All right then. I watched the entire James Tour talk, brought to us courtesy of the Discovery Institute.
Boiled down, the substance of the 1 hour talk is an argument from incredulity. In effect, Tour argues that "I can't think of how nature could have combined chemicals in such a way as to start life. Therefore it is impossible."
Tour never really engages with the question of whether a series of small steps could have led to the chemical construction of a simple living cell. Instead, he assumes that the very first life must have had the same level of complexity as all modern life. His argument is that because modern cells, carbohydrates and so on are complicated and varied things, it is extraordinarily unlikely that they could have arisen through any purely chemical process (i.e. one not requiring the prior existence of living things to "help" with the assembly).
Here are my rough notes of some of the things he discussed, with my comments on a few of them.
These are modern cells he is talking about. He never engages with the possibility of simpler cells, such as might have existed in the earliest lifeforms.
- False claim that non-living molecules have never been shown to "move towards order and life" without the help of living molecules.
Although he discusses many experiments that show the formation of various precursors of life, Tour still makes the claim that chemical processes never "move towards life" without help from human agents or pre-existing life. This is a false claim and he knows it because he specifically refers to the literature that disproves his claim.
- Talks about homochirality as if this is needed in advance of life.
This was a strange comment. Essentially, Tour claims that life requires homochiral molecules. My own understanding is that this was most likely an accident of evolution. Things could have easily ended up with the opposite chirality preference.
- Complains that chemical processes don't have a targeted goal to aim for.
Tellingly, Tour falls into an old Creationist trap with this comment. He takes a teleological view of life. To him, life must have an end goal in sight from the start. The first cells must somehow have known that they were "aiming" to create human beings somewhere down the line. Of course, in evolution there are no such goals.
Interestingly, I note in passing that Tour is careful in his talk not to emphasise the enormous tracts of time available for abiogenesis. At one point in his talk he slips up a bit and admits that the world is millions of years old at least, rather than the 6000 year age generally approved by his audience.
- Thinks that "purification" of chemical intermediaries is necessary at various points.
- Complains that things won't react in the correct order to make life.
- Complains that precise conditions are needed to make the relevant reactions go.
- Complains that not enough can be made without "going back to the beginning" to add material.
In all of this, Tour ignores the scale of the chemical experiment that was taking place on the proto-earth. The entire planet was one big chemical soup. Tour downplays the time and the space available for the necessary conditions to come about. At the same time, I think he most likely overplays the complexity involved. Caveat: I am not an organic chemist, but then again only two people in his audience of several hundred people willing to pay for a Discovery Institute sponsored event identified themselves as such.
- Sort of irreducible complexity argument - "if you do one thing wrong, it doesn't work"
At the start of his talk, Tour explicitly says he doesn't want to talk about Intelligent Design or the bible. By the end of the talk he has injected ID by stealth and he forgets completely about what he said about not mentioning the bible.
Here, in the middle, he grabs a play from the usual Creationist grab bag, arguing that cells, carbohydrates or lipids (I forget which) are effectively "irreducibly complex". In support of this idea, he then spends quite a long time heading down the path of merely counting the total number of possible random combinations of chemicals. In the process, he apparently forgets everything he knows about how chemistry constrains which of those random arrangements is more or less likely to occur.
- carbohydrates are complex
- interactomes are complex
Tour spends a lot of time in his talk trying to dazzle his audience with chemical jargon that he knows they won't understand, emphasising how complicated the chemistry of life is and how none of his scientific peers know what they are doing when they do work in the field of life origins. He's the only true expert, apparently. It's easy to do this when your audience is a lay audience containing next to no experts in his particular field of expertise.
- counts total number of possible permutations of various combinations of smaller units (e.g. carbohydrates). But this assumes they come together randomly.
I've already mentioned this one above. Somebody really ought to remind Tour that chemistry isn't random, because apparently he's forgotten that by this point in his talk.
- information: complains that information can't be created (e.g. an order of molecules or bases in DNA).
As soon as a speaker at a Creationist conference mentions the word "information" in reference to DNA or RNA, alarm bells ought to start to ring, because its a common Creationist lie that evolution cannot and does not create new information. Tour, without actually saying this in so many words, gives a dog whistle to Creationists in the know at this point in his talk. Of course, he doesn't actually back up his claim with evidence.
- complains that information changes over time.
This one is a bit odd, since most of his argument is based on what he says is the inability of chemicals to form the right structures to make life. Here, I think without realising it, he admits that lots of different structures are viable in certain living chemicals, like carbohydrates. Any of them would be suitable for life. However, he takes the opposite tack and tries to argue that variety is a negative here instead of a positive.
- complains that, currently, chemists can't synthesize cells, but admits it might be done in future.
No comment necessary, really. Tour's entire argument boils down to "making cells from chemical precursors is hard". Since he can't imagine how nature did it, he concludes that it can't be done. He also spends a lot of time attempting argument by ridicule, which must endear him to his colleagues. But at this point in his talk he lets slip that maybe chemists will eventually succeed in making cells artificially from scratch.
If chemists can do it in such a relatively short time, it would seem natural to wonder about what nature might achieve given an entire planet and hundreds of millions of years.
- Attempts argument by ridicule of a Nobel prize winner (Jack Szostak).
This part of the talk is probably the low point. Tour makes a personal attack on Szostak, at one point flat-out saying that he lied in scientific papers. Reading up on this, I find that Tour claims that he later apologised personally to Szostak for his comments, admitting that he went too far. Certainly, Tour has publically retracted his claim that Szostak lied.
Tour concludes with some general claims and comments:
- Says that scientists mislead the public about how much progress has been made in origin of life chemistry.
This has the whiff of conspiracy thinking about it, and at the end of the day Tour provides nothing much to back up his claim in this talk. No doubt it went down well with his Creationist audience. To make them even happier, Tour ends with a comforting lie:
- Claims there is no discordance between scientific facts and statements in the bible.
and, of course
- closes with a bible quote.
If there was any doubt about Tour's religious motivations at the start of his talk (which there really wouldn't have been given the circumstances of the talk itself), it is erased by the end.
To summarise then, I return to where I started. Tour's argument in this talk is an argument from incredulity. Tour can't imagine how life arose naturally from non-living chemical precursors, so therefore he argues that it is impossible. One motivation for making that argument, and more generally from going on the Creationist speaking circuit, is undoubtedly Tour's personal religious views.
