Tag Archives: Molecular biology


How Molecular Forces and Rotating Planets Create Life Jan Spitzer

I thought I understood a thing or two about biology, and, more specifically, its genetic and general molecular side as well. I’ve read a couple of introductory level university course textbooks, like Biology, Evolution and Human Nature by Goldsmith & Zimmerman (2001), which was already pretty heavy on chemistry for somebody without an academic background in hard sciences, and a few more specific books, like the excellent The Flexible Phenotype by Piersma & Van Gils (2011) and Alex Rosenberg’s brilliant, rigorous Darwinian Reductionism, Or, How to Stop Worrying and Love Molecular Biology (2006).

I also thought I had a bit of grasp on origin of life theory, since I read Nick Lane’s excellent The Vital Question: Energy, Evolution and the Origins of Complex Life (2015), a book I can’t say I understood completely, but enough so to enjoy it a lot.

Last year, I was absolutely gobsmacked by Contingency and Convergence: Towards a Cosmic Biology of Body and Mind by Russell Powell, a 2020 publication in the Vienna Series of Theoretical Biology, and so when I checked what else was published in that series, I didn’t hesitate to buy How Molecular Forces and Rotating Planets Create Life: The Emergence and Evolution of Prokaryotic Cells by Jan Spitzer – I was intrigued by the subject matter because of Lane’s book, and if I’d survived that, how hard could it be?

Well, it turns out this was harder, much harder, yet I probably enjoyed it even more. Part of that enjoyment is witnessing other people’s genius, but the main reason I enjoyed it so much was because it provided entirely new and much more detailed insight in the miracle that is our existence.

Before I get to a more detailed discussion of the book, please consider the following drawing – a typical representation of a bacterial cell I found somewhere on the public domain.

prokaryote cell

This is the way most people are taught about cells. We tend to think we *understand* cells this way – at least, if we study some more of these drawings – including ones that zoom in a bit – and the accompanying chapters on cell biology carefully.

Now consider this fragment from Jan Spitzer’s book, and, for starters, compare the way the cytoplasm is represented in the generic textbook drawing with what Spitzer writes about it.

From a purely chemical point of view, a bacterial cell is exceedingly complicated. The cytoplasm contains in round numbers ~2,500,000 protein molecules of ~1,000 different kinds, ~200,000 transfer RNAs of ~50 kinds, ~1,500 short-lived messenger RNAs of ~400 kinds. (…) The number of ribosomes can vary between 2,000 for a slow-growing population and 70,000 in a fast-growing population. These biomacromolecules are hydrated by a relatively concentrated (~4%) electrolyte – a multicomponent buffered solution of simple ions, particularly potassium ions and phosphate, and other low-molecular weight metabolites from biochemical pathways (…). All this chemistry of long DNA double helices (partly condensed or coacervated by cationic proteins and amines), RNAs, and their protein complexes, all in their correct three-dimensional conformations, and all exhibiting their molecular motions – from bond rotations to large conformational motions and rotational and translational Brownian diffusion, taking place on timescales of many orders of magnitude, from femtosecond infrared motions to physiological motions at milliseconds, seconds, and hours – all this molecular motion is crowded and enclosed within the hydrophobic cell envelope. The cell envelope contains a lipid bilayer membrane, studded with a large number of integral hydrophobic proteins that sense the physicochemical state of both the external nutrient environment and the internal cytoplasmic side of the membrane and adjust the molecular and ionic traffic across the membrane accordingly. (…) The overall chemical system is in cyclic disequilibrium, where cells approximately double in size and then divide on the physiological timescale of seconds to hours.

Additionally, in all this, also the positions of all those different molecules matter, as there is no “bulk aqueous reservoir where chemical potentials (concentrations) are independent of position”, and so the cell system is “thus vectorial”, with aqueous nano-channels and nano-pools of dissolved ions and molecules.

It is yet another example of the huge gap that exists between what people – even highly educated people – think they know, and how the world actually is. It makes books like Spitzer’s humbling and full of wonder – even if that wonder is abstract, dry, and highly complex. Do we truly appreciate the wonder of life enough?

There’s one important caveat: however detailed that quote might seem, it only scratches the surface too. Or, to quote Spitzer again: “Today the molecular crowdedness of a living cell is an uncontroversial and well-appreciated fact, but its overall spatiotemporal complexity remains poorly understood.”

Just to be clear: I’m not the target audience for Spitzer’s book. Certain parts – when he got into the nuts and bolts of detailed chemical stuff – were way too advanced for me. I’d say about 1/3rd of the text was too technical for my current brain. But that doesn’t mean I couldn’t understand Spitzer’s general message – it only meant that I could not contradict him on the technicalities. The fact that the main text is only 170 pages, but about 1/3rd of the full volume is academic credentials (20 pages of notes, 26 pages of references, a 5 page index) is indicative of its intellectual rigorousness.

I think one of the reasons that makes this book successful is that Spitzer approached it as a hobby. He has had no academic career in biology, but he is a physical chemist (PhD) and a chemical engineer (MS) with expertise in thermodynamics and aqueous colloids, who worked as a industrial R&D manager, on synthetic latexes and emulsion polymerization processes. The fact that he is retired and has no skin in the game allowed him to write freely and thoroughly. More information on Jan Spitzer and his ideas can be found here.

In the remainder of this text, I will try to summarize Spitzer’s main points, and conclude with a list of quotes & fragments of knowledge that struck me and that I wish to keep record of. Most of those should also be worthwhile to readers with an advanced interest in science, but you might need a dictionary depending on your prior knowledge – I know I needed one. As a coda, there’s a shortened version of a reading list Spitzer himself provides in his introduction.

For a review by someone with an academic background in these matters, I refer you to the Small Things Considered blog. It has a good, fairly detailed outline of the book. It is the only review of the book I found online, so I hope I contribute a bit to Spitzer’s dissemination with my own review – especially for those that are looking for more information about it without easy access to academic libraries.

Do I recommend it? I loved it, but if you’re not academically trained in these matters ymmv, so much is clear – if you’re adventurous, like a serious challenge, and want to keep your mind limber, go for it, I’d say. It’s also crystal clear that this is mandatory reading for anybody with a serious academic interest in the matter.

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DARWINIAN REDUCTIONISM – Alex Rosenberg (2006)

Darwinian Reductionism

Darwinian Reductionism, Or, How to Stop Worrying and Love Molecular Biology must be one of the toughest books I’ve read. Luckily, it’s fantastic.

Alex Rosenberg is a professor of both Philosophy and Biology at Duke University. He has written about the philosophy of science before, like a book about the non-validity of economics as a science. Rosenberg is a true intellectual powerhouse, and to watch his mind work over the course of this book’s 238 pages (+ about 30 pages of references and index) is one of the pleasures of reading this book.

Kim Sterenly sketches what it’s about on the back cover:

“Over the last twenty years and more, philosophers and theoretical biologists have built an antireductionist consensus about biology. We have thought that biology is autonomous without being spooky. While biological systems are built from chemical ones, biological facts are not just physical facts, and biological explanations cannot be replaced by physical and chemical ones. The most consistent, articulate, informed, and lucid skeptic about this view has been Alex Rosenberg, and Darwinian Reductionism is the mature synthesis of his alternative vision. He argues that we can show the paradigm facts of biology – evolution and development – are built from the chemical and physical, and reduce to them. Moreover, he argues, unpleasantly plausibly, that defenders of the consensus must slip one way or the other: into spookiness about the biological, or into a reduction program for the biological.”

But for many people, including scientists, there are problems with materialistic reductionism, as Elliot Sober explains on the back cover, before pointing out how Rosenberg tackles those problems.

“For most philosophers, reductionism is wrong because it denies the fact of multiple realizability. For most biologists, reductionism is wrong because it involves a commitment to genetic determinism. In this stimulating new book, Rosenberg reconfigures the problem. His Darwinian reductionism denies genetic determinism and it has no problem with multiple realizability. It captures what scientific materialism should have been after all along.”

I will not get into the nuts and bolts of every argument. Aside from a general appraisal of the book, I’ll elaborate a bit on two small – yet fundamental – elements of critique, and end with a list of nuggets of wisdom I found while reading – a list that is probably of interest to those readers not interested in the general content of this book, yet who do have a healthy interest in science.

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