Abstract
The value of the Tree of Life to human well-being and survival is enormous—our species simply cannot thrive without a biodiverse planet; that is, a healthy Tree of Life. The vast importance of the Tree of Life falls into several general categories. First, the immense overall importance of biodiversity not only involves providing food, medicines, and ecosystem services such as clean air and water, but also a second major theme of this chapter is the importance to human well-being of knowledge of how species are related. Knowledge of how organisms are related has predictive value. We all know from our own family trees that relationships matter. For example, if a close relative has a disease or cancer that is genetically inherited, we realize that there is a chance we may have inherited that trait. Similarly, broad knowledge of relationships is fundamental, providing crucial new information regarding the discovery of medicines, combatting disease, crop improvement, while also providing insight into the study of ecosystem function and services (clean air and water). Knowledge of species relationships and the Tree of Life can help in the discovery of new medicines—closely related organisms produce similar chemicals; similarly, that knowledge of relationships is essential to improve crops by identifying close wild relatives that may have important traits (disease resistance, drought tolerance). Knowledge of the Tree of Life can also aid in the study of ecology and conservation efforts. As closely related species will often respond in similar ways to environmental factors such as temperature and moisture availability, the Tree of Life can also provide critical information in predicting how species may respond to climate change.