A New History of Life

Introduction to the Great Mass Extinctions (1520x16)

Ημερομηνία προβολής: Ιαν 01, 2013

Earth’s fossil record is punctuated with episodes when large fractions of all species abruptly disappeared. Examine the distinction between background extinction and mass extinction. Then look for factors that lead to these periodic catastrophes, and search beyond Earth for a possible explanation.