🚀 go-pugleaf

john baez wrote:

> So what I'm wondering is this: given the complete genome of an organism, how
> much *additional information* would you need to give someone for them to
> be able to build a living copy of that organism?


This is a very interesting thread.
Could your question be similar to say:
Are all clones' phenotypes the same?

I *guess* that the short answer is no.

> Anyway, in my ignorance I imagine it's possible in
> principle.)  Perhaps we could even create a zebra with the aid of a
> one-cell embryo of a horse and a mother horse.  But here we are relying
> on a lot of pre-existing infrastructure... or in abstract terms, a lot
> of pre-existing *information* about how to turn a particular genetic
> code into a living organism of that type.


I think that this is a matter of degree of how chemically compatible
would the donor with the receptor...

> In other words: if we wanted to transmit instructions by radio to a
> highly intelligent alien civilization, which would enable them to create
> a human being, how many bits would the message have to be?   (Assume we
> have already set up lines of communication and can understand each
> other... actually this point is a bit subtle.)  The human genome has about
> 3 billion base pairs, each of which contains 2 bits before we apply
> any data compression, so transmitting the genome takes only 6 gigabytes.
> If we omitted the "junk DNA" (but see below!) we'd only need 600 megabytes.

You will probably still need the junk dna. Some scientists claim that this
gives stability to the coding dna and reduces the probability of transmission
of errors (don't ask me why, I heard it in a conference where they discussing 
the 1/f fluctuations in dna, BTW if anyone can elaborate on this, please do!)

> But the information in the genome is not enough for the aliens to
> build a person!  I think it's possible *in principle* to figure out the
> needed extra information someday and transmit it.  But I have little idea
> how much more information it is.


Do you mean, information like what? The earth magnetic field strength or
the intensity and frequency of light per hour?, or temperature? or the
"recipies" for molecules like water, etc? Where do we stop?
Yes, I agree, only with the dna code you don't go very far, but suppose that
the conditions to re-create a dino in Jurassic Park could well be similar to
the ones necessary to keep related and actual species embryos alive...
 
> For example, say we tried to transmit intructions on how to create a
> one-cell embryo, together with instructions on how this one-cell embryo
> was supposed to be dealt with in order to get a baby organism.  Then
> we'd have to give a lot of information about what the cell is like,
> enough to be able to build a cell *from scratch*.  For all I know the
> amount of information required for this is vastly more than the
> information in the nuclear DNA.  After all, the nuclear DNA never builds
> a new cell from scratch; only with the help of an existing cell.

This extreme situation would require (please let me know if I am getting
it wrong) the complete description of the environment where this is supposed
to occur. Quite a lot of information!

Cheers,

Gabriel