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I think TFA's title is wrong; it doesn't (seem to) dispute the age of the first photosynthesizing cyanobacteria. Apparently they have pushed back the age of the

I think TFA's title is wrong; it doesn't (seem to) dispute the age of the first photosynthesizing cyanobacteria. Apparently they have pushed back the age of the earliest "thylakoid membranes", which (on my reading - I didn't find it clear) are required for a cell to incorporate a cyanobacterium. So perhaps (if I read it correctly) the title should be "Fossil evidence of photosynthetic cells gets a billion years older". But even that is a stronger claim than TFA makes; the presence of thylakoid membranes doesn't mean that the cyanobateria manifesting them were incorporated in photosynthetic cells.

trompetenaccoun 3y ago
The author seems to make the false assumption that the real "hard" evidence for photosynthesis is fossil-based. And so that this is now the best proof that exists. I'm guessing the article is confused because he's not an expert in the field and probably hasn't looked into it deeply. That's frankly the problem with most pop-science reporting. Even if they wanted to, nobody who writes for a living has the time to actually become an expert in so many different fields. So they write about things they don't understand.
andrewflnr 3y ago
The cyanobacterium itself is a photosynthetic cell. Bacteria are cells. The thylakoid membrane is a structure inside those cells. You seem to be confusing this with the origin of eukaryotic, chloroplast-based photosynthesis, which is indeed a different question.
- denton-scratch 3y ago
  You're right: I probably confounded "cells" with eucaryotic cells. My understanding (from school biology half a century ago) is that a strong candidate for the origin of chloroplasts is cyanobacteria, incorporated as guests. I'm not sure that eucaryotic cells are the only kind of "big" cells that could adopt cyanobcteria as organelles. Anyway, I wasn't considering bacteria as "cells".
  - andrewflnr 3y ago
    Yeah, the chloroplasts=cyanobacteria thing is pretty near settled these days. :)

trompetenaccoun 3y ago

The author seems to make the false assumption that the real "hard" evidence for photosynthesis is fossil-based. And so that this is now the best proof that exists. I'm guessing the article is confused because he's not an expert in the field and probably hasn't looked into it deeply. That's frankly the problem with most pop-science reporting. Even if they wanted to, nobody who writes for a living has the time to actually become an expert in so many different fields. So they write about things they don't understand.

andrewflnr 3y ago

The cyanobacterium itself is a photosynthetic cell. Bacteria are cells. The thylakoid membrane is a structure inside those cells. You seem to be confusing this with the origin of eukaryotic, chloroplast-based photosynthesis, which is indeed a different question.

denton-scratch 3y ago
You're right: I probably confounded "cells" with eucaryotic cells. My understanding (from school biology half a century ago) is that a strong candidate for the origin of chloroplasts is cyanobacteria, incorporated as guests. I'm not sure that eucaryotic cells are the only kind of "big" cells that could adopt cyanobcteria as organelles. Anyway, I wasn't considering bacteria as "cells".
- andrewflnr 3y ago
  Yeah, the chloroplasts=cyanobacteria thing is pretty near settled these days. :)