broca's brain

GRMorton@aol.com
Sat, 30 Sep 1995 20:45:38 -0400

I have raised the issue of the status of fossil man as a means to determine
how recently or how distant the flood must have been as well as to point out
the deficiencies in the presently advocated views of most writers in this
area. I ran into the following quotation in an article on the origin of
language. The data is not new but is still a very interesting data point.

The art objects I have mentioned are indicative of human activity, but are
not the definition of humanity. Hewes below outlines the problem (he uses
'depiction' for art):

"If we restrict 'depiction' to the kinds which survive from the Upper
Paleolithic, many ethnographic groups are without it to this day, although
they possess complex languages and oral traditions replete with 'depiction'
in the literary sense."~Gordon W. Hewes, Comments, Current Anthropology,
30:2, April, 1989, p. 145-146.

One thing which clearly separates mankind from the apes is the posession of
a complex, spoken language. The motor aspects of language is largely
controlled by an area of the brain known as Broca's area. Damage to Broca's
area leaves one unable to speak by destroying motor control of the speech
apparatus
Broca's area leaves a mold on the inside of the cranium and can be
detected in endocranial casts from fossil material. The quote says most of
what is important concerning the status of ancient fossil man.

"But monkeys don't have language and humans do. Are [141/142] there
morphological manifestations of human brains that (a) correlate with
functional lateralizations including language and (b) are capable of leaving
traces in the hominid fossil record? Indeed there are. Shape asymmetries of
the frontal and occipital lobes, known as petalias, exist in human brains
(and to a lesser degree in brains of monkeys and apes) and are statistically
associated with handedness in humans. Further, a characteristic sulcal
pattern associated with Broca's speech area in left frontal lobes is present
in human but not in ape brains. Both humanlike petalis and the pattern of
sulci associated with Broca's area have been detected on endocranial casts
(endocasts) from the early part of the hominid fossil record.
"The oldest evidence for Broca's area to date is from KNM-ER 1470, a H.
habilis specimen from Kenya, dated at approximately two million years ago.
From that date forward, brain size 'took off,' i.e., increased
autocatalytically so that it nearly doubled in the genus Homo, reaching its
maximum in Neanderthals. If hominids weren't using and refining language I
would like to know what they were doing with their autocatalytically
increasing brains (getting ready to draw pictures somehow doesn't seem like
enough)."~Dean Falk,"Comments," Current Anthropology, 30:2, April, 1989, p.
141-142.

This is one more data point in the attribution of human-ness to fossil man.
If there is physical evidence for a language in fossil man, then how can we
exclude him? I know that we can never prove that KNM-ER 1470 spoke nor even
prove that the language was complex, because there were no tape recordings
but the physical evidence is the next best thing. Other than the FACT that
Broca's area exists in KNM-ER 1470 anything else we say about the quality or
lack there of to the language this structure might have produced, is
speculation. And yes there is the possibility that the structure did not
produce a language. But given all these caveats it is fascinating that the
only creature on planet earth today which has this structure, is man.

I will save Stephen Jones some time here. Yes, this will fit within your
two Adam theory.

glenn