MIT: Brewing Up Earth's Earliest Life 3.9 Billion Years Ago

[bystander]

Brewing Up Earth's Earliest Life
Massachusetts Institute of Technology | 2018 Apr 09

Large concentrations of sulfites and bisulfites in shallow lakes may have set the stage for Earth’s first biological molecules.

Around 4 billion years ago, Earth was an inhospitable place, devoid of oxygen, bursting with volcanic eruptions, and bombarded by asteroids, with no signs of life in even the simplest forms. But somewhere amid this chaotic period, the chemistry of the Earth turned in life’s favor, giving rise, however improbably, to the planet’s very first organisms.

What prompted this critical turning point? How did living organisms rally in such a volatile world? And what were the chemical reactions that brewed up the first amino acids, proteins, and other building blocks of life? These are some of the questions researchers have puzzled over for decades in trying to piece together the origins of life on Earth.

Now planetary scientists from MIT and the Harvard-Smithsonian Center for Astrophysics have identified key ingredients that were present in large concentrations right around the time when the first organisms appeared on Earth.

The researchers found that a class of molecules called sulfidic anions may have been abundant in Earth’s lakes and rivers. They calculate that, around 3.9 billion years ago, erupting volcanoes emitted huge quantities of sulfur dioxide into the atmosphere, which eventually settled and dissolved in water as sulfidic anions — specifically, sulfites and bisulfites. These molecules likely had a chance to accumulate in shallow waters such as lakes and rivers. ...

Sulfidic Anion Concentrations on Early Earth for Surficial Origins-of-Life Chemistry - Sukrit Ranjan et al

• Astrobiology (online 2018 Apr 08) DOI: 10.1089/ast.2017.1770
  arXiv.org > astro-ph > arXiv:1801.07725 > 23 Jan 2018

[neufer]

Brewing Up Earth's Earliest Life
Massachusetts Institute of Technology | 2018 Apr 09

Large concentrations of sulfites and bisulfites in shallow lakes may have set the stage for Earth’s first biological molecules.

Now planetary scientists from MIT and the Harvard-Smithsonian Center for Astrophysics have identified key ingredients that were present in large concentrations right around the time when the first organisms appeared on Earth. The researchers found that a class of molecules called sulfidic anions may have been abundant in Earth’s lakes and rivers. They calculate that, around 3.9 billion years ago, erupting volcanoes emitted huge quantities of sulfur dioxide into the atmosphere, which eventually settled and dissolved in water as sulfidic anions — specifically, sulfites and bisulfites. These molecules likely had a chance to accumulate in shallow waters such as lakes and rivers. ...

The Chemical Weapons of Onions and Garlic
By HAROLD McGEE/The New York TimesJUNE 8, 2010

<<WHAT do garlic and onions have in common with gunpowder? A lot. They’re incendiary. They can do harm and they delight. Sulfur is central to their powers. Dr. Block’s book “Garlic and Other Alliums: The Lore and the Science” was published earlier this year by the Royal Society of Chemistry. “It’s still astounding to me what happens when you cut or bite into an onion or a garlic clove,” Dr. Block told me in a telephone conversation last month. “These plants originated in a very tough neighborhood, in Central Asia north of Afghanistan, and they evolved some serious chemical weapons to defend themselves.” Their sulfur-based defense systems give the alliums their distinctive flavors. The plants deploy them when their tissues are breached by biting, crushing or cutting. The chemicals are highly irritating, and discourage most creatures from coming back for seconds. They kill microbes and repel insects, and they damage the red blood cells of dogs and cats. Never feed a pet onions or garlic in any form.>>