Letter to my Daughter
Sunday, 3 November
 |
| Lungfish |
Good Morning Jessicca…
Nothing is static so long as there is the dimension of time
involved. All things known to the human
mind are in constant transition. The universe
is expanding. Gas clouds deep in space
condense into stars. Stars age and go
cold or are consumed by black holes. The
galaxies move and swirl about. Our solar
system does the same about our star, the sun, which itself is a captive rider
on a course set by our Milky Way. Our
planet Earth, provider of all that is needed to sustain life, is in constant
change. The land forms, projecting above
Earth’s liquid surface, inch slowly about the globe – gathering together into
new formations, eventually to be pulled apart before, once again, reforming
into new configurations. Ocean currents
change their flow, as does the axis of this planet’s rotation, creating new
climate patterns. Every life form able
to sustain itself over the span of ages must have within it the capacity to meet
the challenges that change with time. Adaptation
is an ever present dynamic of life. It
is the merciless economics of nature.
We change – you and I.
We call it growing up, early on, but then we settle for just witnessing
our own body growing old. Aging is
transition. We live for a time, and then
expend ourselves. The resources I once
called ‘me’ are freed up for new and interesting other life forms to use to
sustain their own moment in the sun. We
are the product of many ancestors who once dreamed as we now do. We are like them because we carry their
traits. Go far enough back in time and
our ancestors look less like we do now. Our
own species has improved in its abilities over time. Our rise to the top of the animal kingdom has
been extraordinary. You and I are living
examples of a broad category of animals known as mammals. One gender of this species has the capacity
to carry a forming life within it and also internally manufacture all the
nourishment the new life will need once born.
We call this gender ‘Mom’. She
protects within her body this new person – a baby if human, a puppy if she is a
dog or colt if she is a horse. In every
case the new being begins as a single cell.
The cell splits and these cells grow before they also divide from one
into two cells. The cells take on
specialized tasks and the new life begins to show different characteristics and
constantly refines them until it finally, one day, emerges. Look at the baby! How wonderful it is. The baby gives us its total trust. It is powerless to do otherwise. We must not let it down. We are overwhelmed with emotion. We give the baby our devotion. We pledge it our very lives. It is that
important that new life should one day replace old. The baby must grow and gain wisdom so that it,
too, will one day fulfill its biological destiny and bring forth new life to
replace its own. This is the manner in
which life is sustained on Earth.
The necessary change that must occur to life over the
generations cannot be accomplished in a manner of one individual regenerating
itself as a new copy. New life, at a
complexity beyond microscopic cellular existence, requires the intimate
interaction of two life forms giving of their traits in order to produce one
new existence exhibiting the combined characteristics of the previous two. Surprising new dimensions of an old formula
may arise from this process. Variations in
abilities among individuals within a population enhances the chances a species
will survive dangerous new environmental challenges. The offspring of the survivors retain these
adaptive characteristics and we say the species has evolved.
Climate change can be one factor in the slow drying up of a
large body of water. It means extinction
for most, if not all, forms of fish inhabiting their shrinking watery
world. Yet, there may be hope if a fish
has, for instance, the characteristics of the modern-day lung fish. Its gas bladder serves as a rudimentary lung,
replacing for short periods of time, dependency on gills for gas exchange. It’s lobed, meaty fins serve as vestigial
legs, poor locomotion over land but it may get the animal to the next available
pond. The lung fish survives areas of
drought by seeking out depressions that still retain water.
The earliest forms of amphibians may have had similar motivation
and capabilities when they first ventured above the water’s surface and
squirmed onto land. Unlike the lung fish,
though, these vertebrates discovered a new world rich in resources. Without competition, plump insects and lush
vegetation was theirs for the taking. A
husky animal with thick fins, capable of moving over land, has attributes
poorly suited to compete with fast, nimble fish. But its rudimentary terrestrial abilities are
game-changing assets that enable it to exploit an environment teeming with new
possibilities. Success on land leaves
them only one powerful reason to return to water. Their young require a watery environment during
the first stages of their life.
Eventually this new niche for life becomes heavily populated
with individuals competing with one another for food and other resources. One obvious characteristic that improves one’s
chances for survival would be improved locomotion. All else being equal, an animal that is
faster and moves with less effort is more likely to enjoy a full stomach. The animal is also more likely to survive to
have offspring. These young will share
their parents’ adaptive characteristics.
Over the generations competition among animals of the same species
provides survival pressures that select for a fin’s bone structure to become
one whose configuration is more suitable for walking.
Today’s amphibians are well suited for their environment but
they remain tied to water for reproduction.
They become scarce in arid climates.
The first vertebrates free to lay its clutch of eggs in a dry location
could once again exploit a rich niche free from competition. The egg shell didn't magically come about
overnight. It had to be the result of
long and slow refinement, much as the bone anatomy of the fish’s fin served as
the basis for the terrestrial leg. Once
again competition for resources provides the selective pressures that drive
biological improvements. The animal best
adapted to its current environment is the one most likely to live and reproduce;
ensuring the characteristics that best aid survival will be represented in the
next generation of individuals. This is
the biological meaning of the phrase ‘survival of the fittest’.
Today’s winning asset is the human intellect. The human being has, in the space of a few
short thousand years, come to be the unchallenged, dominate ruler of this
planet on the basis of human reasoning alone.
Like the first amphibians on land we have no competition except for
ourselves. Yet, our advantage goes far
beyond that of any other animal species’ success prior to our own geologically
recent appearance. We are the only
species to inhabit this planet Earth that can accurately claim that we are the
master of our own destiny. Should our
future status be imperiled we have only ourselves to look to for blame. It’s the responsibility we have taken on when
we became the top of the pyramid.
Love,
Dad
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