The great-great-granddaughter of Charles Darwin has set sail from Devon to recreate the journey which inspired his theory of evolution.
Darwin's original five-year voyage of discovery on HMS Beagle began in 1831 from Plymouth Sound.
Biologist and botanist Sarah Darwin, 44, will retrace her forefather's footsteps.
"We're going in his wake, so to speak, visiting pretty much everywhere he went," Ms Darwin said.
Darwin's book On the Origin of Species by Means of Natural Selection was published in 1859.
Ms Darwin said she had been looking forward to the journey for many months, not only to see many of the things which influenced her great-great-grandfather, but also to establish how relevant his findings are for the planet's future.
Darwin's historic voyage on HMS Beagle took five years
"We'll be looking at the condition of the rain forests and oceans and air quality," she said.
The voyage will be made aboard the Dutch Clipper Staad Amsterdam. The sailing ship was built in 2000 to recreate a mid-19th century clipper, but at 250ft (76m) it is about double the length of Darwin's Beagle.
There is a laboratory on board where visiting scientists will undertake a number of experiments.
Sarah Darwin will be joined for part of the eight-month voyage by her husband, Dr Johannes Vogel, and her two sons Leo and Josiah, aged six and four.
Dr Vogel is the keeper of botany at the Natural History Museum in London.
Sarah Darwin speaks to BBC News about recreating the voyage made by her great-great-grandfather Charles
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