Basic HTML Version
ately stresses the "remarkable extent
of fissuration ( convolutions) of the
cetacean cortex." He cocrects older
reports which described an extremely
thin cetacean cerebral cortex.
Debunking this theory, Kruger
shows that the crucial top laycr of the
cerebral cortex - the molecular !ayer
- is extraordinarily thick in cetaceans
( 350-500 microos), more than double
that of comparable animals and in the
same range as man.2
It is dassically thought that the
primarly criterion of intelligence is
the amount and ratio of intrinsic cere–
bral cortex. Therefore, sorne scientists
expected cetacean brains to have a
.rma/J ratio
of intrinsic cortex - and
this would have explained man's
enormous psychological dominance.
Sorry. Kruger proves that the dolphin's
ratio parallels that of the higher
primates.
Now since the
.rtze
of cetacean
dtmity
(number o( oerve cclls in n spccilic
volume)
decreaJtJ
in /'roportion. At the same
time, both the sizc o thc individua l neurons
nnd thc lenj!th and number of their dendritcs
inrrtttlt
in proportion . These focts more thnn
cnmpcnsate for the dedining neuronol density
o(
cetace•ns. since both larger neurons and more
•bund•nt dendrites generate a larger electrically
receptive area. This enables
urh
neuron to
receave and integrate information from many
more neurons. and
co~uently
#tftater mental
potential is 11:ained from
tvu¡ ont n(
the
billions
o(
neurons.
Tower
found that every characteristic of the
hu~e
whale broin followed these •ame rules:
( 1) l t< cerebro-cortical size was
bi~~ger
than
mnn's. (2) lts neuronal density was lc<s (7 ,000
pcr ce. of cortex). (3)
lts
individual neurons
wcre lnr¡tcr in nrea than man's. (4) lts neurons
hnd lon¡¡er dendrites and more of them - the
mnin ("apical") dendrite being of extra·
ordinnry len¡tth!
Consequently. on the basis of eNebro-cortical
micro:tnatomy, whale "roust
be"
mentally !upe·
rior to man to the same degree that man is
mentally superior to chimp!
Let's
be
sure we underst•nd tbis fundamental
conclu,ion. The following chaucteristics are all
usociated with incre>SÍOII mental capacity from
mouse to ut to rabbit to dog to monkey to
chimp to human: increasing brain
wei~~:ht,
in·
crea"OI( ratio of brain wei¡:bt to brain·stem
wei¡¡ht, increa<ing volume of
cerebt3l
cortex,
decre.sing density of cerobro·cortico l neuroM.
increasing size of these neurons and increasin¡¡
len¡tth of cerebro-cortical dendritc<.
fl rrt
iJ
the
point:
All si>e properties continue
to progress unabated from man to whale in
much the same proportions
as
they had pro·
jlre-;sed f rom chimp to man. As a rcsult, whale
"must
be''
more intellie:ent th an man te) the
s-me deO(ree that man is more intelli¡¡ent thon
chimp! Unless....
2 The molecular layer
consastan11: lar¡:ely of
dendrites - is a
key
to
intelli~~:ence.
lt
not
only enables massive intercommunications
be·
tween nrurons but also geneutes extra -cellular
electrical lields (EEG waves] which may
be
in·
timately involved in the mechanisms
of
thou¡:ht.
Still another reason why cetnceans
should bt
man's mental equals if no non· physical com·
ponent exists in man's mind.
24