"For the scientist who has lived by his faith in the power of reason,” wrote Robert Jastrow in God and the Astronomers, “the
story ends like a bad dream. He has scaled the mountains of ignorance;
he is about to conquer the highest peak; as he pulls himself over the
final rock, he is greeted by a band of theologians who have been sitting
there for centuries.”
Jastrow’s words come to mind
whenever I hear about professional scientists being obliged to abandon,
or at least to seriously modify, their Darwinian assumptions. From
cutting-edge work in genetics to the latest discoveries in astrophysics,
the evidence is increasingly pointing to one fact: Darwin was wrong.
This
has been impressed upon me recently, as I have been studying the way
culture affects the human brain. Contemporary neuroscientists have been
making some fascinating discoveries about the way our cultural
preoccupations and artifacts alter the physiological structure of our
brains, and, once again, Darwinian orthodoxy is being compelled to yield
to new findings.
Dogs, Pigeons & Beethoven
Let’s begin with a fact that no one
disputes: different species have brains suited to the demands of their
kinds; brain structures differ among species according to need. The
brains of dogs, for example, have a greater facility than human brains
for processing smells, because dogs need a high level of olfactory
acuity to survive in the wild. Indeed, the odor-processing region of the
canine brain is about four times the size of the one in your brain or
mine. Or again, the brains of pigeons have the ability to process
magnetic information, which they use to navigate vast distances
accurately, whereas our brains do not have this faculty since we don’t
need it; we can create and use navigational instruments.
On the other hand, human brains possess structures
that allow us to do all sorts of things that dogs and pigeons cannot,
such as to reason analytically and to appreciate art. It isn’t that no
one has ever tried to teach a pigeon how to do calculus or to
relish the glories of the way Beethoven expanded the sonata-allegro
form; it’s that no one ever could; the pigeon’s brain is structurally incapable of apprehending these things.
Sea Gypsies & Taxi Drivers
Interestingly, what is true as regards the
brain structures of different species is also true regarding the brain
structure of different groups of human beings—though only up to a point.
Still, this fact raises some questions.
Take, for example, the Sea Gypsies, a maritime tribe
of people living off the coast of Thailand. These people have brains
that facilitate exceptionally keen underwater vision. Not only can their
brains override the reflex that normally controls the shape of the
pupil, enabling a Sea Gypsy to constrict his pupils by 22 percent, but
they can also accurately compensate for the refraction that occurs when
light passes through water. To expect a non-Sea Gypsy like myself to
exhibit the same facility would be like expecting a dog to deliberately
bark in F major or a pigeon to coo in D minor.
So how is it that the Sea Gypsies have this amazing
ability? According to standard Darwinian theory, the explanation goes
something like this: over thousands of years, our genetic makeup
gradually changes to conform to the demands of our environments, leading
to appropriate changes in the structure of our brains. Genes that have
survival value will be perpetuated through succeeding generations, while
those that do not will tend to die out.
Thus, according to the Darwinian narrative, because
Sea Gypsies spend much of their lives around the water and survive by
diving to great depths to harvest food, their genetic makeup gradually
came to include these unique capabilities, just as the genetic makeup of
dogs came to include exceptional odor-processing faculties. In both
cases, we are observing the results of gradual adaptation spanning
thousands of years.
But, as I suggested earlier, this evolutionary
narrative has recently had to be abandoned by professional
neuroscientists. We now understand that these types of variations in the
brains of different people groups have nothing to do with genetics at
all. The physiological structure of our brains, including hundreds of
thousands of neuro-connections, do evolve to adapt themselves to our
natural and cultural habitats, but this evolution occurs within a single lifetime without leaving a footprint on the genetic code.
This
was demonstrated through a study of brain scans done on London taxi
drivers in the late 1990s. Researchers found that, in the cabbies, the
posterior hippocampus, a part of the brain that stores spatial
representations, was considerably larger than in non-cab drivers. Now,
clearly, a London taxi-driver’s genetic make-up is not fundamentally
different from a London mechanic’s or a London web designer’s, yet there
are very clear structural differences in their brains.
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