N.Wells
Posts: 1836
Joined: Oct. 2005
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Gary has claimed here in the past that the giraffe's elongated laryngeal nerve allows a lag that creates resonance that permits production of ultrasound. People here, including me, pointed out that "nerve lags" do not affect sound frequency, that the resonating chamber is the larynx, not the throat and not the lungs, and that elephants and rhinos produce a lot of infrasound without having long necks (also whales, hippos, okapis, rhinos, and alligators). Gary was unable to rebut, but he is now repeating his argument over at Sandwalk, at http://sandwalk.blogspot.com/2015.......nt-form . ["The one about the laryngeal nerve of a giraffe does not consider that a vocal circuit needs a timing delay to achieve resonance of the entire acoustic chamber that starts in the lungs."]
This behavior is outside the bounds of acceptable scientific behavior on Gary's part, further supporting the conclusion that he is not doing science.
We can add to this some recent science that makes Gary's case even worse, from Herbst et al., 2012, Science, How low can you go...., at http://www.sciencemag.org/content....95.full
| Quote | | [from introduction, with references & some text deleted] Mammal vocalizations from different species span a frequency range of nearly five orders of magnitude, from 9 Hz in some whales to above 110,000 Hz in some bats. .... The source of most mammal vocalizations [are at least two mechanisms for] vibrations of the vocal folds, located within the larynx. ..... In the active muscular contraction (AMC) or “purring” mode, .... the highest frequencies producible are limited by muscle contraction speeds, which even with superfast muscles cannot get much higher than 200 Hz. However, this mode allows arbitrarily low fundamental frequencies. In contrast, frequencies in the myoelastic-aerodynamic (MEAD) or “flow-driven” mode are tightly limited by the physical size of the oscillators, because the fundamental frequency range for a species is determined by the size of the vibrating tissue (i.e., the length of the vocal folds or cords). Consequently, there is a direct interspecific relationship between body mass, vocal fold size, and fundamental frequency for MEAD-induced vocalizations, but no such relationship for purring (Fig. 1A). For individual animals intraspecifically, the fundamental frequency range is also influenced by age and the consequent change in the vocal fold dimensions....... the MEAD mechanism is probably more energetically efficient, because it requires no active time-varying neural firing or muscular contraction |
Note that last part: "requires no time-varying neural firing or muscular contraction". Purring (which does require active nerve control) is something that cats do, not giraffes. The "flow-driven" model that elephants and giraffes use rely simply on a large larynx (not throat) with very long vocal folds that run the length of the larynx slapping together at a low rate. One of the experiments that the scientists did incidentally proves that no "nerve lag" was involved in producing infrasound (not that they or anyone other than Gary [and maybe a creationist or two] has ever entertained this hypothesis) by showing that nerves were not involved: they produced the sounds by blowing air through the larynx in a dead animal. (This was from the base of the larynx, not from the lungs or the base of the throat.)
Nerves will be used in fine control of the infrasound, just not in producing it in the first place. The fact that elephants, hippos, alligators, okapis, and rhinos control their infrasound successfully without long throats and without exceptionally long recurrent laryngeal nerves shows that Gary is just spouting whatever rubbish he can make up that sounds to him like it might get him out of the hole he has dug himself into, i.e. anything that sounds good, or which can be distorted to sound like it provides support, or merely confuses the issue in a way that makes his failures seem less awful, completely without regard to accuracy and honesty. It has become clear that this is standard operating procedure for Gary, and in this he follows a well-trod creationist-IDist path.
He also reiterates the falsehoods that atheism is a religion (when it is the absence of religion) and that Muller cells make the backward wiring of the vertebrate eye a good design (as opposed to a modification to a pre-existing element that serves as a kludged or briccolaged fix to a problematic design).
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