Nick Lane --The Vital Question, Post #2 -- June 12, 2019

This was the first post regarding this book. Read this post first.

Re-reading the book a second time, noting the key points that need to be re-emphasized.

Nick Lane is advocating a position. Some scientists frown on advocating a position (p. 14).

Nick Lane provides an argument: how complex cells came about and peculiar properties of complex cells; "what" defines a complex cell.

First point: there was no gradual evolution toward a complex cell. There was a singular event that resulted in a complex cell. I think Stephen Jay Gould would have liked that: long periods of equilibrium punctuated by abrupt change.

The singular event: an archeon (archaea) acquired a bacterial cell which ultimately became what we call the mitochondrion.

References Bill Martin, p. 11, who put this together through logic:
archeons need only H and CO2 to survive. That's it: H and CO2. Their biology would be geared toward converting H and CO2 to energy.

Meanwhile, versatile bacteria produced hydrogen.

Wow, wouldn't this be a great idea? Instead of the archeon depending on an external source of hydrogen, why not carry a source of hydrogen with it, wherever it goes.

Earth's atmosphere:
hydrogen: 1 ppm
CO2: 400 ppm

An archeon, which needed an exogenous source of hydrogen, acquired a hydrogen-making factory, a bacterium with a different chemistry than itself.

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Second point: complex life arose once and only once because it was such a hard thing to do. No other examples of a different type of complex life.  There were no intermediate steps, no "missing links."  We had archea (archeons) and we had bacteria: two different "animals."

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Third point: good, bad, or indifferent, it's the method of energy production in a complex cell (archeon + bacterium ---> eukaryote) that results in the properties that define a "complex" cell. Sounds a bit circular, but that's only because of the way I describe it.

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Fourth point: energy system in complex cell -- proticity, not electricity. We'll discuss that later.

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What Nick Lane wants to answer in his book:

1. Lane wants to persuade the reader that energy is central to evolution.
1a. We can only understand the properties of life if we bring energy into the equation.

2. Lane wants to show us that this relationship between energy and evolution goes back to the very beginning.

3. Lane wants to show us that the origin of life was driven by energy flux; that proton gradients were central to the emergence of cells, and that their use [the use of protons] constrained both the structure of bacteria and archaea.
3a. These constraints dominated later evolution of cells, keeping the bacteria and archaea forever simple in morphology, despite their biochemical virtuosity.

4. Lane wants to prove that a rare event, an endosymbiosis in which one bacterium got inside an archaeon, broke those constraints, enabling the evolution of vastly more complex cells
4a. Lane wants to show that this was not easy -- and thus why it happened only once -- wow, Stephen Jay Gould would be interested in this ... right up his alley....

5. And then, Lane wants to persuade us that this intimate relationship actually predicts some of the properties of complex cells:

• the nucleus
• sex
• two sexes
• the distinction between the immortal germline and the mortal body -- the origin of a finite lifespan and genetically predetermined death

6. Finally: Lane wants to convince us that thinking in these energetic terms allows us to predict aspects of our own biology, notably a deep evolutionary trade-off between fertility and fitness in youth, on the one hand, and ageing and disease on the other