A vida antes da Terra ainda continua um grande Mysterium tremendum!!!
terça-feira, abril 16, 2013
Life Before Earth
Alexei A. Sharov, Richard Gordon
(Submitted on 28 Mar 2013)
An extrapolation of the
genetic complexity of organisms to earlier times suggests that life
began before the Earth was formed. Life may have started from systems
with single heritable elements that are functionally equivalent to a
nucleotide. The genetic complexity, roughly measured by the number of
non-redundant functional nucleotides, is expected to have grown
exponentially due to several positive feedback factors: gene
cooperation, duplication of genes with their subsequent specialization,
and emergence of novel functional niches associated with existing genes.
Linear regression of genetic complexity on a log scale extrapolated
back to just one base pair suggests the time of the origin of life 9.7
billion years ago.
This cosmic time scale for the evolution of life has
important consequences: life took ca. 5 billion years to reach the
complexity of bacteria; the environments in which life originated and
evolved to the prokaryote stage may have been quite different from those
envisaged on Earth; there was no intelligent life in our universe prior
to the origin of Earth, thus Earth could not have been deliberately
seeded with life by intelligent aliens; Earth was seeded by panspermia;
experimental replication of the origin of life from scratch may have to
emulate many cumulative rare events; and the Drake equation for
guesstimating the number of civilizations in the universe is likely
wrong, as intelligent life has just begun appearing in our universe.
Evolution of advanced organisms has accelerated via development of
additional information-processing systems: epigenetic memory, primitive
mind, multicellular brain, language, books, computers, and Internet. As a
result the doubling time of complexity has reached ca. 20 years.
Finally, we discuss the issue of the predicted technological singularity
and give a biosemiotics perspective on the increase of complexity.
Comments: 26 pages, 3 figures
Subjects: General Physics (physics.gen-ph)
Cite as: arXiv:1304.3381 [physics.gen-ph]
(or arXiv:1304.3381v1 [physics.gen-ph] for this version)
Submission history
From: Alexei Sharov [view email]
[v1] Thu, 28 Mar 2013 17:00:11 GMT (287kb)
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