Unanswered questions wrapped in a spider web
Imagine if you had to build this every time you got hungry and needed to catch a Big Mac |
Walking through the woods with my demon detector, this
little fella pictured on the right halted my journey.
Ok, you might be thinking, "What the heck is a demon
detector and how do you walk it?"
For now, suffice it to say that my demon detector plays a
central role in my next article, The demon lurking in your
e-cig. You really wouldn't want me
to spoil the upcoming article by explaining what the demon lurking in your
e-cig is and what a demon detector does, now would you? My couple of faithful readers, however, can
probably guess what the heck I'm talking about.
Now, back to the unanswered questions wrapped in a spider
web.
The sunlight shone on this web at the perfect angle to
highlight all its intricacies. You
might think dew accentuated the sun's effect, but the picture was taken a
couple of hours past noon. The dew, if
there were any that morning, had long since dissipated. What you're looking at is a web and the glue
the spider produces to make the web sticky.
The angle of the sun reflected off the web and drops of glue perfectly.
The sight stopped me in my tracks on my journey with my
demon detector. Usually, I trek through
the woods crashing through spider webs woven across the path simply because I
don't see them until I've walked into them.
At certain times of the year, I have gotten into a habit of carrying a
stick that I wave up and down in front of me to clear the path of these unseen
traps that are harmless to you and me, but deadly to other insects.
The intricacy of the web caught my attention first. What engineering degree from what school did the little fella learn how to build this design?
Ok, I haven't had that many beers, yet. Obviously, the little fella didn't go to
school to learn how to build an insect trap so he could eat dinner. He just "knows" how to do it. So first real question - does the web
building abilities of spiders imply knowledge has a genetic basis?
If how to build a web is genetic based, what are the genes encoding this
knowledge and how did creatures evolve to start encoding knowledge in the first
place?
Yeah, I know what you're thinking. "Who cares?
Spiders just know how to do it because it's instinctual."
Of course it's instinctual.
That's the definition of "genetic knowledge", I reckon. Every spider of this species spins the same
geometric pattern. Other species of
spiders spin other designs. The orb
spider spins webs three feet across with strands that are more tightly
wound. The writing spider puts a jagged
scribble in its web. Funnel spiders
build "white tornado" webs. Each
species is genetically wired to build a web almost identical to every other
spider in its species, but the genetic wiring is most definitely different
among the species.
Not impressed? Think
of the engineering that must be genetically encoded to get the almost identical
webs of each species. The little fella
in this picture had to pick a location where he had at least five points to
anchor the web. Those five points had
to be spaced within certain parameters to allow for the shape of the final web
that we see. A mathematician could
probably calculate that range of the five points in relation to each other and
even calculate the number of probable good locations per cubic foot of forest
volume for the little fella to build a web.
A biologist could tell us if the spider only uses five points every time
he builds a web or uses more (or less) depending on location without losing the
design integrity.
Fortunately, the spider doesn't need to concern itself with
bigger questions this web raises like how
does that little body produce so much silk and glue? Why do insects get stuck in the web, but the spider does not?
Ooops, that last question is answered. The narrator is a bit of a goofy nerd type,
probably high on spider venom or something, but he answers why spiders don't get stuck in
their own webs in a quick, fun, and entertaining way.
His answer, however, complicates the idea that knowledge is
genetic. Not only does the spider have
to know the proper location, points of anchor, and the geometric design of its
final product, but it also has to know which strands to make non-sticky, which
ones to make sticky, and where to place the glue. Look at the picture again.
The sun reveals the web isn't smeared in glue all over. There are carefully placed droplets on the
strands and, yes, strands almost bare of glue, particularly at the center where
the spider spends most of its time while it waits for dinner to come to it.
Posted by Five Drunk Rednecks
Comments
Post a Comment