>Intelligence has survival value, but if the two are unrelated why would
>random mutation and natural selection bother to make anything sentient?
^^^^^^^^^^^
>It seems to me it would be like a fifth wheel, and yet I know for a fact that
>evolution did bother to make at least one thing conscious.
^^^^^^^^^^^^^^^^^^^^^^
The rhetorical teleology with which John poses his taunt might be a clue to
the answer. (Or might not.) Evolution, as he knows perfectly well, isn't
the kind of process that can `bother' about anything. Gravity doesn't
bother to make things fall down and so when things pile up at the foot of
the mountain it's not because of any advance scheme.
I assume that `sentience' means `consciousness' in this context, although,
as has been noted before, it really just denotes any ability to register
sensations, which snails have despite their gross stupidity and Zen
egoless-ness. So it could be that reflexive self-awareness is an
incidental computational by-product of very complex brained bodies
responding in complex ways (understanding, assessing, planning etc) to a
complex environment - rather as the red colour of blood is an accidental
by-product of what it's made out of, and without any teleological merits.
(On the other hand, our perhaps hard-wired fearful reaction to the sight of
blood gushing is surely a selected or easily instilled tropism that depends
on the quantum physics of hemoglobin.)
John's answer to this suggestion, I guess, would be that natural genomic
variations might by now have allowed the emergence of a sub-class of
non-conscious humans (zombies) if sentience in this sense is just an
unimportant side-consequence. Probably so. Hence, it seems plausible that
to be something of which we can say `there is something it is like to be
that' - sorry for the contorted philosopherese - is *not* a meaningless
happenstance, but resulted from benefits that consciousness provided to the
animals with it (in varying degrees). In a way what I just wrote is
compatible with John's comment about evolution bothering to make humans
conscious, but my skin itches horribly when I see informed comments cast in
this dangerously misleading shape.
Damien Broderick