Wanted: insomniac, talkative dinosaur. Female preferred... The search is on for the new David Letterman

But America's late-night round-up is showing its age

Ellen DeGeneres

Like every area of American life, the late-night TV schedule has been dominated by straight white men. Little wonder, then, that as veteran host David Letterman prepares to retire from The Late Show on CBS in 2015, many hope that a woman will replace him.

It almost happened once before. In the 1980s, comedian Joan Rivers became a regular guest host for her mentor Johnny Carson on NBC's The Tonight Show. But any aspirations she had of taking his place were dashed when she moved to Fox in 1986 to host a short-lived rival show – without warning Carson, who never spoke to her again. She was banned from The Tonight Show until seven weeks ago, when new host Jimmy Fallon invited her to appear.

At 80, even the indomitable Rivers might balk at the gruelling schedule of a late-night host, fronting an hour-long show, Monday to Friday from 11.35pm. But several other candidates have been suggested.

Ellen DeGeneres, at 56, has won 36 Daytime Emmy awards in her 10 years at the helm of a daytime talk show and plaudits for twice hosting the Oscars. Chelsea Handler, who since 2007 has hosted her own talk show Chelsea Lately on the cable channel E! is another plausible replacement, not least because she recently announced her intention to leave E! when her contract expires towards the end of 2014.

There is a growing lobby on behalf of comedian Amy Schumer, who impressed in an appearance on Letterman last week to promote her sketch show, Inside Amy Schumer. She might, however, be more interested in a movie career: she is set to star in director Judd Apatow's next film, Trainwreck.

Chelsea Handler

Inevitably, front-runners in the race to replace Letterman are two more straight white men: Comedy Central's Jon Stewart and Stephen Colbert, the hosts of The Daily Show and The Colbert Report respectively. Both now attract a greater audience share in the crucial 18 to 49 age demographic than their broadcast network rivals, including The Tonight Show and The Late Show. With a salary of between $25m and $30m, Stewart is the highest-paid host on US television, and is said to have little incentive to leave his current job.

Amy Schumer

For Colbert, though, The Late Show would be a grand stage on which to finally shed the fake, conservative "Stephen Colbert" persona he has maintained until now. He is thought to be CBS's preferred replacement for Letterman, and is said to be interested in the role.

The Hollywood Reporter says that CBS approached John Oliver from The Daily Show about taking over the nightly, post-Letterman 12.35pm slot currently occupied by fellow Briton, Craig Ferguson. Oliver went instead to HBO, to present a new weekly show on Sunday nights.

Joan Rivers

The new Late Show host will hold considerably less cultural sway than when Letterman and his long-time rival Jay Leno took up their posts in the early 1990s. Late-night television is, arguably, a fossil from a prehistoric era, when audiences had only a handful of broadcast networks to choose from, and could only watch television at the time it was broadcast. Letterman and Leno are simply its surviving dinosaurs, dressed in denim jeans.

Fallon and Jimmy Kimmel, who hosts Jimmy Kimmel Live! on ABC at 11.35pm – have tweaked the late-night format sufficiently to account for the internet age, ensuring that their comedy and musical skits have viral potential. But why bother to update the late-night format, when the form itself is an anachronism?