Editorial on Ellison, McNealy, and national ID card

Damien Morton morton@dennisinter.com
Thu, 25 Oct 2001 13:48:44 -0400


So, short of using the entire DNA sequence as a GUID, would you say that
we can probably look forward to competing (and incompatible) standards
of 'compact' GUID representations.

----------------------------------------------------
Damien Morton, Technical Director, Dennis Interactive

The glass is neither half-full nor half-empty. Its too big.

> -----Original Message-----
> From: Clay Shirky [mailto:clay@shirky.com]
> Sent: Thursday, October 25, 2001 1:45 PM
> To: Damien Morton
> Cc: 'Jim Whitehead'; 'Clay Shirky'; fork@xent.com
> Subject: Re: Editorial on Ellison, McNealy, and national ID card
>=20
>=20
> > Any ideas on howbig this DNA GUID might be (in bits)
>=20
> Very good question, don't know the answer.
>=20
> Genotypes are differentiated by analysing genetic sites called Short
> Tandem Repeats, or STRs or microsatellites.  These are places where
> all members of a species have some short DNA sequence repeated in
> tandem. (STR is sometimes pronounced 'stutter', for obvious reasons.)
>=20
> The sites where these STRs occur are the same, as are the sequences
> themselves. What differs is the number of repeats.
>=20
> I seem to remember (though can't easily find now) a reference saying
> that commonality in two samples of something like a dozen STR sites is
> enough to rule out false positives.=20
>=20
> Given that any numerical space that could positively rule out
> namespace collisions in DNA would need to be only order 10**10, I
> suppose this means that the number of repeats thet could exist at any
> given site is only in the hundreds.
>=20
> -clay
>=20