Photosynthesis More recent studies, reported in March 2018, also suggest that photosynthesis may have begun about 3.4 billion years ago. The main source of oxygen in the Earth's atmosphere derives from oxygenic photosynthesis, and its first appearance is sometimes referred to as the oxygen catastrophe. Geological evidence suggests that oxygenic photosynthesis, such as that in cyanobacteria, became important during the Paleoproterozoic era around 2 billion years ago. Modern photosynthesis in plants and most photosynthetic prokaryotes is oxygenic. Oxygenic photosynthesis uses water as an electron donor, which is oxidized to molecular oxygen () in the photosynthetic reaction center. Several groups of animals
What You Need from Me of the album. "What You Need from Me" was later released as the second track on the CD single of "This Is Gonna Hurt" on 16 August 2013. "What You Need From Me" received mixed reviews from music critics. Norbert Schiegel of "G+J Entertainment Media" described the song as "sensational," and Dirk Neuhaus of "Country Rock Magazine" called it a "fantastic track," while Adam Carroll from "Seen It Heard It" thought that the song was one of the weakest tracks from "Rocks and Honey", describing Tyler's voice as "rough and beaten" and that her and Vince Gill's voices do not