As I said I would, I’m watching this History Channel documentary about the origin of life. How about a little live-blogging?
8:00. Ugh. It begins with a bunch of tripe from Coyne and Polkinghorne, claiming we need religion to understand the meaning of life. This is a bad, bad start, but I’m hoping it’s nothing but a weasely preliminary that they will then abandon to get to some real science.
There are lots of gimmicky special efects, but OK, let’s get the general audience interested. I’m not too keen on the parade of talking heads, though: they keep trotting out different investigators, letting them say a sentence or two, and then zipping off elsewhere. I know you don’t want some guy sitting and droning at you, but this seems like a poor compromise.
8:15. It’s a quick tour of the complexity of the cell. They’re using this special effects analogy of a “factory of life” where chemistry is going on.
First important element of life: metabolism. Second: life is cellular, with compartments. Third: life can replicate.
Now we get a parts catalog of polymers: lipids, proteins, and nucleic acids.
Very weird: in their factory analogy, they point to something hidden behind a big red curtain and say that that’s where all these bits and pieces come together to make something that’s alive; it seems a bit of a cop-out, a way to pretend there’s something hidden where the viewer can imagine anything they want. Come on, bite the bullet and admit it: life is chemistry, and there is nothing more.
Now we get a fairly lengthy discussion of the idea of emergence. At least they clearly state that emergence is nothing magical, but is just a consequence of the execution of the laws of nature. This is a rather pointless digression, I think.
OK, now we get a timeline of the origin of life: it appeared about 3.8 billion years ago, on a very hostile planet with no oxygen in the air, and just cooling after the last of the great meteor bombardments. This leads naturally into a discussion of extremophiles, with a tour of Mono Lake.
Segue to commercial by mentioning that life will change the environment of the earth.
8:30. Conditions on early life are hostile to us, but chemical energy is abundant. Life would have existed as single-celled forms only, which may have been unrecognizable to us (why are they showing video micrographs of nematodes while they tell us this?)
Stromatolites are introduced, as organisms that grew on chemical energy sources. What are those energy sources?
The camera crew goes spelunking. They’re collecting rock-eating microbes, which the scientists argue is a kind of primitive chemistry that evolved before photosynthesis.
Nice reminder that single-celled life was the only form of life here for 80% of the history of earth, but then they make the mistake of using the past tense in saying they were the dominant form of life on the planet.
Wait…now they’re saying that the ability to reproduce is a property of DNA? That’s kind of cutting off the possibility of an interesting discussion of alternative paths.
Suddenly, boom, they’re talking about Leeuwenhoek. Hang on, this is a bit jumpy. Can we talk more about extremophile chemistry before we start on 17th-18th century microscopy?
Now it’s all about photosynthesis. We’ve moved way, way beyond the period of early abiogenesis already, and they’ve scarcely touched on any of the major theories.
Before the commercial, we get talk about multicellularity and oxygen chemistry. Either they’re going to be jumping about an awful lot and scrambling the story, or we’re not going to get anything about abiogenic chemistry…
8:45. Oops, I had to miss part of this section to run some real-world errands. I come back to see the Burgess Shale and a discussion of the Cambrian explosion. This is long, long after the origin of life!
It’s an excuse to show some computer animations of Anomalocaris, anyway.
George Coyne does a good job now saying that life doesn’t need a designer; Polkinghorne pops up to make excuses for the metaphorical nature of the book of Genesis. Bugger off, Polkinghorne, you bother me, ya twit.
Now we get a summary of the importance of selection and sex. I don’t think we’re going to get a good review of biogenesis anymore — sex is not an important issue in that field.
I am completely baffled. Before the commercial, they say the big question was how human life arose…then they ask, “What was the specific mechanism that caused non-living chemistry into living biology?” Weird. These are very different questions. They seem to be muddling up the origins of life with the origins of the only important form of life, humans.
9:00. We’re back to animals. Come on, animals are peculiar latecomers.
Maybe it’s an excuse to return to a historical survey of ideas about the origin of life. I hope.
Aristotle proposes the idea of spontaneous generation, an idea that hangs on for centuries but is relatively easy to disprove…as Redi and Spallanzani do. This stuff isn’t bad, but it feels like introductory material they should have brought up at the beginning.
Actually, I’m enjoying this part best of all so far. They’re actually talking about the experiments done to disprove spontaneous generation, so it’s a useful summary of how scientists actually do science.
Our closing question: so how did life arise from chemistry? The second half is off to a good start, I think.
9:15. I’ve got to say…the actor playing Charles Darwin looks nothing like him, and that beard looks cheesy and fake.
We get the early concepts: “warm little pond”, “primorial soup”. There the questions are about what kind of chemicals and conditions existed at the beginning of life. They mention Oparin’s ideas about the chemical monomers available, and the idea that these chemicals would accumulate in the oceans. It seems like a very low probability sort of exercise.
The Miller/Urey experiment at last. This is well done, with a very nice illustration of the apparatus and techniques. They get it right, too — it was nice work that showed that the natural chemistry that would produce organic substrates for life was relatively trivial. It also set up unrealistic expectations for how easy it would be to create life.
Closing premise: now there is a race to figure out prebiotic chemistry.
9:30. Let’s consider other sources of organic matter!
Space-borne debris. Complex organic molecules are found in metorites and in space. We get to see scientists extracting organic molecules from ground-up meteorites. Panspermia is mentioned, but they aren’t doing a good job of distinguishing chemicals from life. At least Bob Hazen is razor sharp in pointing out that panspermia is a cop out.
Hazen also clearly explains bottom-up (exploring basic principles about biochemistry to replicate the events at the origin) vs. top-down (working in reverse from extant life backwards to the origin). He also explains that we need a multiplicity of approaches, and the origin may also have been generated from diverse sources.
Hmm. Commercials seem to be coming more frequently as we get close to the end.
9:40. It’s deep-sea vent time, with nice shots of black smokers and squid. Then Bob Hazen shows us how his experiments on the chemistry at high pressure and temperature are done. Cooking a little pyruvate for a while generates substances that form micelles.
Clays! Clays are shown as potential catalytic surfaces that would concentrate organic compounds and promote reactions that form, for instance, RNA. RNA monomers will polymerize in the presence of clays.
Transition: are scientists on the verge of creating artificial life in the lab?
9:50. It’s “3000 years after Aristotle”? What?
Never mind. Now we get pretty crystals growing and changing. This bit is a little fluffy.
All right: Jack Szostak. They describe his efforts to try and create a protocell. Cool video of creating cell membranes — beautiful little droplets bubbling out of an electrode. Some good cautionary statements: if they succeed, this will still only be a model, not a demonstration of how it actually happened 3.8 billion years ago.
They don’t really say much about the mechanisms in the closing minutes, but they do have a nice statement by Neil de Grasse Tyson about how the search is the important thing, even if we don’t get an answer.
Summary: the first hour was a muddle, and not worth watching. If you’re going to catch it later, just watch the second half.
The last half wasn’t bad. It at least talked very briefly about the actual science and how it is done. It was all painfully abbreviated and only touched lightly on the subject, but I think that is simply a limitation of the medium. I imagine it’s a seriously difficult balancing act to try and meet the needs of real nerds (like us!) and the more casual viewer, so I’ll accept the compromise.
Something at the end to lead the interested viewer to more in-depth sources would have been a good idea — they could have at least mentioned Hazen’s Genesis as a plug.