Lightning May Have Created an Ingredient Needed For Life To Evolve (npr.org) 45
An anonymous reader quotes a report from NPR: In 2016, a family in Illinois thought that a meteorite had hit their backyard. They called up the geology department at nearby Wheaton College to say that whatever struck their property had started a small fire and had left a weird rock embedded in the scorched dirt. "Meteorites, contrary to popular belief, are cold when they hit the ground," says Benjamin Hess, who was an undergraduate at the college but is now a graduate student at Yale University. "My professor readily figured out that that was probably a lightning strike."
When lightning strikes sand, soil or stone, it immediately melts the materials into a glassy clump known as a fulgurite, or lightning rock. When geologists excavated the fulgurite in Illinois, they found something unexpected inside -- an important ingredient for life that had long been thought to be delivered to early Earth by meteorites. A report on the find, in the journal Nature Communications, suggests that this could have been a way for lightning to have played a key role in the emergence of life.
When the researchers dug out the fulgurite in Illinois, they first saw glassy bits on its surface. Below that was a thick, tree-root-like structure extending down about a foot and a half. Hess and two colleagues at the University of Leeds analyzed the minerals inside and found one called schreibersite. This reactive mineral contains phosphorus, an essential element for life. Phosphorus "really plays a key role in a lot of the basic cell structures," says Hess. For example, it makes up the backbone of DNA. Phosphorus was abundant in early Earth, but geologists know that it was mostly inaccessible because it was trapped inside nonreactive minerals that don't dissolve easily in water. One explanation for where the phosphorus came from is meteorites, which can contain reactive minerals like schreibersite. But, according to the researchers, lightning offers an alternative source as it doesn't destroy an entire 100-kilometer area when it strikes and there could have been 1 billion to 5 billion lightning flashes every year when life firm emerged, about 3.5 billion years ago.
When lightning strikes sand, soil or stone, it immediately melts the materials into a glassy clump known as a fulgurite, or lightning rock. When geologists excavated the fulgurite in Illinois, they found something unexpected inside -- an important ingredient for life that had long been thought to be delivered to early Earth by meteorites. A report on the find, in the journal Nature Communications, suggests that this could have been a way for lightning to have played a key role in the emergence of life.
When the researchers dug out the fulgurite in Illinois, they first saw glassy bits on its surface. Below that was a thick, tree-root-like structure extending down about a foot and a half. Hess and two colleagues at the University of Leeds analyzed the minerals inside and found one called schreibersite. This reactive mineral contains phosphorus, an essential element for life. Phosphorus "really plays a key role in a lot of the basic cell structures," says Hess. For example, it makes up the backbone of DNA. Phosphorus was abundant in early Earth, but geologists know that it was mostly inaccessible because it was trapped inside nonreactive minerals that don't dissolve easily in water. One explanation for where the phosphorus came from is meteorites, which can contain reactive minerals like schreibersite. But, according to the researchers, lightning offers an alternative source as it doesn't destroy an entire 100-kilometer area when it strikes and there could have been 1 billion to 5 billion lightning flashes every year when life firm emerged, about 3.5 billion years ago.
Little late... (Score:4, Informative)
These guys are a little late to the game [wikipedia.org].
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Re:Little late... (Score:5, Interesting)
Which is an interesting topic. Its quite true that phosphorus tends to bind tightly in the soil. To get at it today, plants rely on mycorrhizae (and to a lesser degree, independent fungi and fungal associations) to get at it, as they have no ability to do so themselves. Fungal hyphae basically mine into rocks (leaving little curvy tunnels behind) to get at minerals - an energy-intensive process, but for mycorrhizae, they get the energy from their plant hosts, in exchange for the nutrients. This puts bound phosphorus back into play in the soil ecosystem. Lightning is an interesting potential solution for adding both nitrogen and phosphorus into early ecosystems (although I've seen other theories about phosphorus that don't rely on it).
The same can't be said for on the early Earth. No mycorrhizae. Access to nitrogen is also a problem without nitrogen-binding bacteria.
Personally, though, I'm a strong believer in the "scaffolding" view of abiogenesis, in that we've probably gone other forms of life whose mechanism looked nothing like the mechanisms of life today. Vastly simpler, much more inefficient, and poorly selective in their reactions (no DNA, no RNA, no ribosomes, no proteins, just simple organic and/or inorganic compounds in a self-catalytic cycle) - but enough to maintain a functioning hypercycle that maintained sufficient quantities of their reactants. Once you have a hypercycle, the incorporation of any chemistry that makes your reactions more efficient and more selective gives you an evolutionary leg up. So on the back of whatever primitive system existed, our more modern layer of complex organic chemistry could steadily develop, using the previous generation as a scaffold. And once a more efficient system is established, the previous inefficient scaffolding no longer serves a purpose and is lost.
In such a scenario, were meaningful quantities of nitrogen and phosphorus even needed? Noone can really say without knowing what the (lost) scaffolding(s) would have looked like.
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Ne
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I would argue that it's about lightning's ability to do these things, not simply these things, whether that's amino acids or phosphorous.
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"These guys are a little late to the game "
Indeed, even Mary Shelley knew that when she wrote Frankenstein.
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Re:WTF? (Score:5, Informative)
Actually truth. Most of them are cold. If they survive entry at all, they are of course very hot in the upper atmosphere, but by the time they reach the lower atmosphere they have long since slowed down to what the normal terminal velocity would be for a rock that size. That is far too slow to cause heating by friction, so they bleed off their heat in a mile or so of air. Imagine dropping a red-hot rock from an airplane. Do you think it'll still be hot when it reaches the ground? Heavens no. The five miles or so of frigid atmosphere rushing over it as it falls would cool it down.
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...Someone other than me needs to model this shit.
Like, say, NASA?
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What do you mean? African or European swallow?
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I love how everyone here is an expert in bullshit.
Re:WTF? (Score:5, Insightful)
Here's one explanation:
https://wtamu.edu/~cbaird/sq/2... [wtamu.edu]
The meteorites are obviously very cold in space. During their brief fall of only a minute or two through the atmosphere, only the outer skin has time to heat and vaporize. The brief fall through the atmosphere isn't enough to heat the rock's interior, which remains extremely cold. That interior cold quickly cools off the exterior, and in some cases, people have reported seeing frost on them form after landing, even in the middle of a hot summer day.
So, what the hell, huh? I wouldn't have figured on that either.
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Unless it that rock was in sunlight, and small enough for the heating of its exposed side to spread through and keep the rock mostly warm. While the "temperature" of the universe is a very modest 3 degrees K, the temperature of objects near stars is noticeably warmer. The typical temperature of most asteroids, in the asteroid belt is roughly -100 degrees Fahrenheit, but asteroids that strike the Earth are not "typical". the admittedly rare larger meteors that strike the Earth don't slow much in the atmosphe
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Do you also think that a comet's tail is what propels it through its orbit around the sun?
Only when it wags it
schreibersite != RNA (Score:2)
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This is about getting phosphorous free from non-reactive minerals. You can't even have any pathway if there's not enough available phosphorous to begin with.
Science takes little steps most of the time. Get used to it.
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The chain of molecules in which you are particularly focused is itself a chemical machine, after all.
Re:schreibersite != RNA (Score:5, Insightful)
Schreibersite does not have phosphates, phosphites, or any oxyanion. That mineral is a phosphide of iron and nickel, just those three elements. It is a stable mineral under "ordinary" conditions, but the right environment can make it react. Volcanism, acidic environments, and now evidently a high voltage zap can allow it to react to other minerals and salts. The formation of ionic phosphates, phosphites, hypophosphites, and pyrophosphites is the crucial thing that can put phosphorus into the realm of aqueous chemistry, and from there eventually into organic chemistry then life.
To make RNA, you need pyrophosphate, plus nucleotides, plus ribose. It was a long complex evolutionary process to generate enough chemical primitives in the ponds to get to the RNA stage. Key is that these biological and protobiological chemical processes need energy. For this biochemistry to work, "energy" does not mean heating over a Bunsen burner or in a volcanic vent. It means capturing and transporting or transferring a packet of energy from one specific molecule to another, an electron transport chain. There has to be some chemical bond energetic enough to serve as the source battery for these transfers. It turns out phosphorus bonds are that source in biological reactions, which is why they are so central to the development of free running metabolic and replicative chemistry. (The phosphate bonds are a separate issue from the fuel and energy capture chemistry that cells use to get the first pump of "juice" from environmental "food", but once fuel has been burned, phosphorus bonds hold that energy, ready to power other chemical reactions in a cell.) So, understanding how we got from insoluble phosphide minerals to water soluble phosphate salts that could then further evolve into biochemistry, that is a fascinating question.
The authors of TFA estimate how much oxidized phosphorus could have been pumped into water or soil by lightening in the early Earth - not much in a given year, but plenty over millions of years. But, more interesting would be to understand how readily and by what mechanism the phosphide reacts. For instance, in the lightening zap, did the mineral disaggregate by electron transfer from the voltage or electric field, a direct electronic conversion to new molecules, or did simple joule heating allow the elements to "melt" allowing for random association with other atoms in the surrounding area. If joule heating was more relevant, then volcanic activity would seem to be a more massive source of phosphide conversion. On the other hand, lightening could have concentrated phosphates in aqueous and surface locations where a richer mix of protobiological chemistry might have existed. Food for thought.
Old news (Score:2)
Mary Shelley knew this back in 1818.
Empty Space Doesn't Have Lightning (Score:1)
Try again Nimrods.
This is a well known theory (Score:2)
I forgot the name of the TV show, but I remember seeing this on discovery channel over 20 years ago about how life started on earth. It is unknown but many have theorized that it was lightning.
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Funnily enough, the first post was by someone who did remember the name. And others responded that the experiment you mention was about the formation of amino acids, not making phosphorus available to organic chemistry.
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I forgot the name of the TV show, but I remember seeing this on discovery channel over 20 years ago about how life started on earth. It is unknown but many have theorized that it was lightning.
I too remember when the Discovery channel wasn't garbage reality shows. Wow, that was a long, long time ago.
A documentary from the early 1980's (Score:1)
I saw a documentary about early Earth in the 1980's on one of those science programs on television, and it described how lightning delivered the necessary effect (without explaining the effect) to trigger the origin of life.
I preferred the Doctor Who episode "The City of Death" where the explosion of an alien spacecraft caused the formation of early amino acids into primitive, primordial cells. Of course the flaw (not withstanding time travel) was they arrive before life emerged, but the were walking around
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I saw a documentary about early Earth in the 1980's on one of those science programs on television, and it described how lightning delivered the necessary effect (without explaining the effect) to trigger the origin of life.
Didn't Cosmos have an episode where he talked about experiments they were doing like that? I don't remember if electricity was part of it or not, but probably.
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Maybe it was Cosmos, with Carl Sagan and "Billions and Billions..."
It might also have been a retelling of the Miller-Urey experiment. I do remember the talk about lightning, and how it could lead to the rise of simple life. Cosmos and those other science shows were fascinating to me. Of course science class was playing those videos for us to watch...:)
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Two points, in this episode the Doctor arrived before any life existed on Earth. Hence where are the simple plant cells?? The first algae that photosynthesized to reform the planet's atmosphere. And here's a link describing the change in the Earth's atmosphere...the original Earth was not a habitable place...
https://vortex.plymouth.edu/de... [plymouth.edu]
Of course, in science fiction, even British sci-fi of Doctor Who these little details are overlooked. :)
But I liked the explanation for the "explosion of life" on Earth,
Poorly written article (Score:2)
Additionally, electrical discharges were used to simulate lightning in experiments to reproduce primordial conditions, again, a very long time ago.
Also, lightning does NOT create phosphorus.
Phosphorus is an element, the only thing lightning can do is potentially break down phosphorous bearing compounds so that the phosphorus is more easily available for subsequent reactions.
they claim to know the origin of life (Score:2)
Undersea thermal vents (Score:2)
Lightning strikes do not penetrate water very far, and my personal bias is that the most probable abiogenesis (beginning of life) theory involves undersea thermal vents.
Nick Lane (evolutionary biochemistry professor) did a good job of convincing me in that. Here's a link [nick-lane.net] to his website, and a link [goodreads.com] to a superb book of his.
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That book was an eye opening read for me. One of my personal favorites when it comes to scientific explorations on the origins of life.
Mary Shelley already knew that in the 1700's (Score:1)
Obligatory Short Circuit Reference (Score:2)
Johnny Five is Alive! https://www.youtube.com/watch?... [youtube.com]