[extropy-chat] Deception theory, lies and natural selection

[spike]

> bounces at lists.extropy.org] On Behalf Of Robert Bradbury
> 
> ...
> 1. Devious Butterflies, Full-Throated Frogs and Other Liars, C. Zimmer, 26
> Dec 2006
> http://www.nytimes.com/2006/12/26/science/26lying.html?pagewanted=print
...
> 
> A croak is how male green frogs tell other frogs how big they are. The
> bigger the male, the deeper the croak. The sound of a big male is enough
> to scare off other males from challenging him for his territory...

and
 
> ... Some small males lower their
> voices to make themselves sound bigger. Their big-bodied croaks intimidate
> frogs that would beat them in a fair fight."


Another interesting question is "How do the smaller frogs manage to sound
larger?"

Consider the strings on a piano.  The lower notes are created by longer
strings.  But a piano or guitar is tuned by varying the tension in the
strings, so that a shorter looser string can match the pitch of a longer
tighter one, to first order.

The "first order" qualifier is added because a musician can tell the
difference, can tell which string made which note.  The reason is that the
harmonics are different between them; the power spectral density of the
higher multiples of the pitch would differ.  So there are inherent
limitations to how short and loose the piano string can be made and still
hit a certain pitch.  Surely the same would be true of the frog's
noise-making organs.

Consider those high-techy Bose speakers that create that booming bass sound
even tho the speakers themselves are very small.  The Bose pseufers fool the
ear by doing a trick with the third and fifth harmonics (I am not sure of
the spelling, it might be psoofers.)  The brain somehow interprets the
signal as half the frequency that is actually being produced.  It's kind of
the opposite of falsetto in a way.  Stereo hipsters, feel free to educate us
on how those super low frequencies are simulated on small speakers.  I know
only a very general arm-waving explanation.

It would be interesting to record the signals of the lying little frogs,
then try to determine by Fourier analysis or Amara's wavelet technology to
see if they are doing something like the harmonic overlaying trick that the
stereo people are doing.  That would be way cool if evolution had discovered
that technique a long time ago.

spike