Phylogenetic Tree of Life -The OpenLearn site used to offer this phylogenetic chart in the shape of a tree as a free poster, but no more. They do have an online version of this same illustration, expandable and with links and an explanatory guide.
The swallow chooses a mate for life, it will only nest with that bird and no other. A swallow tattoo is also a symbol for everlasting love and loyalty to the family. Swallows travel long distances, only to find their way back to each other at home.