Climate change and the evolution of C 4 photosynthesis
Oxygen levels in rocks suddenly rise starting 2.5 billion years ago — a spike called the "Great Oxidation Event." The jump was long held up as evidence for when cyanobacteria evolved photosynthesis. But a study published today (March 23) in the journal Nature Geoscience joins a growing body of data that suggests the earliest sun-lovers appeared long before this oxygen spike. 
How CAM plants handle the O2 evolved in photosynthesis during ..
Indeed, it looks like photosynthesis evolved very early in the history of life; the earliest fossils (stromatolites and filamentous microfossils dating to ~3.5 by) look very similar to photosynthetic bacteria that are alive today.
To that end, they have turned their attention to existing organisms. By studying the molecular details of the reactions that green plants, algae and some bacteria use to photosynthesize, and by analyzing the evolutionary relationships among them, scientists are trying to piece together a cogent historical narrative for the process.
Shining light on the evolution of photosynthesis - …
Taken together, “heliobacteria have a simplicity in their organization that’s surprising compared to the very sophisticated systems you have in plants and other organisms,” said , a leading figure in photosynthesis research at Washington University in St. Louis. “It harkens back to an earlier evolutionary time.”
Shining light on the evolution of photosynthesis
Cardona, who was not involved in the recent study but has begun interpreting its results, thinks he may have found a hint in the heliobacterium reaction center. According to him, the complex seems to have structural elements that would have later lent themselves to the production of oxygen during photosynthesis, even if that wasn’t their initial purpose. He found that a particular binding site for calcium in the heliobacteria’s structure was identical to the position of the manganese cluster in photosystem II, which made it possible to oxidize water and produce oxygen.
for the evolution of photosynthesis would have ..
But not only are you (and every other heterotroph) energetically dependant on photosynthetic organisms for food, you are also indebted to them for changing the planet and stimulating the evolution of eukaryotic and multicellular life.
Early Evolution of Photosynthesis | Plant Physiology
Both types of photosystem come together in green plants, algae and cyanobacteria to perform a particularly complex form of photosynthesis—oxygenic photosynthesis—that produces energy (in the form of ATP and carbohydrates) as well as oxygen, a byproduct toxic to many cells. The remaining photosynthetic organisms, all of which are bacteria, use only one type of reaction center or the other.
To show Oxygen is evolved during Photosynthesis - YouTube
The presence of oxygen in the oceans 2.5-2 billion years ago, indicated by the presence of sedimentary deposits with oxidized iron (banded iron formations), indicates the evolution of this more advanced type of photosynthesis that evolved in ancient photosynthetic bacteria.