Nearly 100 years after his death, a monument has been unveiled to commemorate Alfred Russel Wallace, co-discoverer of natural selection - the process that drives the evolution of life on Earth.
Alfred's grandson, Richard Wallace, unveiled the monument near Usk, Wales, outside the church where Alfred Wallace was baptised and close to the cottage where he was born in January 1823.
The monument is made from 350-million-year-old limestone and has fossils on its surface - something Wallace would have liked as he had an interest in fossils from an early age.
Although he is not a household name, Alfred Russel Wallace was one of the most famous scientists in the world when he died in 1913 aged 90.
During his long life he wrote about 700 articles and 20 books on a wide variety of subjects, making many important contributions to the fields of biology, geography, geology and anthropology. His best known books are Darwinism, The Geographical Distribution of Animals, and his famous travelogue The Malay Archipelago which has not been out of print since it was first published in 1869.
Wallace was one of the most prolific collectors of natural history specimens of all time, and in 2005 an important part of his personal insect collection from southeast Asia was discovered in his grandson's attic. Unfortunately the specimens had been badly damaged by pests, but have since been painstakingly restored by George Beccaloni, insect expert at the Natural History Museum.
Evolution by natural selection can be explained by the fact that the fittest individuals of a species are more likely to survive and reproduce and therefore pass their advantageous characteristics to their offspring. This ground-breaking theory changed the way we understand the natural world, and ourselves.
The idea of natural selection as the mechanism of evolutionary change occurred suddenly to Wallace while he was suffering from a fever on the remote Indonesian island of Halmahera in February 1858. Wallace wrote down his thoughts and sent them to fellow naturalist Charles Darwin whom he knew was interested in this topic.
Unknown to Wallace, Darwin had come up with the same theory of natural selection about 20 years earlier, but had been procrastinating about publishing the idea. Darwin was therefore horrified when he received Wallace's letter, and appealed to his friends the geologist Charles Lyell and the botanist Joseph Hooker for advice on what to do.
As the well-known story goes, Lyell and Hooker decided to present Wallace's essay (without first asking his permission), along with some unpublished fragments from Darwin's writings on the subject, to a meeting of the Linnaean Society on 1 July 1858.
These documents were later published in the society's journal as the article On the Tendency of Species to Form Varieties and On the Perpetuation of Varieties and Species by Natural Means of Selection.
Even though Darwin's book the On The Origin of Species was not published until a year later in 1859, most people still believe it was the book where the theory was first proposed.
'During Wallace's lifetime the theory of natural selection was widely known as the 'Darwin-Wallace theory'' explains George Beccaloni, 'but after his death his name slipped into relative obscurity for a variety of complex reasons.'
'The Alfred Russel Wallace Memorial Fund is trying hard to make more people (scientists included!) aware, not only of Wallace's role as the co-discoverer of natural selection, but also of his many other important and enduring contributions to biology and a wide variety of other disciplines.'
The Wallace monument rock was donated by Hanson Aggregates from a quarry near Bridgend and two granite plaques were produced by the Welsh company Mossfords. The monument was paid for by the Alfred Wallace Memorial Fund, which Natural History Museum scientists George and Janet Beccaloni set up in 1999 in order to restore and preserve Wallace's neglected grave in Broadstone, Dorset.