WOW!
This is the BEST piece of real science in a LONG TIME. Utterly amazing.

The experiments were done by Gottwald at Univ. of Bonn. Basic point: A peculiar elephant-nosed fish unsurprisingly called the elephant-fish uses its 'trunk' as Doppler radar to detect edible insects. Other fish use their electric fields as weapons and FM stereo two-way radio and radar, but the elephant-fish doesn't just detect echoes.

It distinguishes between uninteresting dead rocks and interesting insects by detecting the capacitive absorption and discharge from the object. A solid rock reflects charge without any dynamic alteration. A living thing has complicated capacitance in its various cavities and membranes, and some active response from its neurons. The echo is non-linear in specific ways.

These experimenters simulated rocks and bugs with actual resistors and actual capacitors. The fish ignored the resistors and tried to eat the capacitors!

Astonishing natural function, and even more astonishing insight and understanding by the researchers.

But the researchers picked an inadequate metaphor to explain the action. They used color vision as a metaphor, which doesn't capture the idea of depth perception caused by phase modification.

Let's see if I can get closer with a sound-based explanation.

The capacitive response reshapes the returned voltage field by initially absorbing and then reflecting in a complex way, as the tissues and neurons of the bug discharge or actively respond to the input pulse.

The reshaped echo has a different and dynamically varying spectral pattern, like the upsweeps and downsweeps that a bat detects, or the upsweeps and downsweeps of vowels that humans detect. In this case the sweeps are based on phase instead of frequency, which humans can't detect. So I've tried to simulate with fast sweeps of frequency.



In this animation the elephant-fish (played by old Five Eyes Opabinia) is sending pulses out and using its trunk to detect the echoes. I'm using sound instead of charge because humans can't detect charge intelligently. The live critter in the middle takes the echo and reshapes the spectrum, while the rocks simply return the original echo. I've tried to give you a sense of what the fish might 'hear'.



Well, as usual Firefox's idiot "security" theater prevents me from including the video, so I have to resort to a LESS SECURE method. Here's the short video for download. Just 20 seconds, but it gets the point across. You can hear how a spectrum-shifted response differs from an unchanged echo.


= = = = =

Later dumb thought, inspired by the easy typecasting of Opabinia. Life is purpose. Each gene is a specific purpose or goal, implemented in all sorts of ways. There must be a basic gene for 'prehensile snout', implemented in unique ways by Opabinia, elephant-fish, and elephants. Possibly the familiar mammalian snout is a degenerate version with the grasping function deleted, leaving only the olfactory and electrical sensing functions. There are some semi-degenerate snouts in mammals like aardvarks and coati mundi.

Labels: Carver, Grand Blueprint

  ¶ 12:26 PM