from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of, relating to, containing or producing oxygen
from the GNU version of the Collaborative International Dictionary of English
- adj. Pertaining to, containing, or resembling, oxygen; producing oxygen.
from The Century Dictionary and Cyclopedia
- Of or pertaining to oxygen.
Wells is not at odds with modern geochemical thought or the scientific data to assert that primitive Earth volcanoes would have contributed to an oxygenic atmosphere.
Some researchers have found that the uranium conglomerates bearing uraninite have a texture and mineralogical makeup (uraninite, pyrite, molybdenite, and sulfides) one would expect if they were deposited by hydrothermal solutions, indicating that the uranium was deposited deep in the earth, far removed from the atmosphere, similar to what is observed happening in the origin of modern and more recently formed uraninite deposits9 (which obviously occurred in an oxygenic atmosphere).
In fact, BIFs from about 2.0 Ga, when the atmosphere was supposedly becoming more oxygenic, look the same as BIFs from earlier pre-Cambrian BIFs19.
There are two pigment-protein complexes that orchestrate the primary reactions of light in oxygenic photosynthesis: photosystem I (PSI) and photosystem II (PSII).
Well-preserved fossils of stromatolites in the Tumbiana Formation, in the Pilbara region, have been dated as 2.72 billion years old, more than 270 million years older than the previous oldest evidence of oxygenic photosynthesis, UNSW doctoral student David Flannery has told a symposium in Perth.
Symposium, in a paper titled "Does the Neoarchaean Fortescue group record the earliest evidence for oxygenic photosynthesis?"
In the couple of billion years that followed, their oxygenic exhaust fumes slowly did the job.
It's not just whether the early atmosphere was nonoxygenic or oxygenic.
The arrival of oxygenic photosynthesis via transport of materials by external means, such as meteorites, could profoundly change the direction of biological evolution on a planet's surface.
His research is focused on genome sequencing and molecular analyses of heliobacteria, proteobacteria and a cyanobacterium with the ability to shift into anoxygenic (oxygen-free) photosynthesis in the presence of sulfide, a possible evolutionary "missing link" between anoxygenic and oxygenic photosynthetic organisms.
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