Though I have been retired for many years as a photosynthesis researcher, some of J. Craig Venter's statements in his article ¹ did not compute with my understanding of evolution and the photosynthetic process.

Venter asserted that Methanococcus jannaschii gets its energy from "hydrogen electrons." Even in deep-sea vents, I doubt that there are hydrogen electrons floating around loose. I suspect the source is hydrogen sulfide or one or more other highly reduced inorganic molecules.

Venter also states, "These photosynthetic microorganisms evolved about three billion years ago," implying M. jannaschii is a photoautotroph. I doubt much light exists in the deep-sea volcanic vents where it is found. M. jannaschii would best be characterized as a chemoautotroph.

Venter is also incorrect when he says that: (a) photosynthetic microorganisms split water and release oxygen, and (b) they use the resulting "hydrogen ions" to "help capture CO₂." Good evidence exists that...