Why we even have to discuss that is beyond me. James Tour might be an amazing chemist, but his accomplishments are irrelevant. What matters is if James Tour can predict from first principles all possible forms of life. He can’t, he has not even attempted that.
The point here is that synthetic organic chemists understand process nature would have supplied to a small area for life to arise through natural processes.
They don’t. Look at all James Tour’s arguments, they’re either arguments from ignorance, or just assertions. Scientists are routinely surprised to find that some chemical reaction happens they didn’t expect to, or the other way around.
Next, I will comment on your initial attack on Dr. Tour’s comments regarding his opinion that life should not exist at all anywhere in the universe. His opinion is not unusual.
Facts aren’t settled by committee. Where has James Tour predicted what all possible forms of life are? Nowhere.
Perhaps you have not read the book Rare Earth: Why Complex Life is Uncommon in the Universe by Ward and Brownlee.
What’s interesting is that there are a lot of evolutionary biologists who would agree with that (that complex life is probably rare in the universe). Even I would agree with that. But how often complex life evolves is irrelevant to whether the laws of physics say that life can’t originate. Nobody has done any work to establish that.
I would highly recommend it to you. I know that there are some who think there must be thousands, perhaps millions, of planets teeming with life across the universe. This book explains why they are probably wrong.
The book makes no attempt to estimate the probability of life arising. It deals only with trying to estimate the requirements for complex, sentient animal-like life.
You also complained that Dr. Tour doesn’t know what the first life looked like. That’s true. But then neither do you.
Then we are done, really. James Tour’s conclusion can not be supported. You can’t say that something you don’t know the properties of cannot come to exist.
Your assertion that the earliest life forms could be much simpler than bacteria available for us to examine now could be true, but probably isn’t.
What do you base that on?
You have no evidence to present to show that it was simpler or even that it could be.
Actually I do. There is actually some evidence of a simpler stage of life. Not much, but it is there and can’t just be ignored. Hints from phylogenetics of a simpler time, before cells had evolved the biosynthetic pathways for making their own amino acids.
Inferences of ancestral nodes in the phylogenetic trees of the oldest (most widely conserved) protein sequences increasingly mirror the abiotic distribution of amino acids produced by nonbiological chemical reactions, as we go further and further back in time. That’s evidence right there that the earliest proteins were synthesized from amino acids that existed in the environment, and that the biosynthetic pathways for their synthesis subsequently evolved. The “modern” distribution of amino acids we see in extant proteins drops off the further back we go, and larger and more complex amino acids like Tryptophan become less frequent, while the simpler amino acids like glycine, alanine, valine and so on become more and more frequent. This trend converges on the same distribution expected from chemical thermodynamic calculations of the ease of their synthesis, the distribution observed in various carbonaceous chondrites, and mirrors the distribution also seen in various experiments in abiotic organic chemistry, such as simulated hydrothermal conditions, spark-discharge experiments and so on.
See:
Higgs PG, Pudritz RE. A thermodynamic basis for prebiotic amino acid synthesis
and the nature of the first genetic code. Astrobiology. 2009 Jun;9(5):483-90.
DOI: 10.1089/ast.2008.0280
Brooks DJ, Fresco JR, Lesk AM, Singh M. Evolution of amino acid frequencies in
proteins over deep time: inferred order of introduction of amino acids into the
genetic code. Mol Biol Evol. 2002 Oct;19(10):1645-55. DOI: 10.1093/oxfordjournals.molbev.a003988
Jordan IK, Kondrashov FA, Adzhubei IA, Wolf YI, Koonin EV, Kondrashov AS,
Sunyaev S. A universal trend of amino acid gain and loss in protein evolution.
Nature. 2005 Feb 10;433(7026):633-8. Epub 2005 Jan 19. Erratum in: Nature. 2005
May 26;435(7041):528. DOI: 10.1038/nature03306
Ask yourself, why should this trend be observed in amino acid gain and loss? Why would the frequency of nonbiologically produced amino acids increase the further we go back in time? If life originated by some sort of intelligent design, the designer could have made the first life to exist with basically any distribution of amino acids that the designer wanted. For example, the designer could have made the first life to exist with the exact same distribution of amino acids that we see in life that exists today on Earth in 2019. Why use fewer, and why use fewer by excluding the ones we see used more today? Why decide to mirror the abiotic distribution? A deceptive designer?
This is real data, and it’s evidence. It doesn’t allow us conclude much by way of inference about the earliest stages of life, except to say that the first proteins were apparently synthesized from nonbiologically produced amino acids. We don’t know the environmental, or even “cellular” context in which this evolution took place, we don’t know the genetic or membrane compositions of this stage of life (if any). There are countless things we don’t yet know. That doesn’t mean, just because we don’t know these things, that life couldn’t arise. Chemistry doesn’t say so.
I’m not here because I claim to know how life originates, or much about the aspects of a simpler form of life. I’m here to rebut the claim that it has been shown in chemistry that it can’t. Even if I couldn’t cite this evidence, that would only amount to increasing our ignorance. It wouldn’t make the origin of life less plausible, it would just make it more mysterious. Mysteries are not impossibilities.
Dr. Tour’s major complaint about the state of origin of life research is that OOL researchers are not abiding by the standards of science.
That is a remarkably broad and sweeping claim about an entire field. It’s also irrelevant to the matter at hand, which is Tour’s claim that we know from chemistry that life should not exist. No amount of personal or methodological failures by some OOL researchers can substantiate that conclusion.
They put together their reactions under changing conditions with both temperatures and atmospheric pressures changing drastically and quickly.
Some of them do, yeah. And they admit that such conditions are speculative. Some of them call them “plausible”, but we don’t have to agree. In any case, this simply isn’t true for all of them.
In addition, they obscure the fact
Obscure, as in deliberately hide? Have you contacted the journals that publish these papers to expose their fraudulent behavior?
they are performing very strict purification steps not possible in a natural setting and supplying very pure new chemicals in a just-in-time control.
All of which I agree, in so far as some of them do this, makes their experiments highly implausible. I also don’t buy some of these experiments, or the arguments invoked to make them appear “plausible”. But there’s a far cry from that to us being able to conclude that life should not exist, because chemistry.
These products are often highly reactive and would quickly become a mess if exposed to a natural environment. And perhaps of all, the researchers extrapolate their findings in ways the data do not warrant.
They certainly do. In all scientific fields, not just OOL research. Which is of course not good, but that doesn’t mean we can conclude that chemistry has shown that life should not exist.
Let me ask you a few questions. There are several approaches currently being studied: metabolism first, DNA first, RNA World, etc. Which of these approaches do you think is the best?
We don’t have enough information to make such evaluations at this stage. There are many issues I have with RNA (or worse, DNA first) research, some of which are actually mirrored in things James Tour says. But I just have to repeat myself then, that doesn’t mean we know from chemistry that life should not exist.
Which of these do you think has been falsified?
At this time, none of them. I only think we can make general statements about relative plausibility. Some are less plausible than others. We don’t know whether any of them are true, or any of them are false. We don’t have enough information to make such statements with any sensible degree of confidence.
