News: A First-Principles Model of Early Evolution.

11 July 2007 A First-Principles Model of Early Evolution.

http://www.alphagalileo.org/index.cfm?_rss=1&fuseaction=readrelease&releaseid=522002

"*"
In a study publishing in PLoS Computational Biology, Shakhnovich et al
present a new model of early biological evolution ? the first that
directly relates the fitness of a population of evolving model
organisms to the properties of their proteins.

Key to understanding biological evolution is an important, but
elusive, connection, known as the genotype-phenotype relationship,
which translates the survival of entire organisms into microscopic
selection for particular advantageous genes, or protein sequences. The
study of Shakhnovich et al establishes such connections by postulating
that the death rate of an organism is determined by the stability of
the least stable of their proteins.

The simulation of the model proceeds via random mutations, gene
duplication, organism births via replication, and organism deaths.

The authors find that survival of the population is possible only
after a ??Big Bang?? when a very small number of advantageous protein
structures is suddenly discovered and exponential growth of the
population ensues. The subsequent evolution of the Protein Universe
occurs as an expansion of this small set of proteins through a
duplication and divergence process that accompanies discovery of new
proteins. The model resolves one of the key mysteries of molecular
evolution ? the origin of highly uneven distribution of fold family
and gene family sizes in the Protein Universe. It quantitatively
reproduces these distributions pointing out their origin in biased
post ?Big Bang?? evolutionary dynamics of discovery of new proteins.
The number of genes in the evolving organisms depends on the mutation
rate, demonstrating the intricate relationship between macroscopic
properties of organisms ? their genome sizes ? and microscopic
properties ? stabilities ? of their proteins.

The results of the study suggest a plausible comprehensive scenario of
emergence and growth of the Protein Universe in early biological
evolution.
--
Bob.

.

Relevant Pages

  • Re: Color vision
    ... but with advances in molecular biology and genetics. ... sense in terms of evolution. ... sequences is essentially the same in all organisms. ... determined the three-dimensional structures of two proteins that are ...
    (talk.origins)
  • Re: Proteins that control evolution
    ... set of proteins discovered in the electron transport chain that seems ... saying that evolution has always been thought to be 100% ... isn't that the fourth time already this month that biology has ... optimal control strategies in their evolutionary dynamics". ...
    (talk.origins)
  • More Vatican Support for Evolution
    ... ROME -- Charles Darwin's theory that all living organisms have ... and evolution at the State University of New York at Stony Brook. ... For example, using mice, monkeys and other nonhuman species to ... Some of the latest research in evolutionary biology has also shown ...
    (talk.origins)
  • Re: Irreducible complexity is expected
    ... Irreducible complexity is seen, by some, as a problem for evolutionary ... Non-reducible, that means efficient, organisms will result. ... evolution plenty of time to act on organisms). ... Yes, it's taking the world of biology by storm, isn't it? ...
    (talk.origins)
  • Re: News: Evolutions new wrinkle.
    ... Proteins with cruise control provide new perspective ... of proteins found in most living organisms act like adaptive machines, ... possessing the ability to control their own evolution. ...
    (talk.origins)