Moving Towards Life

How did chemisty and oceans produce this?

There is still a problem:

So, chlorophyll evolves to more complex forms so that it can capture and store enough UV energy to breaking the hydrogen-oxygen bond in water.

Now we have a mechanism to deliver Oxygen to the atmosphere via the aerobic photosynthesis of blue-green algae. But, the oxygen does not initially go into the earth's atmosphere:

Addition of O2 to the Atmosphere:

Today, the atmosphere is ~21% free oxygen. How did oxygen reach these levels in the atmosphere? Revisit the oxygen cycle: