Evolution: a different view (Introduction)

by dhw, Saturday, May 09, 2015, 11:30 (3486 days ago) @ David Turell

Dhw: If McCrone has convinced you that these changes hung around for (hundreds of) thousands of years doing nothing, surely you can summarize his evidence. -DAVID: McCrone uses the same evidence as other scholars: I present a group of articles defending the descended larynx.-I am not attacking the descended larynx. I am attacking your statement that “exaptations appear thousands to hundred of thousand years before any use is found for them. That is a key issue in the idea of pre-planning.” You have used the descended larynx as an example, and I have asked how you or anyone else can possibly know that the descended larynx was not used for (hundreds of) thousands of years. You referred me to a very long article, which I have now read, and there is not the slightest indication that the descended larynx or any other exaptation was not used for (hundreds of) thousands of years. You say that the “changes started over 1.5 million years ago and the accepted start for our style of speaking is 50,000 years ago.” How does that prove that the changes were not used for (hundreds of) thousands of years, and are therefore a key issue in the idea of pre-planning? How do you know that there was not a gradual increase in the range of sounds made by the relevant organisms, as is clearly suggested by the website you drew my attention to in your reply to Tony: 
 
QUOTE: Chimpanzee vocal tracts "could produce a range of at least 10 different phonemes, which appears to be the lower range of human phoneme inventories." This suggests that there was no pre-adaption of the vocal tract necessary to start the lineage speaking. For example, it is not necessary for the larynx to descend before speech sounds become possible. An ape with the motivation to speak could produce enough sounds to make a variety of single-word utterances. De Boer concludes, "Evidence of absence of a lowered larynx is therefore no evidence for the absence of speech in an ancestral hominin." So if we found a Homo erectus fossil in superb enough shape to determine the position of its larynx we could not use an undescended larynx to argue that erectus did not speak. 
Does that point mean that we evolved our vocal tract's present anatomy for some reason other than for proper speech? De Boer thinks not. He has made a series of calculations concerning the relation between vocal tract and position of the larynx and concludes that "there is indeed a larynx depth that results in the largest possible acoustic area covered" which happens to match human female anatomy. There was "a path of ever increasing fitness from a chimpanzee-like anatomy to the human (female) anatomy."
This fitness path suggests that there has been a specific evolutionary trend toward maximizing the range of possible signals.” (my bold)-Absolutely no hint of a change that lay unused for (hundreds of) thousands of years. And forgive me, but I don't see how the writer's suggestion that the change was a pre-adaptation, and his asking what led to its formation, can constitute evidence of non-use or of divine pre-planning.