History of life on earth. 4.6 bya—when it all began (Precambrian) Earth’s atmosphere changed over time First organisms were likely prokaryotes (3.4 by old fossils) Photosynthetic organisms probably evolved next. How did life first arise?.
Overall increase in species richness over time with five massive extinction events
Today we are in the midst of a six massive extinction event
Massive extinctions may pave the way for new species