On 27/09/2014 22:55, Matt Mahoney via AGI wrote:
On Sat, Sep 27, 2014 at 2:39 PM, Tim Tyler via AGI <[email protected]> wrote:
Of course in real-world evolution, there are other ways of
getting useful information into the genome. You can choose
sexual partners from a pool of prospective mates. Or you can
kill 99% of the population and breed from the remaining 1%.
Or, you can insert information directly into the genome,
using genetic engineering.
Good point. Considering epigenetic transfer, writing the software
equivalent to our DNA would be more expensive. However, this
additional knowledge cannot contribute to reproductive fitness. The
actual limit is log n bits per generation, where n is the number of
offspring in a steady state population.
I'm not 100% clear on what you are claiming. However it
sounds as though you are still thinking that adaptive information
transfer across the generations is limited in some way by
evolution's "reward" signal. I don't think that is true.
Organisms receive lots of other information in their lifetimes,
and in principle could choose to pass this on to their
descendants - if they thought this was likely to be beneficial.
We can imagine an organism being presented with lots of
information that it knows that its offspring is likely to be
tested on. Can it pass that information on to its offspring -
by using genetic engineering to wire it into their genomes?
Absolutely. Such knowledge can contribute to offspring
reproductive fitness.
There's no known speed limit on evolution.
Yes there is. Copying one bit of information in any form including DNA
requires at least kT ln 2 energy, or about 3 x 10^-21 J at room
temperature.
That's the cost of *deleting* a bit of information (from Landauer's principle).
Copying
is a reversible operation that doesn't require deleting anything. This has been
proven -
for example by building reversible self-reproducing cellular automata.
**
The speed of evolution is limited by the 3.8 x 10^26 W of
energy from the sun, of which only 10^-9 reaches the
Earth, and only 1% of that is converted to chemical energy by
photosynthesis.
That's a proposed limit for evolution on the earth driven only by sunlight.
However there are other plants, other stars and other fuel sources besides
sunlight. This proposed "limit" doesn't seem very limiting to me.
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|im |yler http://timtyler.org/ [email protected] Remove lock to reply.
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