A historian and consultant for TV series Who Do You Think You Are? spoke to the Dunmow U3A about what happens behind the scenes of the show.
Dr Nick Barratt spoke to members last month about the purpose of the show, which features celebrities delving into the lives of their ancestors.
Group spokesman, Jennifer Versey, said: "He said the show is about the social history of our country by telling the stories of our ancestors; and in a way that interests everyone.
"He explained that in the digital age, people rarely write letters anymore, photographs may be shared online, but many will get lost over time. Many evidence sources used now, such as written reports and letters, may not be there as evidence in the future.
The U3A's next talk will be on October 23, from 2pm, at Foakes Hall, when Peter Layzell will speak about his life as a rural sergeant.
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