Murray will present a new music show from Monday to Thursdays from 10pm, which will focus on playing a wider variety of specialist tastes for the youth market.
The corporation will also unveil a four-nights-a-week show called 'In New Music We Trust', which will be hosted by a range of Radio 1 presenters, with full details yet to be announced.
Bowman, who co-hosts the 1pm-4pm weekday show with Murray, is being kept in that timeslot before the Scott Mills drivetime programme, reflecting the station's confidence in her ability to pull in listeners.
Bowman said: "Exciting times ahead, obviously sad that it's the end of our mini era, but ecstatic at the prospect of having my own daytime show on Radio 1."
In other changes, Annie Mac is to host an as-yet-untitled new show the BBC is describing as "by the audience for the audience". There will also be a multi-genre show that will feature new DJs, and two new signings, Eddie Halliwell, who will be playing club records, and DJ-team Trophy Twins, who will occupy the early hours weekend slot.
Ian Parkinson, head of specialist music and speech at Radio 1, said: "It's important for the schedule to keep evolving to keep pace with the musical passions of our young audience, which is why we've made these changes.
"Colin brings with him a wealth of specialist knowledge as well as consummate skills as a broadcaster and it's great to be able to give new talent like Eddie Halliwell and the Trophy Twins their own shows."
Radio 1 has also announced that Chris Coco and Fergie are to leave the airwaves in September, but will continue to put together the 'Essential Mixes' for the station.
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