[dead]

But the photosynthetic mechanism is so complicated that scientists think it evolved only once on our own planet.

That’s some jackassery masquerading as science. I think the author of this article is in over his head and misunderstood something a scientist told him.

[Moonman62]

Nope. Photosynthesis appears to be an evolutionary singularity. Abiogenesis is, too. The appearance of eukaryotes would be another one.