CHICAGO–The earth experienced its biggest mass extinction about 250 million years ago, an event that wiped out an estimated 95% of marine species and 70% of land species. New research shows that this ...

Scientists say the health of a terrestrial ecosystem can be largely determined by three variables: vegetations' ability to uptake carbon, its efficiency in using carbon and its efficiency in using ...

image: In the Cretaceous about 80 million years ago -- well after the end-Permian mass extinction -- the ocean floor was dominated by complex ecosystems that had largely displaced the simple ...