It's more than 35 years since Welsh writer Elaine Morgan took America by storm with her book The Descent of Woman. It was named Book of the Month and launched her on a coast-to-coast tour of TV and radio studios as a spokeswoman for the feminist cause. In March 2008, the month that her latest book was published, she recalled the heady days of 1972 in two programmes on BBC Radio Wales.

Echoing the name of the major TV series she wrote about David Lloyd George, The Life and Times of Elaine Morgan told the remarkable story of how the daughter of an unemployed miner won a place at Oxford University, became a top television dramatist and challenged the scientific establishment with a radical theory of human evolution.

James Stewart, who presented the programmes, said: "She has a very dry sense of humour and some very funny stories to tell - about her family and her career. Highlights for me are her story of her father as an amateur dentist, her life with a rabbit catcher and how the Americans thought she was bringing a 'toy boy' on her promotional tour!'

James first met Elaine in 1986, when he interviewed her late husband Morien about his experiences in the International Brigades during the Spanish Civil War.

Born and raised in Hopkinstown, near Pontypridd, Elaine has lived for many years in Mountain Ash, near Aberdare. It was there that she wrote the scripts for many of her TV drama adaptations, including The Life and Times of Lloyd George, Richard Llewellyn's How Green Was My Valley, and the Bafta-award-winning Testament of Youth based on the memoirs of Vera Brittain.

Her new book - The Naked Darwinist - is the latest in a series in which she has developed the theme outlined in The Descent of Woman. Almost single-handedly, Elaine Morgan has promoted and developed the theory that humans are descended from an ape ancestor which moved from the trees to live in and around water. She challenges the scientific establishment to engage with the 'aquatic ape theory'.

The zoologist Desmond Morris - author of The Naked Ape - told Radio Wales there was now a long list of specific points to support the theory and he believes this phase of human development is 'highly likely'. He adds that "if not for Elaine Morgan, the aquatic ape hypothesis might have been forgotten".