[FRIAM] bilateria

[Steve Smith]

I'm not clear on your (EricS's) age (childhood) but I have a full bound 
collection of SciAm which might date back that far I'd love to find 
someone to take over from me... I already tried unloading them on 
Zingale but he ducked that bullet.

Any takers?   Old paper and dust?
>
> > Eric writes
> > When I was a kid, there was some article (maybe Sci. Am.?) that I 
> found wonderful.
>
> Bilateral Symmetry may apply to in magazines too :-) Here's a 1973 
> article in "American Scientist" instead of "Scientific American" :-)
>
> https://www.americanscientist.org/article/how-the-owl-tracks-its-prey
> from the article:
> Asymmetrical placement of the ears (one higher than the other) allows 
> the owl to determine both the azimuth (horizontal direction) and 
> elevation (vertical direction) of sounds.
>
>
> On Mon, Jul 14, 2025 at 2:33 PM Santafe <desmith at santafe.edu> wrote:
>
>     > On Jul 15, 2025, at 2:41, glen <gepropella at gmail.com> wrote:
>     >
>     > Now, I'm sensitive to the argument that all this falls under
>     parallax, even radially symmetric body types and the 9 octopus
>     ganglia. And bi- vision, hearing, etc. is a simple form of
>     parallax: triangulation.
>
>     When I was a kid, there was some article (maybe Sci. Am.?) that I
>     found wonderful.
>
>     It had to do with owl ear asymmetries, which are produced by tufts
>     of stiff feathers at unequal positions in front of whatever
>     feather-hood (or something) channels sound to the ear canals.
>
>     Upshot of the articles was that owls need resolution in the
>     vertical as well as the horizontal, from phase, intensity, and
>     packet-arrival-time differences (including what acousticians term
>     the “head-shaped transfer function”, as I learned some decades
>     later working among the acousticians for a few years).
>
>     Article claimed (I have no way to check without a dive to see what
>     has been done since) that owls and people have about the same
>     acuity in lateral position of a sound’s origin, if the sound has
>     enough shape (so, not a clarinet) to cue from.  But people have
>     terrible vertical acuity. For owls, the vertical acuity is
>     ballpark-comparable to the lateral.
>
>
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