Life's origin is enigmatic in part
because, as Aharon Katchalsky, the promising young thermodynamics researcher,
put it, we "knew" that life originated spontaneously from
nonlife, then we "knew" that it didn't,
and now we know, in a different way that it did. An organizer of an international
symposium on irreversible thermodynamics and the origin of life, Katchalsky
spoke of "a dialectic cycle starting with the thesis—the belief
in spontaneous generation—followed by the antithesis—which
negated any inanimate origins, based on the work of Francesco Redi, of
Spallanzani, and culminating in the brilliant studies of Pasteur—and
finally leading to the modern synthesis initiated by Oparin and Haldane.”
The conference included luminaries from both thermodynamics (Morowitz
and Prigogine) and origins-of-life research (Elso Barghoorn, who at that
time had found the oldest microfossils, and Faustian experimenters Leslie
Orgel and Stanley Miller). Katchalsky was assassinated in the Tel-Aviv
Airport in a massacre May 30, 1972, soon after. But at the conference
he quoted Darwin who, in early editions of On the
Origin of Species seemed
to flirt with the idea of a divine start to evolution, which could then
grandiosely unfold, like Newtonian clockwork, throughout vast stretches
of time:
But if (and, oh, what a big if!) we could conceive
in some little warm pond, with all sorts of ammonia and phosphoric
salts, light, heat, electricity etc., a protein substance was created,
capable of experiencing further more complex transformations—then
at present time such a substance would have to be consumed or absorbed;
which could not happen in the period preceding the formation of
living creatures.
"Darwin," exulted Katchalsky, "was therefore aware that
a physico-chemical evolution preceded the biological and it is this evolution
which may escape the criticism of the antithesis." Life's origin
from inanimate things was a big idea, one Darwin himself was barely ready
for. But there it was, made scientifically plausible again by the idea
of evolution. One is reminded of Mary Shelley's gothic portrayal of the
Frankenstein monster's electrical animation, of Michelangelo's heavenly
father touching Adam on the ceiling of the Sistine Chapel. There is something
magical, incredible about the instantaneous energizing of life. And these
are still Western notions, based on history and the notion that time
and separate identity is real. But in Eastern philosophy, Hinduism for
example, the world, Brahman, is alive: you are not born into it but come
out of it, like fruit on a tree, the Atman or self sometimes realizing
its true nature before dying and being reborn—or escaping rebirth—in
an eternal game of hide-and-seek.
In February 1977, biologist Jack Corliss, accompanied
by two colleagues in a cramped craft called the Alvin, took a voyage
to the bottom of the sea. Until then nobody had ever seen submarine
hot springs—breaks
in the Earth's crust where hot magma filters up and cold seawater filters
down. Nor had they seen life in the vicinity. Nonetheless, ninety minutes
after plumbing the depths of the ocean blackness, Corliss and company
came upon the submarine hot springs, or hydrothermal vents. Corliss witnessed
a veil of water shimmer like heat across a beach on a summer day. Although
a mile and a half below the surface, in what should have been the extreme
cold, Alvin's mechanical arm measured the Pacific Ocean to be a tepid
44°C, the temperature of a lukewarm bath. Normally, seawater near
the bottom of the ocean is near 0°C. The shimmering signified a sheet
of rising hot water. Above the undersea volcanic mountain range two hundred
miles west of Ecuador, the Galápagos Rift, Corliss and colleagues
had found an ecosystem mysteriously thriving in the dark. It supported
blind fish, sulfide-oxidizing bacteria, and foot-long clams. Since then
many such ecosystems in the neighborhood of vents have been found; some
are as lush as Atlantis, although without the humans: real-life "octopus's
garden[s] in the shade" replete with iron- and sulfur-using bacteria
and bright red giant tube worms waving like metamorphosing strands of
Medusa's buried head. Blind white crabs scuttle over so-called lava pillows—lava
solidified by contact with water into the shape, roughly, of pillows.
(See James Cameron’s new 3-D Imax film Aliens of the Deep to get
a taste of this experience.) Corliss and company's ecosystem, it turned
out, was indeed a dark one: except for detritus filtering down from the
ocean surface above, it was supported by metabolic reactions occurring
in the dark. Sulfide gases bubbling up with magma from Earth's interior
from the vents and chimneys, so-called black smokers, and reacting with
oxygen in the seawater, "fed" the chemotrophic bacteria at
the base of the ecosystem. Some of the organisms, such as the blind crabs,
may well have evolved closer to the surface. Yet some of the organisms
seemed so adapted to these hot dark spots along the ocean's floor that
it seemed likely none of their ancestors had ever even seen the sun.
The pogonophorans, for example, the giant red tube worms, were red because
of hemoglobin that, at a molecular level, was altered to hold sulfur
atoms. The organisms living on the sulfide-oxygen gradient, rather than
getting energy from light or food, took it from an ancient chemical gradient,
inspiring Corliss to imagine that life itself may have begun in such
a setting. The night after his dive in the Alvin, Corliss retreated to
his room and started notes for a paper on the origin of life in deep-sea
vents.
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