The point I first responded to was whether “we have a decent idea of some of the basic hardware a self-replicating cell will require.”. And I am giving an example of how we could get transport across a primitive cell membrane to work without requiring complex protein machinery to do it. That is the whole point here, that those complex machines aren’t required at these simpler stages. The kinds of molecules that would get in and out are small ions and monomers, and the internal and external concentrations are driven by primitive physical mechanisms instead.
But at the time you gave me (28 minutes) Tour is talking about whether the kinds of chemistry some have proposed to form nucleotides could plausibly occur on magnitudes large enough to yield high concentrations of nucleotides. I’m going to skip that because it’s just not relevant to what I was saying.
At about 30:00 Tour goes on to give various complaints about work in primitive cell membranes, many of which are highly dubious and might simply not be of any relevance to the origin of life, and I couldn’t possibly be bothered to go through them all here. But what can be said about most of them is that they in effect all constitute red herrings.
Tour is taking it as a given that, since modern cells HAVE those structures, these MUST be spontaneously formed at the origin of life somehow, otherwise he appears to basically consider the research irrelevant.
To see an example of how he does this, he says at 30:46: “Every experiment uses just homogeneity throughout the whole thing, and so it isn’t, isn’t really a protocell, it’s not reminiscent of a cell”.
Disregarding that the assertion is flat out false(many experiments have been done with complex lipid mixtures), I have to ask, why not? Why is it not a protocell just because it doesn’t fully resemble a modern cell in all aspects? Why does it HAVE to be reminiscent of an extant cell? Isn’t that the whole goddamn point of a proto-cell? Something that came BEFORE the modern cell, that evolved into modern cells as we see them? Cells that began simpler and then became more complex over time?
Once you notice this, you see he does it everywhere. He appears to dismiss all the research being done as not relevant(he calls it “garbage”) in his mind because the kinds of things researchers are producing don’t look like cells with 4 billion year evolutionary histories. No shirt?
He gets away with dismissing lots of research out of hand because it doesn’t produce modern cells. But it’s not supposed to produce modern cells. The questions researchers are seeking to address is if simpler cells than modern cells are possible, and if they are, how could these simpler come about and how would they work? Cells that don’t have thousands of lipids and membrane transport machineries, don’t have complex chains of carbohydrates extending from their membranes, etc. etc.
Modern cells are the results of approximately 4 billion years of evolution by natural selection. Is it really any surprise that these are different and more complex from what researchers are trying to determine how could have emerged and function at the origin of life? Many of these systems we are all deeply fascinated by, evolved subsequently to the origin of cellular life. Some later than others. But obviously it makes more sense to explore a hypothesis that life began at a state of cellular complexity much simpler than we currently see. That is basically the hypothesis being explored in this research.
At 30:23 he gives a list of things modern cells use lipids for, and mentions for example subcellular organelles such as the eukaryotic nucleus and mitochondria.
Pardon me, but eukaryotes and mitochondria came roughly 2 billion years after the origin of life, why even mention these? They’re the product of evolution. By the way, mitochondria are derived from bacteria, they have bacterial cell membrane lipids. Tour goes on to insist nobody knows how mitochondria or the nucleus obtained their lipid compositions. This is extremely misleading, and really just reveals Tours vast ignorance on research into evolutionary history and the origin of eukaryotes. I still have to wonder why he even brings these things up, they’re eukaryotic characters. Life did not begin with eukaryotes.
It’s like complaining that prebiotic chemistry doesn’t produce lungfish, and then acting all surprised and dismissive since now the origin of life doesn’t explain lungfish. Come on dude!
Finally at 31:30 tour comes to talk about the transport machines and how these are required in modern cells, because in modern cells the phospholipids yield an impermeable membrane that does not allow anything to leave or enter the cell. I know, that’s the whole point. If the cell is NOT made of modern phospholipids, but a dirtier mix of simpler, more prebiotically plausible amphiphilic molecules like fatty acids and fatty alchols, the sort of membrane these can form DOES allow passive ion and small molecule transport across the membrane. One could go on and on with Tour being dissatisfied that work on protocells and primitive cell membranes do not produce modern cells that can do all the things modern cells can do. And I just have to ask, why should we think it has to? The point of the research is to explore whether simpler systems can function in principle, and if so, how they could emerge. The work isn’t over by any stretch of the imagination, but many of Tours theatrically delivered concerns make zero logical sense.