Evolution of Diversity. Two of the major
transitions that occurred in the evolution of life on earth, long
before any plants or animals were around, involved the evolution of
cyanobacteria and later the first eukaryotic organisms.
(A) Approximately when did the first cyanobacteria
evolve, and what made them so different from earlier
photoautotrophs? Describe at least TWO ways that cyanobacteria
changed the physical conditions on Earth and eventually paved the
way for the evolution of other organisms.