New Massachusetts studyTechnological Institute showed that the ancient ponds (or large puddles) could provide a suitable environment for breeding the first forms of life on Earth - namely ponds, and not the oceans, as previously thought. According to scientists, shallow reservoirs, a depth of about 10 centimeters, could contain a high concentration of what, according to scientists, was a key ingredient for the emergence of life on Earth: nitrogen.
How did life appear on earth?
In shallow pond nitrogen in the form of nitrous oxideswould have a good chance to accumulate in sufficient quantity to react with other compounds and create the first living organisms. In much deeper oceans, nitrogen would be more difficult to establish a significant presence that catalyzes life.
“Our common message is that ifyou think that the origin of life required fixed nitrogen, as many people think, then life would be extremely difficult to originate in the ocean, ”says lead author Sukrit Ranjan, postdok department of the science of Earth, atmosphere and planetology at the Massachusetts Institute of Technology. "It would be much easier for her to appear in the pond."
Ranjan and his colleagues published the results of their work in the journal journal Geochemistry, Geophysics, Geosystems.
By the way, if you are interested in how the studies of the appearance of life on Earth took place - we recommend our longrid in six parts:
Part One: How to make a cage?
Part Two: split in the ranks of scientists
Part Three: Looking for the First Replicator
Part Four: Proton Energy
Part Five: so how to create a cell?
Part Six: The Great Unification
Break the link
If primitive life really originated inAs a result of a key reaction involving nitrogen, scientists suggest, this could happen in two ways. The first hypothesis includes the deep ocean, where nitrogen in the form of nitrogenous oxides could react with carbon dioxide released from hydrothermal sources to form the first molecular building blocks of life.
The second hypothesis about the origin of life, basedon nitrogen, includes RNA - ribonucleic acid, or a molecule that helps encode our genetic information. In its primitive form, RNA was probably a free-floating molecule. Some scientists believe that RNA could chemically form the first molecular chain of life when in contact with nitrogenous oxides. This process of RNA formation could occur either in the oceans or in small lakes and ponds.
Nitric oxides were probably deposited inwater bodies, including oceans and ponds, as the remnants of nitrogen decay in the Earth’s atmosphere. Atmospheric nitrogen consists of two nitrogen molecules linked by a strong triple bond that only an extremely energetically powerful event, lightning, can destroy.
"Lightning is like an explosion of a very powerful bomb,"says ranjan. "It produces enough energy to break this triple bond in our atmospheric nitrogen gas and produce nitrogenous oxides, which can then get into the water."
Scientists believe that in the early atmosphere couldthere should be enough lightning to produce an abundance of nitric oxides that contribute to the birth of life in the ocean. Ranjan says scientists believed that the supply of nitrogen-containing oxides was relatively stable after the compounds hit the oceans.
However, in a new study, he identifies twosignificant "sinkholes" - that is, effects that could destroy a significant part of nitrogenous oxides, especially in the oceans. He and his colleagues looked through the scientific literature and found that nitrogenous oxides in water can break down when interacting with the ultraviolet light of the sun, as well as with dissolved iron released from primitive oceanic rocks.
Ranjan says that like ultravioletradiation and dissolved iron could destroy a significant portion of the nitrogen oxides in the ocean, sending the compounds back to the atmosphere in the form of gaseous nitrogen.
“We have shown that if you consider thesetwo new funnels that no one thought of before, the concentration of nitric oxides in the ocean will decrease by a factor of 1000 compared to what people previously expected, ”says Ranjan.
If we talk about the ocean, ultraviolet light anddissolved iron would make nitrogen-containing oxides much less accessible for the synthesis of living organisms. However, in shallow bodies of water, life would be the best chance to stay afloat. Partly because ponds have a much smaller volume in which the contents will dissolve. As a result, nitric oxides would accumulate to much higher concentrations in ponds. Any funnels — ultraviolet light and dissolved iron — would have less effect on the total concentration of the compound.
Ranjan says that the smaller the pond, the more likely that nitrogen oxides will interact with other molecules, in particular RNA, to catalyze the first living organisms.
"Such ponds could be 10-100 centimeters deep with a surface area of tens of square meters or more," says Ranjan.
It may seem like a puddle, not a reservoir - butthat is the point: in a deeper medium, nitrogenous oxides would simply be too diluted, which would exclude any involvement in the chemistry of the origin of life. According to estimates by other groups, about 3.9 billion years ago, shortly before the first signs of life appeared on Earth, there may have been about 500 square kilometers of shallow reservoirs and ponds around the world.
“This is very small compared to the number of lakes we have today,” says Ranjan. "However, this is quite enough for the beginning of life."
The debate about whether life has arisen in ponds or in the oceans continues, but Ranjan believes that a new study provides strong evidence for the former.
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