>> 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."Dean Falk, Comments, Current Anthropology, 30:2, April, 1989,
p.141-142.
Robert van de Water wrote,
>>1) Falk says "statistically associated with handedness in humans."
This is jargon for, "most times its associated with handedness, but sometimes
not". If these functions are so variable that we cannot even say for certain
that modern humans will have them in the same place, how can we even begin to
speculate about species that are known only from bone scraps hundreds of
thousands of years old?<<
Mankind is the only being who is handed. This is another piece of data for
the Human > other thread. Schick and Toth state,
"In modern human populations approximately 90 percent of people are
dominantly right-handed (dextral) and about 10 percent are dominantly left-
handed (sinistral). This is a very unusual pattern, and it is unique to
humans. In the rest of the animal world, including nonhuman primates, the
breakdown of handedness (or pawedness) tends to be about 50 percent
left-handed and 50 percent right-handed."~Kathy D. Schick and Nicholas Toth,
Making Silent Stones Speak, (New York: Simon and Schuster, 1993), p.140
Now, your criticism that handedness is statistical has nothing to do with
Broca's area. Broca's area is not the petalia that Falk is talking about.
Falk is not saying that Broca's area is statistical and we don't know where
it is in any given individual. You are stretching here, hoping to find
something we DON'T know in order to support your position.
Robert wrote:
>>Sarcasm aside, I think the argument from size is extremely weak. What do
elephants do with their brains? They are four times the size of human brains
and I don't think all of it can be attributed to learning how to
trumpet. In fact, the brain size of modern human beings vary by almost a
factor of two!!! <
You forget that there is an encephalization quotient. The larger the body
the larger the brain needed to control that body. Elephants are quite large
but not as encephalized as us.
Robert writes:
>>Brain functions are so complex we have only
the dimmest notion of what various parts of the brain are used for and that
from brains that are traumatically impaired. <<
Why is it that we Christians so often want us not to know things in order to
support our positions?
Robert writes:
>>From what Deacon is saying, I gather that Broca's area is used primarily
for advanced language functions in modern humans. <<
Well if Broca's area is used for advanced language functions then maybe the
homo habilis who also possesses a Broca's area, used advanced language
functions. Your admission here seems to undercut your own argument.