Rachel Riley replaced on Countdown by YouTube star in major show shake up

RACHEL Riley has been temporarily replaced on Countdown - by a YouTube star.
The Channel 4 words and numbers show will undergo its biggest shakeup in recent years.
Rachel, 39, will temporarily step away from the daytime hit to focus on another project.
Countdown producers have drafted in mathematician Dr Tom Crawford as her replacement.
Dr Crawford appears more than qualified for the role, having obtained a PhD in Fluid Dynamics from the University of Cambridge.
The YouTuber also completed a maths degree from the University of Oxford.
Speaking about joining the show, he said: "COUNTDOWN. Still can’t believe this happened, but you will now be able to watch me attempting to do maths live on television for the next 3 weeks, starting Monday at 2:10pm on @channel4. @rachelrileyrr - and her unparalleled arithmetic skills - are irreplaceable, but with @mrcolinmurray and @susiedent by my side, we’ll do our very best to keep you entertained for the next few weeks.
"Long live daytime television!!"
Rachel joined Countdown in 2009, having taken over from Carol Vorderman who departed the year previous.
Countdown has aired over 8,000 episodes since its launch in 1982 with Richard Whiteley, Des Lynam, Des O'Connor, Jeff Stelling, Nick Hewer and Anne Robinson all having stints as hosts.
Colin Murray took over as host of the long-running series in 2022, having become a fan-favourite with viewers.
Last year The Sun told how mum-of-two Rachel was forced to draft in security over death threats.
She previously said she has been left ‘shaking with fear’ after being vocal in support of the Jewish community amid the Israel Palestine war.
She first hired the security in October of last year and still believes she needs support after ongoing trolling online.
An insider said: “It’s been a really difficult time for Rachel and she is determined to keep being a voice for the community.
“The security has given her that extra confidence. It’s not ideal, but she feels like it’s important.”
Since launching in 1982, Channel 4 game show Countdown has become a staple of daytime telly. There have been several presenters throughout the show's long history. Let's take a look back at who has hosted the iconic show.