Pop science and the basis of life

There is a… thing.

An exhaustive critique would be… exhausting.  But I can’t let this go completely untouched either.  So I’ll compromise with highlighting some of the most egregiously wrong parts.

Living systems are uniquely characterized by two-way flows of information…

Well, no. First of all, computers are also characterized by two-way flows of information, so the word ‘uniquely’ is incorrectly used. Second, life is well characterized in simpler terms by negentropy, or the ability to use energy to transfer entropy from itself to the surroundings and maintain a net negative entropy balance.

But since then, scientists aren’t much further along in understanding how simple amino acids could have eventually morphed into simple, and then complex, living beings.

The reason this field has not advanced in a while is because currently nobody really thinks that amino acids morphed into living beings. We have thought for some time that nucleic acids are more plausible candidates for early life. Nucleic acids have more plausible self-replicating mechanisms and are known to be capable of catalyzing chemical reactions just like protein enzymes. The field of RNA life, incidentally, has made substantial progress since the Miller-Urey experiments.

“Usually the way we identify life on Earth is always by having DNA present in the organism,” Walker told LiveScience. “We don’t have a rigorous mathematical way of identifying it.”

It’s possible that rigor is in the eye of the beholder here, but negentropy is a mathematical way of identifying life, and the presence of DNA is not considered indicative of life on earth since this would include the DNA viruses.

Using a chemical definition of life — for instance, requiring DNA — may limit the hunt for extraterrestrial life, and it also may wrongly include nonliving systems, for instance, a petri dish full of self-replicating DNA, she said.

If you had a sequence of DNA that could self-replicate (although RNA is more plausible for this), why would it be wrong to conclude that it is a living system? It’s definitely a grey-zone, but it’s more solidly on the life side than DNA viruses, for example. They complain about definitions of life that are too stringent, but if their definition really rules out something that faithfully self-replicates, I don’t think they have a leg to stand on in that regard.

Another hallmark of living beings is that they have different physical locations for storing and reading information. For instance, the alphabet of letters in DNA carries the instructions for life, but another part of the cell, called the ribosome, must translate those instructions into actions inside the cell, Davies told LiveScience.

Wildly unjustified criterion. Also- the catalytic site (read as- the business end) of the ribosome is composed entirely of nucleic acid (RNA- the same kind nucleic acid as the ‘instructions’ it reads).

But then, that article about chemistry they criticize is almost equally bad, talking about phosphorus with what I can only describe as reverence.

The evidence that phosphorus plays a unique role in the complex chemistry of life? Phosphorus comes in at #6 in the human body composition, but at a bare 17th in the elemental composition of the solar system. Lets look at the more abundant competition for a moment-

Noble gases: He, Ne, Ar

Metals: Mg, Fe, Al, Ca, Na, Ni, Cr

Forms only 1 covalent bond: H

Forms multiple covalent bonds: O, C, N, Si, S

Noble gases generally will not form any bond with anything. The metals on the list can contribute electrons to a bond, but they will happily float away after doing so. Sometimes hydrogen will do this, too. But even when it doesn’t, it can only form one bond- so it can terminate a polymer, but not continue it. Five of those elements can form a covalent bond with more than 1 other atom at a time- and so could participate in forming a polymer.

Yeah.  I really see what they mean… there are a whopping 5 possible polymer backbone elements more abundant in the solar system than phosphorus (two of which are also present in the phosphorus based backbone of DNA)- and yet phosphorus is the… 4th most abundant of those elements in the human body. And the ones more abundant than it all match abundance order in the solar system to abundance order in the human body. Yes. Clear evidence for the privileged role of phosphorus in the rise of life.

The phosphate (PO4) works as a kind of “super glue,” since it has three oxygen atoms that will carry charges in solution. Two of these oxygen atoms form ionic bonds with two neighboring sugars…

No. Stop. Find the closest chemistry textbook. It will tell you the ribose-phosphate bonds are covalent. Not ionic. You should have done this before writing anything. Also, the ‘super glue’ phosphate-ribose bonds are actually the easiest link in the nucleic acid backbone to break.

Not many molecules could perform this three-charge juggling act. Arsenate is one possibility.

Again, since it is not an ionic bond, charge has nothing to do with anything. Phosphate can bind up to 3 things covalently. Nitrogen can also do this. Carbon can also do this. Both of those elements do this in the context of life on earth.

Because of its vital role, all organisms on Earth must find a source of phosphorus.

This is true of every element in your body. No known organism can perform nuclear reactions, therefore all known organisms must have a source of every element of which they are made.

‘Reduced phosphorus is more chemically reactive than phosphate,’ Pasek said. This extra reactivity could have helped phosphorus sneak its way into the game of life billions of years ago.

Except that reduced phosphorus compounds don’t actually participate in the polymers or metabolic pathways that we use phosphorus for. Also, extra reactivity isn’t useful in a general sense- it can be useful for specific things, but ‘extra reactivity could have helped’ is utterly vacuous without proposing a some chemical pathway or other in which it could be useful. In fact, figuring out what to do with highly reactive compounds are one of the biggest problems your cells face on the molecular level and managing them improperly quickly kills the cell in question.

I’m not being hyperbolic when I say these articles contain more misinformation than information. And the most advanced criticisms above require no more than 1 chemistry class beyond basic high-school proficiency. Some of it is grade-school level. Experts at that level are not hard to find.

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