Charles Darwin once wrote to his doctor: 'We are a wretched family and ought to be exterminated.'
The great scientist was worried that his marriage to his cousin, Emma, had created inbred children who were suffering ill-health.
Three years earlier, in 1859, Darwin had published On The Origin Of Species, his revolutionary treatise on evolution, and he knew the importance of passing on strong genes.
Thankfully, his family were living proof of his theory of the 'survival of the fittest' and they overcame repeated bouts of scarlet fever.
Inspired by the famous 'tree of life' sketch that Darwin drew in his notebooks to help explain the origins of life, we decided - to mark the 200th anniversary of his birth - to trace the father of evolution's own family tree to discover what his descendants are doing today.
Charles and Emma Darwin had ten children, of whom seven survived to adulthood. Although only three provided Darwin with grandchildren, subsequent generations have - not unsurprisingly - shown a marked aptitude for success, albeit not always in conventional ways.
Of Darwin's five sons, three received knighthoods - for services to science, botany and engineering. Others linked to his family included the composer Ralph Vaughan Williams and the novelist E. M. Forster.
Today, there are an estimated 100 living descendants of Darwin. They include a novelist, a screenwriter, an expert in exotic tomatoes and a church deacon with views very close to the creationist beliefs that the world was created in six days - which Darwin refuted. Distant relations include politicians Tony Benn and his Cabinet minister son, Hilary.
'Children are one's greatest happiness, ' Darwin wrote in February 1862. He would not have been disappointed by his own legacy - but he might have been a little surprised...
Descendants 1 and 2: Sarah Darwin and Skandar Keynes
1. The botanist
Sarah Darwin, 44. Great-great-granddaughter
Aged nine, she began a long-lasting fascination with plants. After graduating with a first-class degree in botany from Reading University, she joined the Natural History Museum and, like Darwin, has become an expert on the Galapagos Islands, specialising in the unique Galapagos tomato. She jokes: 'I think there is a family resemblance, though I don't think he necessarily looked like me.'
2. The teen actor
Skandar Keynes, 17. Great-great-great-grandson
Former school friend of Harry Potter actor Daniel Radcliffe. Aged 14, he landed the role of Edmund Pevensie in the blockbuster The Chronicles Of Narnia: The Lion, The Witch And The Wardrobe. Apart from Darwin, he can also claim the economist John Maynard Keynes, philosopher David Hume, politician Tony Benn and King Edward I within his family tree.
