Dr. Robert Blankenship - Evolution of Photosynthesis on Earth

[garyruvkun]

This is a magnificent review of a very complex and exciting literature on the diversity of photosynthetic pathways across biology. Dr. Blankenship is clearly a leading light (sorry I could not resist) in this field and presents discoveries the span comparative genomics to the genetics of photosynthesis in microbes, to crystal structures of photosynthetic antenna and reaction centers, with nice astrobiology intersections as well. And world class mechanistic biochemistry from the crystal structural work as well. The best astrobiology talk I have ever seen because every attractive exoplanet for astrobiology rumination (as Carl Sagan would say, billions and billions of them) is illuminated by a parent star glowing somewhere between IR and UV. So photosynthesis is likely to be selected. My own bias is that the photosynthesis on exoplanets will use the same pigments and electron transfer pathways through proteins to the pumping of protons that we recognize on Earth. Not by convergent evolution but by the spread of the same Tree of Life between planetary systems, including Earth. This is not the astrobiology orthodoxy but I enjoy tweaking fields with excessive orthodoxy. We should look for chlorophyll and carotenoid pigment absorption or excitation lines on exoplanets----it takes a lot of chlorophyll to transform photons into biomass so it is abundant and has long lifetime excited states. Thank you Dr. Blankenship.

[kelvinacebron]

Its interesting to know that there is certain degree of independence of the evolution of photosynthesis to that of plants alone. Realizing this may be useful in the prospect of increasing photosynthetic efficiency to meet future demands of human population from crop plants (like food and bioenergy).

[DennisMathias]

Bob, Mr. Tubbs would be proud of you.