Never make assumptions
They assume it was comets and meteorites that brought DNA and RNA to Earth, but it could just have easily been the B-Ark.
Molecules essential to life on Earth may have been delivered to our home world by meteorites and comets, according to the results of experiments. Specifically, a team of brainiacs at the University of Hawaii in the US, National Dong Hwa University in Taiwan, and the Université Côte d’Azur in France, looked into the origin of …
I don't think it was explicitly stated, but the article implied that the specific chemical phosphine is not formed by natural processes on Earth. I am not a chemist, but I guess it's not likely for the crust phosphorus to react with 3 Hydrogen atoms due to it being already bonded with other elements.
On the other hand I also have no idea why phosphine is specifically required to get to the amino acidy bits, my GCSE biology has not stuck with me but I thought you can usually get to chemicals through various routes. In conclusion I both disagree and agree with your skepticism.
phopshine sounds like the name of a photoshop plug-in that makes your pictures shine.
We understand that the earth's atmosphere used to be reducing in the olden days, before photosyntheseis liberated lots of molecular oxygen (O2) that would readily react with any phosphine (PH3) our there to produce phosphates (H3PO4).
I'm normally critical of the panspermia crowd. But it appears that naturally occurring phosphates aren't in a form suitable for life. Plants and microbes convert it into the form we need. But that leaves the small problem of how phosphate got into the form necessary for life before there was any life. If most of the earth's oceans came from comets and that was contaminated with biology-friendly phosphates, then we're quids in. So this research has merit.
I find these 'possibility' type theories both annoying and misleading and agree with Dr. Syntax that the main motivation for them is to get something published.
Everything in the Solar System was made from the same small portion of a much larger molecular cloud nova remnant and this would have been fairly homogeneous until the Sun and planets were well on their way to formation, for without the Sun and planetisimals there would have been nothing to cause differentiation, to separate the different materials in the cloud.
Water is a good example of this: many people now believe that Earth originally had no water at all and that it was all delivered by comets. The reality is that whilst Earth's oceans account for 96.5% of all the surface/near surface water, there's evidence that somewhere between 1.5-11 times this amount exists in the Earth's mantle, hundreds of miles deep, and which wouldn't have got there via comets.
Also doesn't a post formation origin for all sorts of stuff fail the volume test? Presumably there has to be gazillions of comets/roid's hitting proto-earth to deliver enough phosphorus material for life to spontaneously develop.
Isn't deposition prior and during proto-earth formation far more likely? Especially since you have all the time the Earth took to both develop an atmosphere and/or a magnetic field for high power cosmic rays to hit the embedded phosphorus.
> I find these 'possibility' type theories both annoying and misleading and agree with Dr. Syntax that the main motivation for them is to get something published.
I concur and I wonder if what is proposed even qualifies as a theory.
Surely, "hypothesis" would be more appropriate...if we're going to be precise and all.
No wonder creationists still use the tiresome phrase "just a theory" if the rest of us are so careless with our language.
"There's plenty of phosphorus in the Earth's crust so no need to look for extra-terrestrial origins. Oh, silly me. There is. Publications."
My reading of the article is that it is known that elemental phosphorus is created in massive stars, so any phosphorus present on earth must have an extra-terrestrial origin, presumably by way of earth being made from material scattered by the explosion of one or more suitably massive stars.
According to the paper, the phosphates in the earth's crust aren't very water soluble or useful for biology. Plants and microbes overcome this for us but that's no good before there were plants and microbes -- and for life to get going we did need to be swimming in it; every DNA or RNA nucleotide ("letter") needs at least one phosphate anion.
But if comets and meteors are polluted with space-synthesized phosphates of the sort life needs, then perhaps that's where it came from.
Phosphates aren't very water soluble, but that isn't really a problem for basic biochemistry, given that all energetic processes where phosphor is involved ( which are quite important ones ) do not use phosphate, but phosphoric acid.
Which is quite readily soluble in water, and readily formed near, say, the highly acidic environment near an underwater volcano. Which, surprise!, even to this day supports life based on purely anaerobic chemotrophic mechanisms.
People do tend to forget that Early Earth, when life started, was a bit....different... in ecology than nowadays.
Either 'I cant work out how life started on a warm wet chemical rich earth so it must have formed in cold barren space' or 'it was somehow created on another warm wet chemical rich planet and was somehow blasted into space in a way that somehow preserved the life from the massive acceleration required to do so to travel across space unaffected by radiation or time and magically land on earth without burning up in the atmosphere or suffering massive deceleration that regularly causes shocks that can shatter quarts let alone the remaining life in the missile!
Yep. Also, both ribose and deoxyribose are carbohydrates and contain no phosphorous; it's the phosphorous groups which link the sugars to form the backbone of the respective RNA and DNA molecules. DNA is double stranded and RNA is single stranded, no helix shape.
> Don't tell Trump He's got to kick himself out....
Oh, please do actually. Maybe he can practice just the kicking himself part first before getting to the "out" part.
If he needs to he can practice on Kavanaugh, McConnell and Graham first. I'd like that.
From the article:
>They then bombarded them with electrons in a vacuum chamber cooled to 5 Kelvin (-268 degrees Celsius). The electrons mimic the ionizing radiation from cosmic rays and the temperature matches the coldness of space.
Why not also ionizing radiation in the form of gamma, UV and X-rays? I am not sure how many free electrons there are in outer space but there is plenty of EM radiation and not only from the sun.
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