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44 votes
Accepted

Why aren't there any competing biologies on Earth?

There are indeed almost certainly other potential alternatives to DNA-based biology and the RNA-based biology that may have predated it, which could be used to form viable organisms. Many of them ...
jakebeal's user avatar
  • 6,987
13 votes

How did the first life form on Earth reproduce without DNA?

So earth is estimated to be around 4.5 billion years old, and life has existed for about 3.4-3.9 billion years of that, around >75% the time. For a little perspective, Homo sapiens have been around ...
rg255's user avatar
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10 votes

Why aren't there any competing biologies on Earth?

Jack Szostak's research group has looked at alternatives for RNA as replicators, see e.g. here, and they found that RNA is a far better replicator than the alternatives. So, it seems that RNA-World ...
Count Iblis's user avatar
8 votes

How did the first life form on Earth reproduce without DNA?

Short answer Before the RNA world, mineral surfaces may have facilitated the prebiotic containment and organization of biomolecules. Minerals are believed to have promoted the transition from a dilute ...
AliceD's user avatar
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8 votes

Why aren't there any competing biologies on Earth?

While the discussion of heterochirality was squelched I think it deserves to be addressed explicitly, because unlike most "competing biologies" that one might imagine complementary chiral ...
uhoh's user avatar
  • 5,588
7 votes
Accepted

New earliest life found, what are the implications?

Not a lot, the sample is not conclusively biotic in origin nor is it necessarily much older than known fossils, 3.7 billion vs 3.5 billion. The sample is a few simple hematite filaments, complex ...
John's user avatar
  • 14.7k
7 votes
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How hard would it be to create a protein "by chance"?

In the original column for The Claremont Review of Books, David Gelertner does not suggest starting from atoms, but from amino acids. This changes the calculation slightly: The total count of ...
gilleain's user avatar
  • 880
6 votes

Do we see protocells forming in nature today?

we don't think so, some parts are easy. liposomes form all the time, and can be created in lab quite easily. They quite readily encapsulate any material present when they form, including DNA. So once ...
John's user avatar
  • 14.7k
6 votes

Why aren't there any competing biologies on Earth?

Carbon jakebeal's answer is very good, but the Wikipedia article on DNA alternatives is also very thorough. In particular, when astrobiologists debate whether alien life is likely to be carbon based, ...
Lawnmower Man's user avatar
5 votes

Does Pasteur's experiment contradict an origin of life?

Consider the context. In Antiquity and the Middle Ages from Aristotle on, people thought that many living things (from microbes to mice) would arise through spontaneous generation. Seemed sensible ...
Oosaka's user avatar
  • 3,245
5 votes
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Is abiogenesis possible today?

I will argue that yes, it is POSSIBLE. It is possible on earth like on other planets. Given enough time, matter, and energy, "something" that resembles life will emerge. The problem I see, ...
alec_djinn's user avatar
  • 3,108
5 votes

Is Eugene Koonin's probabilistic argument for the necessity of a multiverse to explain the origin of life sound?

There are two main problems here: The logic assumes that a complete, simplified ribosome is the simplest possible useful unit, so has to spring up by a series of random events. This is extremely ...
lupe's user avatar
  • 203
4 votes
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Experiments on abiogenesis in laboratories

Now the question you have is really very interesting and deep but the short answer is we still don't know enough to be able to decide 1.Precisely when an assembly of molecules and their interactions ...
Yordan Yordanov's user avatar
4 votes
Accepted

Does science have an explanation of how the first "common ancestor" formed in evolution?

Darwin's theory of evolution (and the modern theory of evolution) explains how the current diversity of life developed. Remember, the title of Darwin's book is On The Origin of Species, not the origin ...
Oosaka's user avatar
  • 3,245
4 votes
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A theory about the possible connection between protists and first animalia

Short Answer: Probably the most widely accepted (though certainly not fully accepted) theory of animal evolution is called the Colonial theory. According to the Colonial theory of animal origins, ...
theforestecologist's user avatar
3 votes
Accepted

Can a novel protein domain arise de novo in nature or did all protein domains evolve from a single ancestor?

Yes. Novel protein domains can arise de novo in nature. The evidence is quite solid as those new domains show all the expected mutation patterns and statistical properties (expected for something ...
tsttst's user avatar
  • 1,597
3 votes

Does the lack of "mirror life" tell us anything about abiogenesis?

There is no reason to expect to find opposing chiral life today even if it did exist during the early stages of life's evolution. Everything not incorporated into more recent organisms has been lost, ...
John's user avatar
  • 14.7k
3 votes

Does the lack of "mirror life" tell us anything about abiogenesis?

As far as I know, there isn't too much we know about why life is "left-handed". So far the prevailing hypothesis is that in space there may be a tendency for amino-acids to favor one chiral-state over ...
Matt's user avatar
  • 106
3 votes
Accepted

Does Pasteur's experiment contradict an origin of life?

Pasteur’s experiments demonstrated that the appearance of living matter in spoiled food (soured wine and the like) was not due to so-called spontaneous generation of living organisms, but due to the ...
David's user avatar
  • 25.9k
3 votes

How did the first life form on Earth reproduce without DNA?

You can do without DNA, you need RNA to make proteins. Living organisms create and maintain a bubble that is very far removed from thermal equilibrium. So, you can speculate that at the origin of life,...
Count Iblis's user avatar
3 votes

What is the difference between abiogenesis and spontaneous generation?

What truly differentiates abiogenesis from spontaneous generation? There are three differences. Frequency Abiogenesis occurs very infrequently. Perhaps only once in all of earth's 4.5 billion year ...
JayCkat's user avatar
  • 2,922
3 votes
Accepted

How did Extracellular electron Transport evolve?

Very interesting how journalists can make something catchy out of scientific evidence. Kudos to that! supposedly "eat" electricity Bacteria don't eat electricity. Electricity in it's most basic ...
FoldedChromatin's user avatar
2 votes

Is abiogenesis possible today?

Unlikely Th early earth lacked oxygen which is very harsh on organic chemistry and lacked living things gobbling up all the organic molecules. precursor molecules form all the time on earth but living ...
John's user avatar
  • 14.7k
2 votes

Were Telomeres the Master Key to Abiogenesis

No, they weren't. Interesting hypothesis though! However, that hypothesis is missing a very important piece of information: prokaryotes don't typically have telomeres. Because their DNA is typically ...
Bryan Krause's user avatar
  • 45.9k
2 votes

In the context of heterotrophic theory of abiogenesis, what is an organism that eats other organisms called?

@Artem, it's been a while! Good to see you back on Biology.SE. I doubt that any rigorous terminology exist to describe these "type-0 heterotrophs" living on "non-organismic" organic compounds. You ...
Remi.b's user avatar
  • 68.1k
2 votes

Does Pasteur's experiment contradict an origin of life?

Pasteur proved that modern lifeforms can't form from non-living things. That doesn't prove that there is some hard and bright line that prevents a micell containing enzymatic RNA from changing a bit ...
swbarnes2's user avatar
  • 5,230
1 vote

Do we see protocells forming in nature today?

There are some examples of lab-made protocells although they cannot reproduce and they die because of dilution of their components after a while. In nature we haven't seen any, most probably because ...
alec_djinn's user avatar
  • 3,108
1 vote

Do we see protocells forming in nature today?

In present environment the conditions are not favourable for the new type molecules /coacervates or microspheres formation because the present atmosphere is oxidizing in nature, presence of oxygen ...
Abdul Khan 's user avatar
1 vote
Accepted

Synthetic life creation - status of attempts

There have been lot's of attempts, no success so far, a few groups are still working on. However, many steps forward have been done in the last decades. Starting from the Miller experiment which ...
alec_djinn's user avatar
  • 3,108

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