This isn't a original idea. I see a similar composition in wired and make my own version. I add colour to picture and also make a little chage in darwin's face for load a soft smile. Next I add the elements: the background (I compound a forest image with a 3d render of a ship model in sea surface, for the beagle), The iguana, the little Woodpecker Finch, the orchids, the pin, the book and, finally, the Orangutan (I'm very proud of the selection Work I make with his fur)
Unfortunatelly, for the cover last image (I make this image for MUY UNTERESANTE spanish magazine) I need to change the orangutan for the little monkey, due to cover image size limits. It was a bad new, because all works OK if you have a orangutan (If you read the Terry Pratchet books, you know why I say this)

Happy Darwin year for all science lovers!