Re: the two questions

"David Cressey" <cressey73_at_verizon.net> wrote in message news:N%g3j.14783$7T.12067_at_trndny09...
>
> "David Cressey" <cressey73_at_verizon.net> wrote in message
> news:xCe3j.27165$701.4743_at_trndny08...
>>
>> "Brian Selzer" <brian_at_selzer-software.com> wrote in message
>> news:tKd3j.66011$RX.14169_at_newssvr11.news.prodigy.net...
>> >
>> > "JOG" <jog_at_cs.nott.ac.uk> wrote in message
>> >
> news:0c832d02-88f5-495c-ab2b-8098afcd8818_at_d21g2000prf.googlegroups.com...
>> > > On Nov 27, 3:49 pm, "Brian Selzer" <br..._at_selzer-software.com> wrote:
>> > >> "JOG" <j..._at_cs.nott.ac.uk> wrote in message
>> > >> Each individual that existed, exists, or can exist has a property
> that
>> > >> distinguishes it from all other individuals that existed, exist or
> can
>> > >> exist; so, yes, there is a property that the caterpillar and
> butterfly
>> > >> share.
>> > >
>> > > Great, we have agreement :)
>> > >
>> > >> The problem is: I don't think haecceity can be observed directly.
>> > >
>> > > This time I agree with you (although I did have to look up what
>> > > 'haeccity' meant) - it is often the case that the identifier we need
>> > > isn't available to us (I mean we can't often check a butterflies dna
>> > > right...).
>> > >
>> > > But we have to find a solution to this in the real world right - If I
>> > > have a butterfly, how do I know it came from the caterpillar from
>> > > earlier? Would you agree there are two options?
>> > >
>> > > 1) Check an identifier that we can manage to observe (dna if we're
>> > > lucky, more likely the jar number we've kept it in, etc.)
>> > > 2) If we couldn't access that identifier (or it was just too much of
>> > > a
>> > > pain to do so), we'd have needed to invent a new identifier as a
>> > > replacement, that was trackable (a representative identifer for the
>> > > insect's 'haeccity' - similar to what biologists do when they 'tag'
>> > > birds).
>> > >
>> > > Again, all in the real world, before we get to a database.
>> > >
>> >
>> > There is a third option: continuous observation. If you never take
>> > eyes
>> (or
>> > the camera) off of the individual, there is no need to reidentify it,
> and
>> > therefore no need for a constant identifier.
>> >
>> > >> If one were able to examine the history of the butterfly, one should
> be
>> > >> able
>> > >> to determine that it coincides with the history of the
> caterpillar--up
>> to
>> > >> the point of the initial snapshot. The problem is: I don't think
>> history
>> > >> can appear in a snapshot.
>> > >
>> > > I get your gist here but hope we can come back to it after you've
>> > > looked at the above question. Regards, J.
>> > >
>> >
>> >
>>
>> Can you tell identical twins apart by examining their DNA?
>> Does twinning occur among butterflies?
>>
>>
>
> So DNA is not good for identity, right?
>
I would have to agree. DNA tells us "what" not "which."
>
Received on Wed Nov 28 2007 - 22:11:54 CET