[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: courses



HP Conway observed:
<If character acquisition is assumed to be random (back to this in a
minute), we could say that it is highly improbable that two organisms
will have the same (or very similar) character sequence.>
and
<Now, of course is the real problem. We all know that character
acquisition is not random, which reduces the improbability of matching
character sequences.>

You might want to clarify '...character acquisition is not random.'  If it
is not random, then it has direction, no?
What I had in mind in my comments, aside from their direct import about the
meaning of random, is the idea that if characters arise at random to be
selected for as a kind of weeding out process (or just held as neutral),
then by definition similar species with different ancestries will have some
similar mutations, and that could mislead you about a connection between the
species.  (There are physical constraints to mutation.)
There's also the fact that something you see as a significant character
linking two species together may be in actuality a mutation that showed up
for only a short time, even in a single individual.
The likelihood may be small that chance will produce exactly matching
mutations, but given enough time, any speed of mutation will produce a
match.  The 'improbable', the fluke, happens.  Unless you allow for some
functional significance or other linkage between characters in an
individual...