Tree Biology

In the mid-1970s, scientists began using DNA sequences to reexamine the history of all life. Perhaps the most startling discovery to come out of this new field is horizontal gene transfer (HGT), or the movement of genes across species lines. For instance, we now know that roughly eight percent of the human genome arrived not through traditional inheritance from directly ancestral forms, but sideways by viral infection - a type of HGT. In The Tangled Tree David Quammen chronicles these discoveries through the lives of the researchers who made them.

A leaf can be a...shade spiller, mouth filler, tree topper, rain stopper. Find out about the many roles leaves play in this poetic exploration of leaves throughout the year.

Carbon is everywhere. It is constantly moving between the air, water, rocks, and living things. But did you know that none of these things would exist without the carbon cycle? Or that humans have caused the carbon cycle to be out of balance? Learn more about the carbon cycle in this fascinating book.