlessly authoritative and by now even soothing, punctures the element of fantasy in a way that can grate. Of course, it is enlightening to be told what is in front of one's eyes, but veteran viewers of this genre occasionally want to marvel at the screen without the addition of a human voice, especially when there is a kind of creeping anthropomorphism to the commentary.

Take the sequence in which a small male squid adopted the neon colours of a female so as to fool a giant male into thinking he was being courted, and so impregnate the female over whom the bigger male was hovering. The commentary was full of references to the "young pretender", the "would-be prince", and so on. It was a delicious, arresting sequence, but described in the language of the royal court it lost something of its mystery, and became instead wearily overfamiliar. Other sequences were by the same method touched with farce. One massive jellyfish popped up on screen with a white exterior and a powerful yellow centre. "Here, the fried-egg jellyfish appears," Attenborough said, and you thought he must be joking, but he wasn't. Come of it, David. It looked more poached than fried anyway.

In a manner popularised by that earlier, more thematically focused, and better series, Planet Earth, the last 10 minutes, "Life on Location", give an insight into the eccentric characters behind the camera. This week, the Life team drilled a massive hole in 8ft of Antarctic ice and built a temporary hut on top of it, in which they planned to live for a month; then they sank a boat in the Caribbean – yes, sank a boat – for the benefit of approximately 10 seconds of footage, to show how coral reefs (which like sunken boats) start up.

I'm afraid it is impossible to watch this stuff without thinking of how astronomical the budget for such programming must be, and feeling a twinge of (delete as needed) pride/hatred when one thinks of having slightly paid for it all. But I have a solution, neither original nor particularly radical, which will make funding Life, and defending the BBC, infinitely easier. Scrap BBC3.

One of the more useful dichotomies of the age must be the brilliance of BBC4 and the tawdriness of BBC3, the best and worst of television respectively. I had thought Two Pints of Lager and a Packet of Crisps was the worst show on television, but it may be surpassed by Mouth to Mouth, of which there was a double bill. This show feature several decent actors reading an appalling script, which they relate directly to the camera (making you, the viewer, the second mouth – it's mouth to mouth, geddit?). In episode three last night, our hero revealed the trauma of being a lower-middle-class man negotiating episodes of football and erectile dysfunction. We had snapshot messages from friends of his, all of whom are afflicted with similarly vacuous dilemmas. It was like the film Human Traffic minus the clever observations. How on earth this sort of television can be defended, in the interest of promoting new talent, or advancing the cause of British scriptwriting and comedy, I will never know.