Re: the two questions

"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?
>

The DNA of identical twins is identical. I haven't a clue whether it occurs among butterflies.

>
Received on Wed Nov 28 2007 - 15:28:14 CET