New possibilities for life at the bottom of Earth’s ocean, and perhaps in oceans on other planets
#EarthOceanBottom; #UnderwaterFissures; #HydrothermalVents; #Biochemistry; #Ecology
In the strange, dark world of the ocean floor, underwater fissures, called hydrothermal vents, host complex communities of life. These vents belch scorching hot fluids into extremely cold seawater, creating the chemical forces necessary for the small organisms that inhabit this extreme environment to live, https://phys.org/news.
In a newly published study, biogeoscientists Jeffrey Dick and Everett Shock have determined that specific hydrothermal seafloor environments provide a unique habitat where certain organisms can thrive. In so doing, they have opened up new possibilities for life in the dark at the bottom of oceans on Earth, as well as throughout the solar system. Their results have been published in the Journal of Geophysical Research: Biogeosciences.
On land, when organisms get energy out of the food they eat, they do so through a process called cellular respiration, where there is an intake of oxygen and the release of carbon dioxide. Biologically speaking, the molecules in our food are unstable in the presence of oxygen, and it is that instability that is harnessed by our cells to grow and reproduce, a process called biosynthesis.
But for organisms living on the seafloor, the conditions for life are dramatically different.
“On land, in the oxygen-rich atmosphere of Earth, it is familiar to many people that making the molecules of life requires energy,” said co-author Shock of Arizona State University’s School of Earth and Space Exploration and the School of Molecular Sciences. “In stunning contrast, around hydrothermal vents on the seafloor, hot fluids mix with extremely cold seawater to produce conditions where making the molecules of life releases energy.”
In deep-sea microbial ecosystems, organisms thrive near vents where hydrothermal fluid mixes with ambient seawater. Previous research led by Shock found that the biosynthesis of basic cellular building blocks, like amino acids and sugars, is particularly favorable in areas where the vents are composed of ultramafic rock (igneous and meta-igneous rocks with very low silica content), because…