11 hours ago
Leading theory for how life on Earth began is 'highly unlikely', says contentious new paper
https://www.sciencealert.com/leading-the...-new-paper
EXCERPTS: If you ask a scientist how life appeared on Earth, they will usually begin the story in one of two places: A warm, mineral-rich pool on the surface of our primordial planet. Or a deep-sea vent pumping warm, hydrogen-rich fluid through the ocean floor.
Both tales are highly engaging, but only one holds any water, according to a provocative new take by geochemist Benjamin Tutolo from the University of Calgary. Tutolo's perspective is now laid out in the peer-reviewed journal PNAS.
"Hydrothermal vent hypotheses for the origin of life are ingrained in our culture to the point that many of us no longer question them," Tutolo told ScienceAlert. "I even have a children's book that I used to read to my kids that points to hydrothermal vents as the location where life originated."
Based on the evidence at hand, however, Tutolo thinks it is highly unlikely that life originated in hydrothermal vents.
"That would require the systems to work in ways that we know that they do not, and that is obviously a fundamental issue," he said. [...] Tutolo agrees that the hypothesis has remained consistent through the years. But he argues it is now inconsistent with current evidence.
Today, we know that these deep-sea vents are not as alkaline as we once thought, nor as sulfur-rich. We also know more about what Earth's oceans looked like almost four billion years ago, when life first appeared. [...] What's more, the powerful proton gradients required for the alkaline-vent origin-of-life hypothesis may not have existed here either.
[...] "These problems are so fundamental that hydrothermal vent hypotheses for the origin of life need to be taken back to the drawing board," Tutolo said. "They all rely on a similar series of assumptions, and this work demonstrates that these assumptions are misguided."
So why has this hypothesis persisted despite emerging evidence to the contrary? Tutolo says part of the problem is wishful thinking... (MORE - missing details)
https://www.sciencealert.com/leading-the...-new-paper
EXCERPTS: If you ask a scientist how life appeared on Earth, they will usually begin the story in one of two places: A warm, mineral-rich pool on the surface of our primordial planet. Or a deep-sea vent pumping warm, hydrogen-rich fluid through the ocean floor.
Both tales are highly engaging, but only one holds any water, according to a provocative new take by geochemist Benjamin Tutolo from the University of Calgary. Tutolo's perspective is now laid out in the peer-reviewed journal PNAS.
"Hydrothermal vent hypotheses for the origin of life are ingrained in our culture to the point that many of us no longer question them," Tutolo told ScienceAlert. "I even have a children's book that I used to read to my kids that points to hydrothermal vents as the location where life originated."
Based on the evidence at hand, however, Tutolo thinks it is highly unlikely that life originated in hydrothermal vents.
"That would require the systems to work in ways that we know that they do not, and that is obviously a fundamental issue," he said. [...] Tutolo agrees that the hypothesis has remained consistent through the years. But he argues it is now inconsistent with current evidence.
Today, we know that these deep-sea vents are not as alkaline as we once thought, nor as sulfur-rich. We also know more about what Earth's oceans looked like almost four billion years ago, when life first appeared. [...] What's more, the powerful proton gradients required for the alkaline-vent origin-of-life hypothesis may not have existed here either.
[...] "These problems are so fundamental that hydrothermal vent hypotheses for the origin of life need to be taken back to the drawing board," Tutolo said. "They all rely on a similar series of assumptions, and this work demonstrates that these assumptions are misguided."
So why has this hypothesis persisted despite emerging evidence to the contrary? Tutolo says part of the problem is wishful thinking... (MORE - missing details)
