In July 1837, Charles Darwin penned "I think" above his first evolutionary tree. Later, he crucially popularized the notion of an evolutionary tree in his seminal book, The Origin of Species. Today, biologists estimate that there may be as many as 100 million species living on Earth. Morphological, biochemical and genetic evidence suggests that all life on Earth is related and the genealogical relationships between species can be represented by a vast evolutionary tree. In this phylogenetic tree, based on the three-domain system of biological classification introduced by Carl Woese in 1977, cellular life is divided into into the archaea, bacteria and eukaryote domains. Each node of the tree with descendants represents the inferred most recent common ancestor of the descendants, leading right up to a single common origin.
Share your favorite art on soft textured natural white stationery cards, archival-rated with beautiful color reproduction. Each folded card includes a natural white envelope perfect for mailing. Card dimensions are approximately 5.5" x 7.5".