Information Theory - Part 3: Life
What
other topics does information theory answer, Charles Seife asks and answers in Decoding
the Universe.
How about that question from philosophy: what is the purpose of life?
And the
answer increasingly seems to be:
“Duplicate your
(genetic) information. Sure, the programs go about the task in different ways,
but the goal is always the same. Reproduction. All else is decoration –
decoration that helps the program to achieve its ultimate goal.”
Wonder
if that’s true? Isn’t the individual trying to reproduce the entire organism? How can one say that
information within is trying to reproduce (only) itself?
Are we
stuck with a chicken and egg question here, each left to his own preference
with no way to prove/know?
Aha,
but organisms in nature increasingly align with one view:
“That the organism reproduces is just a by-product of the information duplicating itself…
sometimes.”
This
view explains why an ant colony has only fertile organism – the queen. By the
copy-the-organism view, it makes no sense why the other sterile ants do all the
work! But by the copy-the-information view, you realize that because the queen
is their mother, so all her children share half their DNA with every ant in the
colony. In which case, the sterile ants are ensuring (half) their instructions
(DNA) are getting duplicated.
This
view also explains the t gene in mice. If there’s just one copy of it in an organism,
nothing good or bad happens. Normally a gene has 50% chances of getting passed
on during reproduction. Not so the t gene. It has a 95% chance of being passed
on. Do the maths and you realize that a mice population should soon get overrun
with copies of the t gene. And so it does. But now more and more individuals
end up with 2 copies of the t gene (one from each parent). Where one copy was
harmless, two are lethal. And with more individuals having 2 copies, they start
dropping like flies. Such a gene doesn’t fit the copy-the-organism worldview,
but it certainly fits the each-piece-of-information-only-cares-to-make-copies-of-itself.
Still
not convinced? Take the bacterium-like creature responsible for our
mitochondrial DNA. That creature is long extinct. And yet, the information that
was in that creature now resides in us, in the mitochondria of each of our
cells:
“The information
has jumped vehicles, and when the original organism died out, the information
survived.”
Information
can survive the extinction of the species: Try beating that!
Comments
Post a Comment