Aware of their adoption, they independently took DNA tests for separate reasons, unaware that they would discover an identical twin.

Source: https://collider.com/the-amazing-race-secrets/

Do I have an identical twin?'

Source: https://www.aceshowbiz.com/news/view/00206496.html

“Her identical twin, Nancy, was also on a diet containing the same amount of calories, nutrients, fat, sugar and fibre - but she was consuming raw or low-processed foods,”

Source: https://www.huffingtonpost.co.uk/entry/ultra-processed-foods_uk_647ef468e4b0047ed7832866

Meanwhile, Ross and his identical twin brother Hugo hold world records for being part of the youngest four-man crew to row the Atlantic.

Source: https://www.dailymail.co.uk/tvshowbiz/article-12350645/Ascot-TV-presenter-Rosie-Tapner-engaged-long-term-partner-Ross-Turner-announces-news-sweet-Instagram-post.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

The 'Chrissy's Court' star has taken a DNA test and freaked out when discovering an 'identical twin' symbol on a DNA map before eventually finding out who her mystery twin is.

Source: https://www.aceshowbiz.com/news/view/00206496.html

The Mummy star Rachel Weisz plays a pair of identical twin OBGYNs in first look images from Prime Video’s gender-swapped Dead Ringers TV show remake.

Source: https://screenrant.com/dead-ringers-show-images-twins-gender-flip/