A splendid video about evolution

@sbu, I'm surprised that you didn't respond to this, because, on a bit of cursory reading and skimming of the papers to which you linked, David is completely wrong here. They solve the problem of how homochirality arose prebiotically, that is, prior to biological cells, which is not the "simpler" problem to which David refers but the "harder" one.

If I'm mistaken about this, then please correct me.

OK - I have been a bit distracted by some real-life things, but now I want to tackle all this by putting it into a slightly larger context.

We are talking about the origin of life, so what would the Earth look like prior to this wondrous event? It is customary to assume that a large quantity of organic chemicals formed on the Earth as a soup. It is also assumed that the components of this soup undergo chemical interactions prompted by heat from the sun, lightning flashes, or whatever. Chemists have some idea what such a soup would be like because many organic chemistry reactions produce a certain amount of 'tar' as well as some desired product(s). The tar is rarely interesting because it consists of chemicals just linked together at random. This is

Problem 1 - how do we end up  with a nice selection of biological monomers waiting to be coupled together?

OK, now suppose that somehow the first problem is resolved, and we have a nice soup of exactly the right chemicals to form life (think DNA bases, amino acids, sugar molecules), except that all the optically active chemicals are present as a 50:50 mixture of L and D forms - a racemic mixture. We still have the problem that any polymerisation will happen in an undirected way.

Remember that in life as we know it, enzymes, which are optically active, catalyse the creation of every biopolymer, but we can't create a coherent story for the creation of life if we assume we have components  that we don't yet have.

Polymerisation by heat or using crystal surfaces might be possible, but this will be utterly haphazard. All the monomers have multiple ways they can couple together, so the chance of ending up with a linear chain of (say) 100 units is incredibly small.Obviously, one of the problems at this stage is to use the

The fact that each of the monomers (with the exception of the amino acid glycine) comes in L and D versions is a severe problem because if a growing chain gets extended by the wrong optical isomer, the chain will become kinked and therefore biologically useless. There is no plausible way to make the primordial soup mainly of one set of optical isomers. This problem remains until polymerisation is controlled by enzymes which are themselves optically active.

Imposing a slight bias on the number of these isomers doesn't really solve the problem at all. Thus we have:

Problem 2 How do we get Biological polymers when there are so many ways these processes can be led astray?

Even after this step we have the biggest problem of all. You can synthesise as much DNA as you like, but unless it has useful codes, it will not do anything. Those codes need a master biochemist to work out a sequence of amino acid residues that would result in a useful protein and encode that in some DNA.

Problem 3 How do we get a useful code into the DNA?

There are still other problems, but let me point out one. Suppose by some gigantic fluke a single-celled organism were to appear in the soup. How is it supposed to survive? What will it eat, and won't it succumb to the many poisons that will be floating in the brew - cyanide for example.

I think life cannot be created without designer(s) of some sort, and that any such organism could not possibly evolve by RM+NS because as discussed previously DNA cannot evolve.

Even though I am not a Chistian, I must acknowledge that the work done by people in the DI has completely smashed the old, very vague concept of how life appeared and diversified on Earth.

David

What AWARE intended to measure was awareness during resuscitation, and whether cardiac arrest patients were up on the ceiling. They were not measuring the visual accuracy of recalled NDE OBEs, a missed opportunity, then they made the same mistake again with the design of AWARE II.

I think the fundamental problem was that there was supposedly a risk that people being resuscitated - but still with no heartbeat - could HEAR what was going on at the time!

This is one of my beefs with orthodox science, it goes to such extreme lengths to destroy evidence that is paranormal (for want of a better word) that it destroys potentially genuine phenomena without really caring.

If you are totally convinced that X is impossible, you can't act as an unbiased scientist on the issue.

It is obviously almost impossible to interfere with the operation of the resuscitation process, by for example arranging for someone to join the team in a suitably sterilised monkey suit and just stand there saying nothing.

David

OK - I have been a bit distracted by some real-life things, but now I want to tackle all this by putting it into a slightly larger context.

We are talking about the origin of life, so what would the Earth look like prior to this wondrous event? It is customary to assume that a large quantity of organic chemicals formed on the Earth as a soup. It is also assumed that the components of this soup undergo chemical interactions prompted by heat from the sun, lightning flashes, or whatever. Chemists have some idea what such a soup would be like because many organic chemistry reactions produce a certain amount of 'tar' as well as some desired product(s). The tar is rarely interesting because it consists of chemicals just linked together at random. This is

Problem 1 - how do we end up  with a nice selection of biological monomers waiting to be coupled together?

OK, now suppose that somehow the first problem is resolved, and we have a nice soup of exactly the right chemicals to form life (think DNA bases, amino acids, sugar molecules), except that all the optically active chemicals are present as a 50:50 mixture of L and D forms - a racemic mixture. We still have the problem that any polymerisation will happen in an undirected way.

Remember that in life as we know it, enzymes, which are optically active, catalyse the creation of every biopolymer, but we can't create a coherent story for the creation of life if we assume we have components  that we don't yet have.

Polymerisation by heat or using crystal surfaces might be possible, but this will be utterly haphazard. All the monomers have multiple ways they can couple together, so the chance of ending up with a linear chain of (say) 100 units is incredibly small.Obviously, one of the problems at this stage is to use the

The fact that each of the monomers (with the exception of the amino acid glycine) comes in L and D versions is a severe problem because if a growing chain gets extended by the wrong optical isomer, the chain will become kinked and therefore biologically useless. There is no plausible way to make the primordial soup mainly of one set of optical isomers. This problem remains until polymerisation is controlled by enzymes which are themselves optically active.

Imposing a slight bias on the number of these isomers doesn't really solve the problem at all. Thus we have:

Problem 2 How do we get Biological polymers when there are so many ways these processes can be led astray?

Even after this step we have the biggest problem of all. You can synthesise as much DNA as you like, but unless it has useful codes, it will not do anything. Those codes need a master biochemist to work out a sequence of amino acid residues that would result in a useful protein and encode that in some DNA.

Problem 3 How do we get a useful code into the DNA?

There are still other problems, but let me point out one. Suppose by some gigantic fluke a single-celled organism were to appear in the soup. How is it supposed to survive? What will it eat, and won't it succumb to the many poisons that will be floating in the brew - cyanide for example.

I think life cannot be created without designer(s) of some sort, and that any such organism could not possibly evolve by RM+NS because as discussed previously DNA cannot evolve.

Even though I am not a Chistian, I must acknowledge that the work done by people in the DI has completely smashed the old, very vague concept of how life appeared and diversified on Earth.

David

You’re mostly restating earlier points without addressing the experimental evidence that homochirality can arise naturally via autocatalysis, long before enzymes exist. The idea that polymerization can’t happen without enzymes ignores the role of simpler catalysts (like minerals or metal ions) explored in origin-of-life research. As for information content in DNA, that's an evolutionary issue, not a chemical one. Natural selection operates on whatever replicators exist, no “master biochemist” required. These aren’t new problems, and they’ve all been explored in prebiotic chemistry literature.

It’s probably a good idea also to read other sources for information than Discovery Institute (just a suggestion), see for example https://www.asianscientist.com/2018/06/i...-polymers/

You’re mostly restating earlier points without addressing the experimental evidence that homochirality can arise naturally via autocatalysis, long before enzymes exist. The idea that polymerization can’t happen without enzymes ignores the role of simpler catalysts (like minerals or metal ions) explored in origin-of-life research. As for information content in DNA, that's an evolutionary issue, not a chemical one. Natural selection operates on whatever replicators exist, no “master biochemist” required. These aren’t new problems, and they’ve all been explored in prebiotic chemistry literature.

It’s probably a good idea also to read other sources for information than Discovery Institute (just a suggestion), see for example https://www.asianscientist.com/2018/06/i...-polymers/

You are utterly missing my point. Do you disagree with my list of problems associated with the transition from pre-biotic soup, and if you do, which ones are wrong and why.

David

You are utterly missing my point. Do you disagree with my list of problems associated with the transition from pre-biotic soup, and if you do, which ones are wrong and why.

David

I disagree with all of these points, they're variations of the classic “God of the gaps” argument, which the Discovery Institute and its followers continue to recycle. Your concerns about optical isomers have already been addressed. experiments have shown that homochirality in biological polymers can arise naturally through autocatalytic processes, given even a tiny initial imbalance. And frankly, we don’t know all the conditions on prebiotic Earth, so claiming to “disprove” what could or couldn’t have happened chemically over millions of years is not only speculative, it’s deeply naive.

I disagree with all of these points, they're variations of the classic “God of the gaps” argument, which the Discovery Institute and its followers continue to recycle. Your concerns about optical isomers have already been addressed. experiments have shown that homochirality in biological polymers can arise naturally through autocatalytic processes, given even a tiny initial imbalance. And frankly, we don’t know all the conditions on prebiotic Earth, so claiming to “disprove” what could or couldn’t have happened chemically over millions of years is not only speculative, it’s deeply naive.

Experiments have not "shown" this at all ~ it is simply presumed to be due to "natural" aka Darwinian and Materialist causes. In reality, there are no experiments that shown that it has happened ~ you would need an actual prebiotic soup and lots and lots of time to measure results. And as it stands... every experiment that tried to recreate the prebiotic soup just ends up with tar and a mix of left and right-handed amino acids.

And frankly, claiming to know what the conditions were on a prebiotic earth, and that a prebiotic soup was responsible for accidentally creating life from mere chemical reactions is also deeply speculative ~ not scientific in the least. There can be no evidence for it, because we cannot go back to the past ~ we can only speculate, based on so many vague crumbs that could frankly mean anything and everything. We cannot even know any context, so we effectively can have no answers.