Darwin Day is a global celebration of science and reason held on or around February 12, the birthday anniversary of evolutionary biologist Charles Darwin.
2009 marks the 200th anniversary of Charles Darwin’s birth.

In his On The Origin of Species, published in 1859, Darwin outlined how life evolved through natural selection over millions of years and these British Post Office commemorative stamps – issued on 10 Februrary 1982 in the centenary year of Darwin’s death – each celebrate a different area of Darwin’s study.
15 1/2 pence: The giant tortoises of the Galapagos islands;
19 1/2 pence: The Dark Marine Iguana and the Land Iguana of the Galapagos islands;
26 pence: The Cactus Ground Finch and Large Ground Finch from the Galapagos islands now known as Darwin’s Finches;
29 pence: Prehistoric skulls.
The stamps were designed by David Gentleman and printed in photogravure by Harrison and Sons. The Stanley Gibbons stamp references are 1175 to 1178 inclusive.