A team of Yale evolutionary ornithologists has drawn the first complete family tree for all known modern bird species, demonstrating an important and controversial new idea about biodiversity. Joe Hanson explains:
It was thought that any given species would expand and diversify quickly into subspecies (like the many different kinds of honeybees), soon maxing out its environment and filling all the ecological “niches”. Then, competition over limited resources would thin that down to the few most adaptable species. This tree says the opposite, that birds are continuing to diversify even today, and fast.
The center of this tree, anchoring branches built using fossil and DNA sequence data, reaches back nearly 50 million years, to the earliest days of birds branching off of dinosaurs.
Also see this visual history of diagraming evolution.
from Explore http://exp.lore.com/post/34828631225/a-team-of-yale-evolutionary-ornithologists-has