Oxygen is a highly toxic compound, that's essentially exhaust gas for photosynthesis.
Plants changed the world way more than humans ever did. They redefined the basic chemistry of all other life on Earth. Because they slaughtered 97% of all life, by accident. What survived had to use/endure oxygen.
Either way. Cyanobacteria isn't a virus, like Agent Smith implied.
> Because they slaughtered 97% of all life, by accident.
And isn’t this also true of humans? We’re not killing other species (and their “habitats”) on purpose, it’s a side effect of Real Goals (eg, we want fuel to heat our homes so we can survive the winter. Or more cynically, Fuel Source Executives need to sell fuel in order to consume yachts and ski vacations).
Also destroing x% of species isn't same destroying x% of life.
If there are ten species of 2 individuals and 80 individuals of another species, you can kill ~90% species while killing only 20% of all life. If you kill 90% of all life you have to kill 90 individuals.