The fact of common descent, which shows that all life today has descended from a common ancestral source via a process of descent with modification is arguably one of the greatest discoveries in science. It has considerable explanatory and predictive power, explaining things ranging from the biogeographic distribution of species across space and time to the anatomical quirks of the human body. Sadly, it is also one of the most controverted and misunderstood facts, due largely to organised special creationist opposition to deceive and mislead.
An evolutionary tree of life is best understood intuitively by illustration, which is why the interactive Open Tree of Life is such a brilliant educational concept, showing graphically just how life on earth fits together in one massive interrelated network.
- Big Picture Tree - allows you to appreciate the overall structure of life
- Categorizing Life on Earth - allows you to see how species are classified into higher groups
- Explore Species - this allows you to explore the tree at individual species level
The first two are still works in progress, but are definitely worth exploring. An added bonus is that unless specified, the content is licensed under a Creative Commons licence.