THINKING ABOUT THE BRAIN

by Drs. Don DeYoung and Richard Bliss*

Introduction

Whether considering a star or a starfish, design remains one of the

strongest evidences in support of Creation. Opponents never have known

how to deal with the compelling design and plan observed in all parts

of nature.(1) Meanwhile, science accumulates new examples of design

every day. Scripture adds its approval, declaring that there is no

excuse for missing the implications of creative design (Romans 1:20).

But there is one particular aspect of design which is so powerful, so

convincing, that it almost seems unfair to challenge evolution with

it. The reference is to our brain, the greatest concentration of

chemo-neurological order and complexity in the physical universe. It

is a video camera and library, a computer and communication center,

all in one. And the more the brain is used the better it becomes! A

detailed picture of the human brain is slowly emerging, the origin of

which seems entirely beyond comprehension from a naturalistic point of

view. We see remarkable purpose and interdependence within the

brainÄevery part works for the benefit of the whole. Such features are

not totally understood; the brain is unable fully to understand

itself. As always, we cannot fully understand the created, intricate

details of the present-day world.

Description of the Brain

The adult brain weighs about 1350 grams, just three pounds, yet it

handles the information of 1000 supercomputers. The fundamental unit

within the brain is the neuron, or nerve cell. Each cell, about 10 to

the minus-6th power meter in diameter, contains a nucleus and

branching fibers called dendrites and axons. When a cell "fires," it

sends electro-chemical impulses along its axon extension to

neighboring neurons. These signals, or brain-wave patterns, are in the

range of microvolts. Figure 1 shows two neurons with dendrite-axon

contacts called synapses. Our brain contains about 10 billion neurons

(10 to the 10th power). During the first nine months of life, these

neurons form at the astounding rate of 25,000 per minute.

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Figure 1. Two neurons are shown, representing the ten billion cells

within the brain. Axons are fibers that interconnect the cells. Axons

are long in motor neurons; the dendrites are long in sensory neurons.

The number of branching dendrites is large and variable.

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Each neuron is in dendritic contact with perhaps 10,000 other neurons.

The total number of neurological interconnections is on the order of

10 to the 14th power (100 trillion). This number is equivalent to all

the leaves on all the trees of a vast forest covering half of the U.S.

The total length of the nerve dendrites in an adult brain is over

100,000 miles!(2) At any given moment the many dendrite connections

can be visualized as light switches that are either on (firing) or

off, controlled by a chemical transmitter. Thus the brain holds at

least 10 to the 14th power bits (binary digits) of information.

Actually, it is a much greater number, since the neurons also show

intermediate firing states, somewhat like a light-dimmer switch.

Consequently, the brain shows both digital and analog characteristics.

At any given moment, perhaps 10% of the brain cells are firing, at a

frequency of about 100 hertz. This implies a rate of 10 to the 15th

power signals or computations every second. For comparison, the Cray-2

supercomputer's speed is 10 to the 9th power computations per second,

with a storage capacity of 10 to the 11 power bits. Thus, the storage

capacity of this supercomputer is 1,000 times less than that of the

human brain. Table I shows the memory capacity of several systems.

Note that the potential brain capacity is estimated as at least

equivalent to that of 25 million volumes, a 500-mile-long bookshelf!

Clearly, the brain is far more advanced than any computer ever

produced. This computer analogy should not be carried too far,

however, because brain organization is unlike anything else

encountered in technology or nature.(3)

Computer designers have attempted to mimic brain structure with

"neural networks," a type of artificial intelligence (AI). Success has

been very limited; one leader has concluded that some facets of our

thinking will never be duplicated by a machine.(4)

Table 1. Memory of various systems in terms of words. (One word = 5

bytes = 40 bits, or binary digits.)

Storage Device Information capacity (words)

1 typed page 300

3.5" double density

compact disk (CD) 40-200 million

Library of Congress

20 million volumes 2 trillion

Brain

25 million volumes 2.5 trillion

Evolutionary Explanations

A.R. Wallace was a natural historian and an acquaintance of Charles

Darwin. In an exchange of letters in 1869, Wallace wrote, "Natural

selection could only have endowed the savage with a brain a little

superior to that of the ape whereas he possesses one very little

inferior to that of an average member of our learned society." Darwin

realized the threat of this statement to evolution, and replied, "I

hope you have not murdered completely your own and my child."(5)

Darwin feared the death of his evolution theory because the human

brain far exceeded his view of early man. Why did the brain evolve

with potential which never has been utilized to its fullest extent?

This "murdered child" threat greatly troubled Darwin in his later

years.(6) Perplexed by what he observed, Darwin described the brain of

even the lowly ant as the most remarkable speck of matter in the

world.(7)

How does modern secular science explain the assumed "explosive

development" of the human brain? Very creatively! One traditional idea

is that man's discovery of complex tools and speech led to higher

thinking and increased brain size. However, this explanation is a

tautology: Which came first, the increased thinking ability or

increased brain capaity? Today there are new ideas emerging for man's

intelligence, some of them quite humorous. For example, consider the

suggestion that early man had his brain "baked" and damaged by

spending too much time in the hot sun.(8) The brain compensated by

evolving additional neuron connections to make up for the deficit.

When our ancestor finally came in from the sun (or perhaps put on a

hat!) his full brain began to function once again!

The Two Brains

One active area of research involves the separate functions of the

brain's left and right hemispheres. These mirror-image halves are

joined together by a massive bundle of perhaps twenty million nerve

fibers called the corpus callosum. The left side of the body is mainly

controlled by the right hemisphere, and vice versa. The left

hemisphere is found to be specialized for language and analytical

problem-solving. The right hemisphere, in contrast, controls visual

and artistic ideas.

A standard secular explanation of this brain division is that the two

hemispheres evolved to provide backup systems for each other in the

event of injury to one side.(9) One might ask, however, why there is

just one division of the brain, when four or six backup parts would

provide even greater survival value. And if the two halves indeed

evolved as backups for each other, then why are they specialized for

different activities? The arbitrary and conflicting ideas of brain

evolution are obvious. Much evolutionary thinking appears to be the

result of dominant right hemisphere activity, where creativity reigns,

and the neglect of the left hemisphere, where logical reasoning

occurs!

Conclusion

The beautiful complexity of our brain contrasts sharply with all

simplistic secular attempts to explain it away. Our brain remains a

frontier of science; we actually know very little about it, but what

is known is overwhelming. In addition, every single neuronal cell

within the brain contains a trillion atoms. This is like a microscopic

universe within each cell, complete with order, purpose, and

interdependence of components.

Many topics related to the brain remain for the creationist to

explore: What could our first parents, Adam and Eve, have accomplished

with the possible full use of their brain potential, before the

limitations of the curse? What damage has been done to science by the

false revolutionary idea that brain size is the sole measure of

intelligence?(10)

The brain truly provides an ultimate design challenge for evolution.

It should be a cause for humble praise in considering the wonder of

the mind. It is a privilege to dedicate these minds to the Creator.

* Don B. DeYoung, Ph.D., is a Professor of Physics at Grace College,

Winona Lake, Indiana; Richard B. Bliss, Ed.D., is Director of

Curriculum Development at ICR.

REFERENCES

1. R. Dawkins, The Blind Watchmaker, Longmans Group, Harlow, Essex

England. 1986, p. 5.

2. M. Denton, Evolution: A Theory in Crisis, Adler and Adler,

Bethesda, Maryland, 1985, p. 330.

3. D. Meredith, Metamagical Themes, Basic Books, N.Y., 1985.

4. R. Penrose, The Emperor's New Mind, Oxford University Press, New

York, 1989.

5. R.M. Restak, The Brain the Last Frontier, Doubleday and Company,

Inc., Garden City, New York, 1979, pp. 58,59.

6. Ibid., p. 67.

7. C.U.M. Smith, The Brain, G.P. Putnam's Sons, New York, 1970, p.

195.

8. K.R. Fialkowsky, "A mechanism for the origin of the human brain: a

hypothesis," Current Anthropology 27(6):288, June 1986. See also "A

half-baked theory of how our brains grew?", Discouer 7(9):15,

September 1986.

9. R.M. Restak, The Brain, Bantam Books, New York, 1984, p 240. 10.

H.B. Sarnat and M.G. Netsky, Evolution of the Nervous System, Oxford

University Press, New York, 1981, p. 398.