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where are the pictures?
This section contains speculative material on hairlessness and skin pigmentation, for which the fossilized remains provide no direct evidence one way or the other. The article should make a cleaner distinction between the consensus inferences and speculative possibilities, ,for instance by creating a subsection on hairlessness and skin pigmentation, or by removing this material. —Preceding unsigned comment added by Liontooth (talk • contribs) 21:29, 4 July 2009 (UTC)
Adolescence & Maturity
The sentence "This suggests that early childhood development was more rapid that equivalent to modern adolescents" in this section is grammatically incorrect. What is trying to be said there? Slicing 23:55, 1 December 2005 (UTC)
"Richard Leakey also mentions in his novel Origin of humankind (1995) that Turkana Boy's theoretic vertebrae is narrower than in modern Homo sapiens's, meaning that he could not make complex speech due to less air being received into his lungs"
I pretty sure this is in reference to thoracic vertebrae, as you can see the long, sloping spinous process clearly. As well, the fact that the thoracic vertebrae form the support network to enclose the lungs. The wording of this phrase does not lead me to believe this is speculation on somthing which isn't there. Furthermore, I have only seen the term "theoretic vertebrae" in overly pompous descriptions of abstractions, such as, "the theoretic vertebrae of Hegel's dialectics can weather the weight of analysis." 220.127.116.11 20:38, 16 April 2006 (UTC)devans
Speech, lungs, and vertebrae
"Richard Leakey also mentions in his novel Origin of humankind (1995) that Turkana Boy's thoracic vertebrae is narrower than in modern Homo sapiens's, meaning that he could not make complex speech due to less air being received into his lungs."
Is this correct? I would have thought that body size and air received into the lung have a tight correlation.
Isn't the size of the vertebrae related to nerve control over the lungs, and that is a requirement to control complex speech?
Is there a relationship between the size of the nerves going to the lungs, and the level or complexity of 'speech' production in other animals? —The preceding unsigned comment was added by 18.104.22.168 (talk • contribs) .
- I'm sure body size and lung capacity are related, but only in so much that vertebral size contributes to body size. I would expect the correlation of vertebral size and lung capacity to be much stronger than body size and lung capacity. (A large gut contributes to body size, but does not significantly contribute to lung capacity.) As for nerves, I'm not sure. I can surmise that control of air release would be needed for long composition in a single breath, but I know plenty of people who talk way longer than a single breath. *grins* - UtherSRG (talk) 14:41, 27 May 2006 (UTC)
This statement is in error and should be removed or rewritten. First of all, Richard Leakey's book Origins of Humankind is not a novel. To me the word "novel" implies a work of fiction. Leakey's book is an (admittedly somewhat partisan) account of the state of play in palaeontology in the mid 1990s. (A short review of the book is here - http://www.findarticles.com/p/articles/mi_m1430/is_n8_v17/ai_17596025)
Lung capacity has no real bearing on speech capacity. If this were true then smaller bodied people would be less capable of speech than larger bodied people. This is obviously not the case.
An analysis of the fossil claimed that the channel in the thoracic verterbrae through which the spinal cord passed was significantly narrower in Turkana Boy than in modern humans. This was taken to imply that there was less innervation of the muscles of the diaphragm. The diaphragm is a large muscle in the lower abdomen which expands and contracts the rib cage allowing us to breathe. Modern humans require a high degree of control over the diaphragm in order to coordinate breathing precisely with the muscular movements of the tongue and throat which allow us to speak. We achieve this by having a lot of nerves connecting to the diaphragm, and of course these pass through the spinal cord. If the channel for the spinal cord was smaller in Turkana Boy, this would mean he had fewer nerves reaching the diaphragm and so less control over the diaphragm than modern humans. This in turn led to the conclusion that he would have been less capable of precisely coordinated speech. It's briefly mentioned here - http://www.anthro.ucdavis.edu/faculty/mchenry/AJPA94.pdf
However, another, later, study (which I can't track down right now!) claims that the channel in Turkana Boy's thoracic vertebrae was at the very low end of normal modern human variation, but still just within the normal human range.
Despite this, it's important to remember that precise control of the diaphragm is only one factor in human language - that of speech. Speech is the external productive aspect of language. Control of the diaphragm is involved in the production of most speech sounds - but not all (click sounds don't involve the diaphragm).
Some modern humans, for example people with certain types of cerebal palsy or certain neurological or muscular disorders, have extremely poor control over the organs of speech and breathing, nevertheless they are still perfectly capable of producing comprehensible language. So a small channel in the thoracic vertebrae would merely mean that the speech of Turkana Boy was less precisely coordinated in some respects than the speech of modern humans, it doesn't mean he was incapable of comprehensible speech. Equally the diaphragm has no involvement in gestural or sign language.
- I'm removing some of the speculation about speech abilities based on lung capacity and the opinion that Turkana Boy "seems awkward," which is a typical assumption that preceding species were inferior. It's illogical that he should be an athletic runner but without enough air to speak properly. Furthermore, running ability does not make one a hunter: it also implies ability to flee; just look at pronghorn antelope.
I have edited and added new information. I have removed notification tags, including the chunk below, which I find inappropriate this article and also unsubstantiated:
- However, there are different views on the origin of language:
- 1.9 million years ago (Homo habilis had a large Broca's area able to be seen in the cranium of KNM ER 1813), possible signs of the earliest ability for speech.
- 1.5 million years ago, on the arrival of several distinct more human-like hominins spread throughout Africa, Europe, and Asia (i.e. Homo erectus).
- 600,000 and 150,000 years ago when archaic Homo sapiens dominated regions in the Pleistocene epoch (several members during this period are considered fully modern Homo sapiens)
- 50,000 years ago (fully modern Homo sapiens had already spread through the Old World and slowly into the New World 20,000 BCE. Some believe language coincided solely with modern humans once culture was established by groups such as Cro-Magnon man in Europe. It is still a matter of debate whether Neanderthals had a modern form of language.