Who Do You Think You Are? (BBC1, 9pm)

IN a first for the series, two related celebrities join forces to investigate their family tree. Comedian and actor Jack Whitehall and his father, occasional double-act partner

and talk show co-host Michael team up to look into their past. They learn about a tragedy that left Michael’s grandfather an orphan and follow their lineage back to Wales in the 1830s, where they find out about their Tory ancestor and his role fighting against the Chartist political and social reform movement.

The Conjoined Twins: An Impossible Decision (BBC2, 9pm)
CONJOINED twins Marieme and Ndeye have separate hearts and lungs, but Marieme’s heart is very weak and her life expectancy is poor. If she dies, her stronger sister will die with her. As the girls’ health deteriorates, their father Ibrahima and staff at Great Ormond Street Hospital are forced to decide whether a separation should be considered.

The Secret World of Your Rubbish (Channel 5, 9pm)
THIS new fly-on-the-wall documentary series follows people around the UK working in waste disposal and management as they clear up after us, day in, day out. The first episode features father and son Richard and Joe Crapper, the owners of a landfill site in Wiltshire. Plus, we meet London refuse collector Tamara, who reveals the difficulty of dealing with contaminated recycling.

Long Lost Family: What Happened Next (STV, 9pm)
DAVINA McCall and Nicky Campbell follow the stories of three families facing challenges building new relationships. Brenda Rhensius’s daughter Joanne has struggled because of the loyalty she feels towards her adoptive mother, while Spencer Brown and his sister Margot have been gradually trying to bring their worlds together. The third reunion was not originally shown and it is only now that Hazel Stubbs Races and her son Kenneth feel ready to share their experience.