Symbiosis: A surprising tale of species cooperation - David Gonzales

source: TED-Ed      2012年3月13日
View full lesson: http://ed.ted.com/lessons/symbiosis-a...
Different species often depend on one another. David Gonzales describes the remarkable relationship of the Clark's nutcracker and the whitebark pine, to illustrate the interdependency known as symbiosis.
Lesson by David Gonzales, animation by Sunni Brown.