54
4 Life Evolves
chemical activity overcomes the coarsening tendency (Sect. 2.5) and leads instead
to cycles of growth and division (Fig. 4.7).
The great successes of genetics diverted attention from Oparin’s scenario, rendering it all but obsolete, but it was forcefully and controversially supported by Lynn
Margulis (1970). She believed RNA to be a parasite invading an already working
cell and taking control. Her views were propped up by Freeman Dyson, an outstanding theoretical physicist and an eloquent writer. Notably, nonconformism and
love of freedom were behind this penchant. Dyson (2004) expresses this openly: I
happen to prefer the Oparin theory, not because I think it is necessarily right but because it is unfashionable. The rule of the “selfish gene”, as it was famously dubbed
by Richard Dawkins (1976), caring only for its own perpetuity, is reminiscent of
political oppression, of invaders turning into rulers. This happened more than once
in history, like Scandinavian raiders subduing a Slavic land, “rich and and plentiful
but lacking order”, known ever since as Rus’, or Russia, from the name of the invading band, or, moving West, acquiring and renaming Normandy before subjugating
England from this base.
Personal preferences are, of course, not proofs. Dyson (1982) developed a toy
mathematical model of an Oparin-style self-sustaining metabolic system, though it
was less elaborate and persuasive than Eigen’s theory of autocatalytic cycles. Rather
naively, Dyson suggested that chemists might imitate Eigen’s experiment with a
self-generated population of RNA molecules (Eigen et al, 1981), starting instead
with combinations of catalysts and metabolites in a droplet and seeing whether it arrived at a lasting homeostatic equilibrium. In parallel, he suggested an accompanying simplification experiment, starting with a cell and seeing whether its metabolic
network would degrade if placed in a pampering environment. This would be a
counterpart of the experiment by Spiegelman (Mills et al, 1967) aimed at answering the question: What will happen to the RNA molecules if the only demand made
on them is the Biblical injunction, multiply, with the biological proviso that they do
so as rapidly as possible? It all came to “Spiegelman’s Monster”: a shorter chain
replicates faster, and evolving RNA got rid of one nucleotide after another, eliminating 83% of the original genome. Dyson’s idea was hardly practical, and nobody
followed it; chemists and biologists hardly ever take theorists’ advice, because they
know what they are able to do, and often come upon important results by sheer
luck. Oparin’s scenario in its original form is unlikely; it is more plausible that dividing protocells contained RNA replicating without the help of any proteins – but
the verdict on the modern “chicken or egg” dilemma is still out.
Margulis’ idea of an invader turning into a symbiont gained acceptance on another evolutionary level. The first organisms, like contemporary bacteria and archaea
(two branches of the phylogenetic tree in Fig. 4.1) were prokaryotes, with simply
structured cells that didn’t have interior membranes and organelles (Fig. 4.8). All
multicellular organisms, as well as some bacteria, amoebae, and slime molds, are
eukaryotes with nuclei and mitochondria separated by membranes of their own.
Nuclei contain chromosomes, so named just because they can be colored by certain chemicals in the lab. The nucleus is the command center of the cell where the
genetic information is stored and wherefrom instructions specifying the synthesis
4 Life Evolves
chemical activity overcomes the coarsening tendency (Sect. 2.5) and leads instead
to cycles of growth and division (Fig. 4.7).
The great successes of genetics diverted attention from Oparin’s scenario, rendering it all but obsolete, but it was forcefully and controversially supported by Lynn
Margulis (1970). She believed RNA to be a parasite invading an already working
cell and taking control. Her views were propped up by Freeman Dyson, an outstanding theoretical physicist and an eloquent writer. Notably, nonconformism and
love of freedom were behind this penchant. Dyson (2004) expresses this openly: I
happen to prefer the Oparin theory, not because I think it is necessarily right but because it is unfashionable. The rule of the “selfish gene”, as it was famously dubbed
by Richard Dawkins (1976), caring only for its own perpetuity, is reminiscent of
political oppression, of invaders turning into rulers. This happened more than once
in history, like Scandinavian raiders subduing a Slavic land, “rich and and plentiful
but lacking order”, known ever since as Rus’, or Russia, from the name of the invading band, or, moving West, acquiring and renaming Normandy before subjugating
England from this base.
Personal preferences are, of course, not proofs. Dyson (1982) developed a toy
mathematical model of an Oparin-style self-sustaining metabolic system, though it
was less elaborate and persuasive than Eigen’s theory of autocatalytic cycles. Rather
naively, Dyson suggested that chemists might imitate Eigen’s experiment with a
self-generated population of RNA molecules (Eigen et al, 1981), starting instead
with combinations of catalysts and metabolites in a droplet and seeing whether it arrived at a lasting homeostatic equilibrium. In parallel, he suggested an accompanying simplification experiment, starting with a cell and seeing whether its metabolic
network would degrade if placed in a pampering environment. This would be a
counterpart of the experiment by Spiegelman (Mills et al, 1967) aimed at answering the question: What will happen to the RNA molecules if the only demand made
on them is the Biblical injunction, multiply, with the biological proviso that they do
so as rapidly as possible? It all came to “Spiegelman’s Monster”: a shorter chain
replicates faster, and evolving RNA got rid of one nucleotide after another, eliminating 83% of the original genome. Dyson’s idea was hardly practical, and nobody
followed it; chemists and biologists hardly ever take theorists’ advice, because they
know what they are able to do, and often come upon important results by sheer
luck. Oparin’s scenario in its original form is unlikely; it is more plausible that dividing protocells contained RNA replicating without the help of any proteins – but
the verdict on the modern “chicken or egg” dilemma is still out.
Margulis’ idea of an invader turning into a symbiont gained acceptance on another evolutionary level. The first organisms, like contemporary bacteria and archaea
(two branches of the phylogenetic tree in Fig. 4.1) were prokaryotes, with simply
structured cells that didn’t have interior membranes and organelles (Fig. 4.8). All
multicellular organisms, as well as some bacteria, amoebae, and slime molds, are
eukaryotes with nuclei and mitochondria separated by membranes of their own.
Nuclei contain chromosomes, so named just because they can be colored by certain chemicals in the lab. The nucleus is the command center of the cell where the
genetic information is stored and wherefrom instructions specifying the synthesis