Tuesday, May 04, 2021
Interesting experiment, uninteresting result
An article in New Superstitionist describes an interesting experiment with an uninteresting result....
Bats are born knowing the speed of sound. This may not be shocking, as they rely on echolocation to find food and avoid crashing into trees in the dark. But unlike birds that learn their songs, or lions that learn to hunt, bats seem to be born knowing how to echolocate.The comparison doesn't work well, and the experiment shows why, but the author doesn't understand why.
To see whether bats can adjust their echolocation to accommodate changes in the speed of sound, Eran Amichai and Yossi Yovel at Tel Aviv University in Israel trained eight adult Kuhl’s pipistrelle bats (Pipistrellus kuhlii) to fly to a perch within a chamber pumped full of oxygen and helium. Because helium is less dense than other atmospheric gases, sound travels faster through it. The helium interfered with the bats’ echolocation timing and caused them to aim short of the perch. At first, this was expected, but the adult bats never learned to adjust.The basic distinction is clear, whether you explain it by evolution or design. In Nature the speed of sound is constant, so there's no reason to evolve or design a mechanism that adapts to the speed of sound. Hearing CAN be rigid at this level, so it is. Other behaviors depend on the situation right here and now. Hunting is different when the main prey is deer or squirrels. The speed of prey is variable.
Labels: Constants and Variables
¶ 11:14 PM
