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Convergent evolution: Cricket ears turn out to be a lot like vertebrate ears


According to a recent study:

Bushcrickets, also known as katydids, are those green grasshopper-like insects that fascinate children because of their leaf-like camouflage. Using Optical Coherence Tomography (OCT), the European team obtained detailed images of the hearing organs of bushcrickets. The hearing organ on these orthopterans are located on the tibia just below the knee. Called the crista acoustica (CA), this organ, only 0.9 mm long, contains a series of sensory dendrites of decreasing length from the proximal to distal ends of the CA, oriented perpendicular to it. They look like piano strings, and presumably perform a similar function to the hair cells in the Organ of Corti of the mammalian cochlea. The ventral ends of the dendrites in the CA are embedded in the distal wall (DW), analogous to the basilar membrane in the cochlea. The dorsal ends of the dendrites are connected to cap cells which resemble the hair cells in vertebrate cochleae, where acoustic transduction to electric (neural) signals take place.

Other than location (in the heads of vertebrates and on the legs of insects), the functional similarities of the CA to the mammalian cochlea are striking, except that the cochlea is 40 times as long as the insect hearing organ! It’s a remarkable example of convergence already, and there is more to come.

Evolution News, “Hear This: Cricket Ears Evolved Like Vertebrate Ears” at Evolution News and Science Today (December 15, 2021)

The paper is open access.

Here's the revised version: https://polistrasmill.com/2021/12/22/katydids-part-2-revision/ polistra
convergent evolution ...yeah yeah .... Darwinists invented this term, when more and more examples of the same design showed up in evolutionary unrelated species ... Years ago I started a blog regarding this issue (link below) What rational person can buy this Darwinian non-sense of convergent evolution, that blind unguided natural process created very complex design repeatedly (sometimes up to 100 times), sometimes on multiple design layers ... some of the most extreme example is placenta ... a very complex organ, scientists still don't entirely understand how placenta works ... but, according to Darwinists, placenta should have evolved repeatedly up to 100 times independently in various evolutionary unrelated species What is wrong with this people? Here is the blog, i have collected tons of example of 'convergence' https://www.stuffhappens.info martin_r
I did an animation of an earlier study on this subject, and I'm rigging up an expansion to include this newer information. Katydids have one major advantage over mammals, which appears to serve a purpose we don't understand yet. Each front leg has two eardrums facing roughly 90 degrees apart. Thus each leg can do its own localization, and each can be aimed to localize even more. The 90 degree separation implies an ability to distinguish POLARIZED sound mechanically transduced from the ground or a tree limb, which we obviously can't do. http://polistrasmill.blogspot.com/2012/11/see-what-happens-when-you-look.html Crickets can navigate by POLARIZED light, so a parallel system for polarized sound would fit the pattern. http://polistrasmill.blogspot.com/2020/10/another-amazing-navigational-sense.html polistra

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