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发帖数: 657 | 1 This Physicist Has A Groundbreaking Idea About Why Life Exists
Read more: http://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/#ixzz3M5gC9S4N
Jeremy England, a 31-year-old physicist at MIT, thinks he has found the
underlying physics driving the origin and evolution of life
Popular hypotheses credit a primordial soup, a bolt of lightning, and a
colossal stroke of luck.
But if a provocative new theory is correct, luck may have little to do with
it. Instead, according to the physicist proposing the idea, the origin and
subsequent evolution of life follow from the fundamental laws of nature and
“should be as unsurprising as rocks rolling downhill.”
From the standpoint of physics, there is one essential difference between
living things and inanimate clumps of carbon atoms: The former tend to be
much better at capturing energy from their environment and dissipating that
energy as heat.
Jeremy England, a 31-year-old assistant professor at the Massachusetts
Institute of Technology, has derived a mathematical formula that he believes
explains this capacity. The formula, based on established physics,
indicates that when a group of atoms is driven by an external source of
energy (like the sun or chemical fuel) and surrounded by a heat bath (like
the ocean or atmosphere), it will often gradually restructure itself in
order to dissipate increasingly more energy. This could mean that under
certain conditions, matter inexorably acquires the key physical attribute
associated with life.
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Having an overarching principle of life and evolution would give researchers
a broader perspective on the emergence of structure and function in living
things, many of the researchers said. “Natural selection doesn’t explain
certain characteristics,” said Ard Louis, a biophysicist at Oxford
University, in an email. These characteristics include a heritable change to
gene expression called methylation, increases in complexity in the absence
of natural selection, and certain molecular changes Louis has recently
studied.
If England’s approach stands up to more testing, it could further liberate
biologists from seeking a Darwinian explanation for every adaptation and
allow them to think more generally in terms of dissipation-driven
organization. They might find, for example, that “the reason that an
organism shows characteristic X rather than Y may not be because X is more
fit than Y, but because physical constraints make it easier for X to evolve
than for Y to evolve,” Louis said.
“People often get stuck in thinking about individual problems,” Prentiss
said. Whether or not England’s ideas turn out to be exactly right, she
said, “thinking more broadly is where many scientific breakthroughs are
made.”
Read more: http://www.quantamagazine.org/20140122-a-new-physics-theory-of-life/#ixzz3M5gyPQcy
DEC. 8, 2014, 4:48 PM | c*******u
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