Hunter and Biosonar — Again

The Discovery Institute featured a post by Cornelius Hunter on how echolocation (biosonar) is a problem for evolution. This has long been a fixation of Hunter’s. Many years ago, Hunter and I had an exchange about the topic.

Hunter complains about a response from Dennis Venema to the notion that biosonar can’t be the result of evolutionary processes. Venema notes, correctly, that the hearing capabilities needed for biosonar are inherent in mammalian hearing. I pointed that out to Hunter years ago, and he seems not to have learned from that exchange. I noted research on the topic, a study by Fish et al. 1976. I didn’t give the full bibliographic entry for it then, so I’m happy to supplement my earlier takedown of Hunter with that.

Fish, J.F., C.S. Johnson, and D.K. Ljungblad. 1976. Sonar target discrimination by instrumented human divers. The Journal of the Acoustical Society of America 59(3):602-6.

Abstract: A series of sonar discrimination experiments has been performed using instrumented human divers wearing a helmet with a sending and two receiving transducers. Porpoiselike broad band clicks, with energy centered about 60 kHz, were projected and the returning echoes stretched electronically in time by a factor of 128 to enable the divers to hear them. Data were collected using metallic plate targets and targets of different geometrical shapes that were previously used in experiments with a porpoise. A comparison of scores indicated that the instrumented divers performed as well as, and in some cases better than, the porpoise.

C. Scott Johnson, the middle author on the paper, was a physicist and inventor who worked with the US Navy Marine Mammal Program. He was also the sole author on a 1967 audiogram of the bottlenose dolphin, work of such precision and elegance that it remains *the* audiogram cited these several decades later.

It is clear that human hearing, with a fairly generic mammalian capability, is fully functional for the reception and interpretation of biosonar signals, having measurably performed as well in specific tasks as dolphins did.

Hunter also concentrates on dolphin and bat biosonar, and fails to take notice of the other known instances of biosonar, some with fairly rudimentary capability, that are seen in other groups.

Hunter:

I have followed the echolocation research for years. I write about it, and often include it in presentations. I discuss the various ways the echolocation evidence contradicts evolution. So why would there be a section on this subject in this book promoting evolution? Have I missed something? Is there some fundamental aspect of echolocation I have missed? Is there a new paper I have missed, overturning the large body of research?

Has Hunter missed something? Rather a lot, it appears. And even rather a lot of what has been previously brought to Hunter’s attention.

The “I’m an expert” braggadocio Hunter brings here just looks pathetic to me. Of course, I only *did* biosonar research for years.