First edition of Charles Darwin's classic work sells for almost £100,000

The book, which was one of only 1,250 copies published in the first print run on November 24 1859, was bought at a sale at Bonhams in London by an American bidder for £98,500, double its estimated value.

The copy, which was signed by one of Darwin's closest friends botanist Joseph Dalton Hooker, had originally cost only 15 shillings – or 75p in modern money – and had been expected to sell for between £50,000 and £70,000.

It was considered even more valuable because it was signed by one of Darwin's closest friends - the distinguished botanist and explorer Joseph Dalton Hooker.

Mr Hooker presented the book to his uncle, Norfolk parson, the Rev John Gunn, and it is signed "To Revd Gunn,from his affect. nephew, JDH , Kew, Dec 5/59."

Bonhams described the book as "a magnificent association copy of the first edition of the most important biological book ever".

On the association between Darwin and Mr Hooker, Bonhams said: "Joseph Hooker was one of Darwin's closest friends: their correspondence comprising some 1,400 letters. Their close personal relations were cemented in 1851 when Hooker married Frances, eldest daughter of John Stevens Henslow, the Cambridge professor of botany who had inspired Darwin when he had arrived at the university in 1828."

Darwin was born at The Mount, Shrewsbury, on February 12, 1809, and was the fifth child and second son of Robert Waring Darwin, Shrewsbury's principal physician.

At Sotheby's in New York on April 26, 2005, a page from the original manuscript of On The Origin Of Species - in Darwin's own handwriting - sold for £143,164. Equivalent to £900 per word, making it the most valuable piece of writing by any Shropshire-born author.

At the same auction, a "near fine" first edition copy of On The Origin Of Species sold for £69,070.