A recent mathematical analysis says that
life as we know it is written into the laws of reality. DNA is built
from a set of twenty amino acids - the first ten of those can create
simple prebiotic life, and now it seems that those ten are
thermodynamically destined to occur wherever they can.
For those unfamiliar with thermodynamics, it’s the Big Brother of
all energy equations and science itself. You can apply quantum
mechanics at certain scales, and Newtonian mechanics work at the right
speeds, but if Thermodynamics says something then everyone listens. An
energy analysis by Professors Pudritz and Higgs of McMaster University
shows that the first ten amino acids are likely to form at relatively
low temperatures and pressures, and the calculated odds of formation
match the concentrations of these life-chemicals found in meteorite
samples.
They also match those in simulations of early Earth, and
most critically, those simulations were performed by other people. The
implications are staggering: good news for anyone worried about how
we’re alone, and bad news for anyone who demands some kind of
“Designer” to put life together - it seems that physics can assemble
the organic jigsaw all by itself, thank you very much, and has probably
done so throughout space since the beginning of everything.
The
study indicates that you don’t need a miracle to arrive at the chemical
cocktail for early life, just a decently large asteroid with the right
components. That’s all. The entire universe could be stuffed with
life, from the earliest prebiotic protein-a-likes to fully DNAed
descendants. The path from one to the other is long, but we’ve had
thirteen and a half billion years so far and it’s happened at least
once.
The other ten amino acids aren’t as easy to form, but
they’ll still turn up - and the process of “stepwise evolution” means
that once the simpler systems work, they can grab the rarer “epic
drops” of more sophisticated chemicals as they occur - kind of a World
of Lifecraft except you literally get a life when you play. And once
even the most sophisticated structure is part of a replicating
organism, there’s plenty to go round.
It’s no accident that we see stars in the sky, says famed Oxford biologist Richard Dawkins: they are a vital part of any universe capable of generating us. But, as Dawkins emphasizes, that does not mean that stars exists in order to make us.”It is just that without stars there would be no atoms heavier than lithium in the periodic table,” Dawkins writes in The Ancestors Tale -A Pilgramage to the Dawn of Evolution, “and a chemistry of only three elements is too impoverished to support life. Seeing is the kind of activity that can go on only in the kind of universe where what you see is stars.”
A fascinating corollary according to both Dawkins (see video below) and astrophysicist Neil deGrasse Tyson, is whether DNA is inevitable as
the foundation for the coding of life, or has life started with DNA in only
one place in the solar system and then spread among the livable
habitats through panspermia. Microbial life can land on and seed
another planet, thereby not requiring that you have to create life from
scratch multiple times and in multiple places.
Another totally intriguing possibility, one of many that deGrasse
Tyson Director of the Hayden Planetarium at the American Museum of
Natural History and host PBS’s NOVA scienceNOW., describes in Origins: Fourteen Billion Years of Cosmic Evolution, is that there is life that has encoding that has nothing to do with DNA.
It is the relentless shifting and mutating of DNA, says Dennis Overbye in a brilliant essay in The New York Times,
that generates the raw material for evolution to act on and ensures the
success of life on Earth (and perhaps beyond). Dr.Paul Davies
co-director of the Arizona State University Cosmology Initiative said
that he had been encouraged by the discovery a few years ago “that some
sections of junk DNA seem to be markedly resistant to change, and have
remained identical in humans, rats, mice, chickens and dogs for at
least 300 million years.”
But Dr. Gill Bejerano, Assistant Professor of Developmental Biology and of Computer
Science
at Stanford, one of the discoverers of these "ultraconserved" strings
of the genome, said that many of them had turned out to be playing
important command and control functions.
"Why they need to be so
conserved remains a mystery," Berjerano said, noting that even regular
genes with known functions undergo more change over time. Most junk
bits of DNA that neither help nor annoy an organism mutate even more
rapidly, Overbye points out.
What your quess: Is the DNA the
cosmic code for life in the universe, or is it possible that there’s
are alien, unknown foundations? At the Galaxy, we place our chips on
DNA.
Don’t miss the Dawkins video below…get past the first 5 minutes and you’ll witness a brilliant discussion of his views on DNA as the universal foundation for life in the universe.
Posted by Luke McKinney with Casey Kazan.
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