Has the Origins of Human Life on Earth Been Discovered?

[Asbo Zaprudder]

Wrong. Earth didn't even have any oxygen during the first two billion years of life. We've only had an oxygenated atmosphere for about two billion years or so. The first life didn't use oxygen. Proof of life in the fossil record goes back 3.5 to 3.8 billion years.

Yeah, the Dunning-Kruger effect is strong with him. I wish he'd get clued up by watching some of the more decent YouTube videos on science - I'm not even expecting any book reading. None of us are 100% correct all of the time but I've rarely seen anyone be so wrong so consistently.

 

[Spider]

Yeah, the Dunning-Kruger effect is strong with him. I wish he'd get clued up by watching some of the more decent YouTube videos on science - I'm not even expecting any book reading. None of us are 100% correct all of the time but I've rarely seen anyone be so wrong so consistently.

After reading some of his posts, I feel I've fallen into an argument with someone akin to a flat earther.

 

[Asbo Zaprudder]

After reading some of his posts, I feel I've fallen into an argument with someone akin to a flat earther.

Thankfully, nowhere nearly so annoying. Flat-earthers are often motivated by religious beliefs in wanting to place themselves at the centre of creation as God's most beloved creatures. It's another form of Solipsism.

 

[Dryson]

https://ucmp.berkeley.edu/bacteria/cyanofr.html#:~:text=The cyanobacteria have an extensive,older: 3.8 billion years old!

Basing knowledge off of what is easily accessible is not science.

Cyanobacteria is able to adapt to the vacuum of space very well. Therefore, the possibility of Life coming to Earth from some other location in the galaxy is still likely.

The fact that cyanobacteria have not been found instead of Tardigrades, which have been proven to be the most resilient life capable of surviving the vacuum of space and extreme cold and hot temperatures, proves to me the article from Berkeley is skewed and hasn't been expanded on for many years.

The data regarding the oldest fossils on Earth is nearly 30 years old.

After atmospheric oxygen levels spiked 2.4 billion years ago, not much happened on Earth for another billion years. Earth was so staid that scientists call this stretch of time the "boring billion." Things were pretty quiet tectonically, too: The continents were stuck in a supercontinental traffic jam for most of the boring billion. Many researchers think there's a link between the lack of tectonic activity and the boring billion — perhaps life needed a kick from drifting continents to drive evolution past photosynthesis, toward complex bodies.

https://www.livescience.com/46593-how-earth-formed-photo-timeline.html

http://www.bbc.com/earth/story/20150313-the-toughest-animals-on-earth#:~:text=are truly ancient.-,Fossils of tardigrades have been dated to the Cambrian period,first complex animals were evolving.

Tardigrades have been found as far back at 500 million years ago. Scientists have even been able to bring a Tardigrade back to life after 8 years, unlike, cynobacteria.

Bacteria and Tardigrades have not been found on Mars which formed at the same time Earth did and from the same inner solar system dust disk.

Therefore, something had to have happened later in the evolution of the Earth to cause plate tectonics on Earth to continue. I think Solar Asteroids or asteroids orbiting the Sun that formed during the same time the Inner Planets formed collided with Earth, which caused the plates of Earth to continue to move.

Since Mars and Earth formed at the same time and from the same circumstellar material, Bacteria should have been found on Mars by now. The same cyanobacteria that the article from Berkeley refutes as being the oldest fossils on Earth.

But since cyanobacteria hasn't been found on Mars, then an event that took place later on in the evolution of Earth brought the first life to Earth from outside of the solar system.


Edited.

Here is something else interesting to think about.

It's a time when the Earth is still partially molten and circumstellar dust is still present. As the Earth orbits the Sun, I can't believe for a moment that the swath the Earth is taking is the only swath of dust that would contain the life building materials that has become, as we all know it, for the most part, DNA and RNA and all of the other fun stuff that goes into life's mix.

What could have happened is, smaller asteroids orbiting the Sun but in the same general swath that the Earth was in, collected life building material and then later collided with the Earth, after plate tectonics settled.

I would also have to say that the Golden Zone in the Goldilocks Zone would have to be a third of the distance from Earth to Mars on either side of Earth.

 

[dupersuper]

Cyanobacteria is able to adapt to the vacuum of space very well. Therefore, the possibility of Life coming to Earth from some other location in the galaxy is still likely.

No, something being possible doesn't automatically make it likely.

 

[Asbo Zaprudder]

Yeah, there's been research done on how cyanobacteria cope with vacuum and radiation but it would take tens of thousands of years for a desiccated bacterium to cross between star systems. It's possible but if it happened, it would imply that all organic life is likely to be very similar within our galaxy. We don't yet have any substantive evidence for panspermia.

Cyanobacteria: The first seed of space colonization | by Jatan Mehta | TeamIndus Foundation | Medium
(PDF) CyanoSpace: cyanobacteria form extreme deserts to space (researchgate.net)

Tardigrades are hardy little buggers but they are multicell eukaryotes in the family Ecdysozoa and much nearer to nematode worms than to bacteria. I guess it's just possible that they could be blasted intact from one star to another and survive but I suspect this is much less likely than for cyanobacteria.

Tardigrades: Size, Lifespan, Diet, and Other Shocking Facts (scienceabc.com)

In any case, as I have mentioned previously, the science tells us that eukaryotes most likely descend from both archaea and bacteria. The bacterium involved was likely not a cyanobacterium although lines of descent are problematic for bacteria as genetic material can be transferred between different species through lateral gene transfer. They can also transfer DNA to eukaryotes although this would have to be done to sex cells or their precursors to get passed on.

Prokaryotes: Bacteria & Archaea | Organismal Biology (gatech.edu)
^ @Dryson - please read this article at least.
Symbiogenesis - Wikipedia
Lateral Gene Transfer Between Humans and Microbes | The Scientist Magazine® (the-scientist.com)

Just as an aside, I thought it amusing to estimate the number of cells in a tardigrade. Taking the dimensions of a typical specimen as 0.5mm x 0.25mm x 0.25mm, the volume is 3 x 10^-11m. Assuming a density similar to water, the mass would be 3 x 10^-8 kg. The mass of a typical eukaryotic cell is roughly 2 x 10^-12 kg so a tardigrade contains perhaps 15,000 cells. The nematode worm C. elegans, has precisely 1031 cells in males and 959 cells in hermaphrodites that can act as females or self-fertilise. A 60kg human contains of the order of 30 trillion cells, of which about 91.4% are to do with the blood - 84% red blood cells, 4.9% platelets and 2.5% bone marrow cells. (IMO it's a bit of a stretch to call a human red blood cell a cell as it doesn't contain a nucleus, it doesn't divide, and it lasts about 120 days before having to be replaced from erythroblasts in the bone marrow.)

» How many cells are there in an organism? (bionumbers.org)

 

[Dryson]

No, something being possible doesn't automatically make it likely.

Cyanobacteria is present all over the Universe and just not on Earth.

If bacteria doesn't exist on other planets then why does NASA trouble itself to search for bacteria?

 

[Asbo Zaprudder]

Evidence please. The only place in the universe that we know for certain has life is the Earth.

Fred Hoyle and Chandra Wickramasinghe claimed 40+ years ago that there was spectroscopic evidence for the presence of cellulose in space but the evidence just wasn't convincing enough for most scientists. They were correct about the presence of other complex organic molecules in interstellar molecular clouds, however.

Indian scientists have claimed to have collected new forms of bacteria in the stratosphere but there's no definitive proof that the microbes are not of terrestrial origin.

 

[dupersuper]

Cyanobacteria is present all over the Universe and just not on Earth.

If bacteria doesn't exist on other planets then why does NASA trouble itself to search for bacteria?

Did you just use the search for something as proof that it exists?

 

[Asbo Zaprudder]

We also search for intelligent life out there but there seems to be precious little of it down here.

 

[CorporalCaptain]

We also search for intelligent life out there but there seems to be precious little of it down here.

We're a work in progress.

 

[BillJ]

Cyanobacteria is present all over the Universe and just not on Earth.

If bacteria doesn't exist on other planets then why does NASA trouble itself to search for bacteria?

You truly have a dizzying intellect...

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[StarCruiser]

Yeah, there's been research done on how cyanobacteria cope with vacuum and radiation but it would take tens of thousands of years for a desiccated bacterium to cross between star systems. It's possible but if it happened, it would imply that all organic life is likely to be very similar within our galaxy. We don't yet have any substantive evidence for panspermia.

Cyanobacteria: The first seed of space colonization | by Jatan Mehta | TeamIndus Foundation | Medium
(PDF) CyanoSpace: cyanobacteria form extreme deserts to space (researchgate.net)

Tardigrades are hardy little buggers but they are multicell eukaryotes in the family Ecdysozoa and much nearer to nematode worms than to bacteria. I guess it's just possible that they could be blasted intact from one star to another and survive but I suspect this is much less likely than for cyanobacteria.

Tardigrades: Size, Lifespan, Diet, and Other Shocking Facts (scienceabc.com)

In any case, as I have mentioned previously, the science tells us that eukaryotes most likely descend from both archaea and bacteria. The bacterium involved was likely not a cyanobacterium although lines of descent are problematic for bacteria as genetic material can be transferred between different species through lateral gene transfer. They can also transfer DNA to eukaryotes although this would have to be done to sex cells or their precursors to get passed on.

Prokaryotes: Bacteria & Archaea | Organismal Biology (gatech.edu)
^ @Dryson - please read this article at least.
Symbiogenesis - Wikipedia
Lateral Gene Transfer Between Humans and Microbes | The Scientist Magazine® (the-scientist.com)

Just as an aside, I thought it amusing to estimate the number of cells in a tardigrade. Taking the dimensions of a typical specimen as 0.5mm x 0.25mm x 0.25mm, the volume is 3 x 10^-11m. Assuming a density similar to water, the mass would be 3 x 10^-8 kg. The mass of a typical eukaryotic cell is roughly 2 x 10^-12 kg so a tardigrade contains perhaps 15,000 cells. The nematode worm C. elegans, has precisely 1031 cells in males and 959 cells in hermaphrodites that can act as females or self-fertilise. A 60kg human contains of the order of 30 trillion cells, of which about 91.4% are to do with the blood - 84% red blood cells, 4.9% platelets and 2.5% bone marrow cells. (IMO it's a bit of a stretch to call a human red blood cell a cell as it doesn't contain a nucleus, it doesn't divide, and it lasts about 120 days before having to be replaced from erythroblasts in the bone marrow.)

» How many cells are there in an organism? (bionumbers.org)

You know - it's really not fair confusing him with legitimate science...

 

[Asbo Zaprudder]

You know - it's really not fair confusing him with legitimate science...

It does seem like someone bought a science textbook and then passed it multiple times through Google Translate before it ended up back in English. I'm thinking along the lines of the game played by the protagonist Joe Fernwright in Galactic Pot-Healer by P K Dick:

Joe finds himself constantly depressed and idle at the opening of the novel. He is unemployed and on a war veteran's social security benefit, given that ceramic pottery has been replaced by plastics, and his profession is not in great demand. He longs for purpose and meaning in life. His one entertainment is to call various friends on the worldwide telephone network and swap puzzles. These puzzles are created by translating a common English proverb or phrase into another language by using a language translation computer, and then translating it back to English the same way. The object of the game is to guess the original from the double translation.

Galactic Pot-Healer - Wikipedia

 

[publiusr]

Luisi Luigi did work on micelles…that cells can occur before genetic material to fill them. Smoker Cavitation to have bubbles that exist to serve as tiny Petri dishes with double helix vortex spun-up material…that is my guess at abiogenesis…bubbles breaking and causing unzippering that set up a pattern? That’s your Providincal hand as it were…to hazard a guess.

Could that small planet you are referring to possibly have been a solar orbital?

I had the arxiv link somewhere.

There is a part of me that wonders if we might have had much more water than we do now…and this last near fatal graze removed just enough to allow for evolution to really take off.

The opposite of a mean parent throwing a child in a lake saying “sink or swim.”

The Great Splashout might have been “crawl or die”

We weren’t ways for the universe to “know itself” or even feel pain.

No…I think the point of life…if it ever had a point—-is for the universe to at last be able to scream.

Nonexistence is far more restful.

There is a man (Ventner?) who wants to do with life what Godel’s predecessors tried with math. He came up with the idea of a “minimal cell.”

That might point the way back to the spin-up.

As to forward..he noted that as colony creatures with DNA from bites and who knows what…we aren’t all human. So he came up with the idea of a “minimal human”. An Adam & Eve yet to be. I have images of them as the hapless Eloi to our Morlocks…in some ways…we are already what Palmer and Norris were in THE THING…trying to undo the assimilation, as it were.

 

[oldtrekkie]

When the giant asteroid hit the Earth most of the energy of the shock was converted into heat that elevated the temperature of the asteroid in question to more than a thousand degrees Celcius. That's more than enough to sterilize anything "alive" in the asteroid itself.

 

[Asbo Zaprudder]

There are so many improbable steps in getting from simple organic compounds to multicellular eukaryotic life or even unicellular prokaryotic life with their unbelievably intricate molecular nanomachinery that I feel obliged to invoke the many worlds hypothesis to explain the numerous fortunate rolls of the dice that appear to have been necessary. The same goes for obtaining the observed fundamental particles and other aspects of the observable universe. Copernicus removed the Earth from the centre of the limited medieval cosmos. Everett removed man from the centre of existence. We'd like to think we're important and special. We're really not.

 

[Dryson]

If there was more water on Earth before the asteroid struck was that water vaporized to become the clouds in the sky?

If all of the clouds were converted into water, how much more liquid water would the Earth have on its surface?
When the asteroid hit the Earth, it basically split the Earth open, slightly, just like the shell around a seed opens slightly when seed begins to sprout.

As a result, water could have been able to seep into the lower layers of Earth to help cool the Earth along with helping to create layers of fluid that aided in plate movement.

 

[oldtrekkie]

There are so many improbable steps in getting from simple organic compounds to multicellular eukaryotic life or even unicellular prokaryotic life with their unbelievably intricate molecular nanomachinery that I feel obliged to invoke the many worlds hypothesis to explain the numerous fortunate rolls of the dice that appear to have been necessary. The same goes for obtaining the observed fundamental particles and other aspects of the observable universe. Copernicus removed the Earth from the centre of the limited medieval cosmos. Everett removed man from the centre of existence. We'd like to think we're important and special. We're really not.

On the other hand, each litre of water contains billions of billions of molecules that interact in billionths of seconds. If there is any kind of selection system the kind we see in the game of life for example. It's conceivable that given enough time any kind of chemical soup under certain circumstances will eventually spontaneously produce living organisms. We just haven't enough resources to prove that mathematically yet but maybe someday we will.

 

[Asbo Zaprudder]

On the other hand, each litre of water contains billions of billions of molecules that interact in billionths of seconds. If there is any kind of selection system the kind we see in the game of life for example. It's conceivable that given enough time any kind of chemical soup under certain circumstances will eventually spontaneously produce living organisms. We just haven't enough resources to prove that mathematically yet but maybe someday we will.

I suspect we might never know the answer about life's origin for certain. One estimate of the probability of life forming by random assembly is 10^40,000 in the life time of our universe - which is incredibly unlikely. However, all such estimates could be wildly wrong if the assumptions are faulty. We don't know if conditions in this universe favour abiogenesis given a narrow or a broad range of different initial conditions. For example, on the Earth, it is thought to be more likely in a confined environment such as lipid vesicles forming within an alkaline vent containing iron sulfide minerals through which hydrogen is percolating into an acidic ocean rich in carbon dioxide. However, that isn't the only possible starting location that has been mooted as I'm sure you are aware.

An infinite number of alternate universes increases the probability to 1 of life occurring somewhere in the multiverse. However, if it is the case that the probability per universe is vanishingly small, life might only have appeared once in this universe on the Earth. Of course, this is all just vacuous speculation and not science. If we find life elsewhere in our cosmos, perhaps we'll get a better handle on the probabilities.