In a message dated 8/6/02 5:41:25 AM, [log in to unmask] writes:

>LIGHTS OUT book:  sometimes I think their basic premises are
>a bit shaky.  They say we should be going to sleep at
>sundown, and only the advent of fire is what has made us
>change this.  I find this a bit difficult to swallow whole.
>While some things may have been more challenging after dark
>without a light, it is hard for me to agree that this made
>these things totally "undoable."
>--

Wiley and Formby in Lights Out aren't saying that doing things at night was
impossible -- just that the hormonal shifts that take place with the fading
light and the shift in the quality of light to red (melatonin) would make
doing things at night unlikely -- they describe a probable scene for our
paleo ancestors -- I'll quote: (the scene is after dinner) "Let's assume you
get a bite. Insulin would raise to deal with the incoming carbohydrates you
had dried last summer to eat later and cortisol would start to fall because
you've been fed. That's why we all go for sugar when we're stressed. Remember
we're imagining the mythical natural world here, not ours. In our world,
cortisol never falls until we're completely, unconsciously asleep -- and even
then, because of light leaks, not completely.
    As the sun sneaks off, you and your significant other might try to
prolong the day and warmth by huddling around a small fire entertaining each
together. ... Sex could be an option, depending on the season, the climate
and how charming you are.
    You'd have to expend too much energy to collect enough wood to waste very
much of it on late-day procrastination around a campfire. So your evening
reveries won't last very long. As the pink light of sunset comes over the
landscape, you start to get really sleepy, because while the reflected
"green" bright light of day shuts off melatonin production (at the preoptic
site connection to the pineal gland in your brain), the "rose" light of the
setting sun blocks the green spectrum, causing a release of melatonin to ease
you in to the night's altered state. Having evolved with, not in "response"
to, the changes in light and dark cycles and weather and food supply, it
makes perfect sense that the reflected green and blue light of day and the
rose yellow orange of sunset elicit hormonal and neurotransmitter responses
we can identify as common behavior... So going to sleep with the sunset means
a whole body melatonin bath, and a sharp increase in prolactin... The most
major effect of prolactin in all species is to enhance production of T cells
and NCH cells. These are the first lines of cancer defense..."
    The fact that most of us need an alarm clock to wake up is an indication
that we haven't had enough sleep to do all the hormonal work we supposed to
-- morning light should shut down melatonin and wake us up. Most of us wake
up with a melatonin hangover and prolactin still present. No wonder we need
coffee to stimulate cortisol and get our motors running again. We don't need
to go back to paleo times to know we need more sleep -- just a hundred years
ago people were averaging 9 plus hours a night, even college students.  But
as Wiley says: the light is more seductive than any snake with a carbohydrate.

Been reading more about early man's hunting -- perhaps will give details
another time --but it seems clear that there would have been no need to hunt
at night -- early modern man in fact seems to have developed very successful
hunting strategies including driving herd animals over cliffs or cornering
them in ravines. Found ways of keeping meat for winter too. Very ingenious.

Namaste, Liz
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