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| Philippine Eagle |
The cornerstone of the Theory of
Evolution of Charles Darwin is the natural selection. This idea within the
Evolution theory was an adaptation of the “survival of the fittest” theory of Thomas
Robert Malthus in his famous work An Essay
on the Principle of Population. The natural selection is defined as the
process in which from one generation to the next, the struggle for resources
(Darwin called this as “struggle for existence”) will favor individual creatures
with some variations over others and thereby change the frequency of traits
within the population. Moreover, the traits that confer an advantage to those
individuals who leave more offspring are called adaptations.
It rests on complex suppositions. Some theorize that individual organisms adapted
to their environment and this equipped them with certain features for survival
and reproduction, citing for example the case of the giraffes on how they
develop long necks. However, some opine that the natural selection does not try
to supply what an organism “needs”, for example, that a snake would eventually
develop wings to avoid its predators. It means that the organisms do not
constantly have a progressive development. They deny that the natural selection
produces “perfection” to the organisms. They speculate instead that the natural
selection is the simple result of variation, differential reproduction, and
heredity. For them, it is a mindless, goalless, and mechanistic process.
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| Philippine Tarsiers |
But for Charles Darwin, the
formation of the new species is the result of the natural selection through which
favorable variations or the well-adapted organisms would tend to preserve,
while those unfavorable ones would be destroyed or doomed to extinction. The
natural selection is the theory that accounts for the divergence of species
from common ancestors and thus for the endless diversity of life. This means
that as individual organism adapt to their environment, each organism separately
or independently change itself, creating new species. If this true then there
should be different innumerable species. The evolutionists will surely retort
that this will not happen in a lifetime but in a span of million years. Let
us take as an example that of the dinosaurs. They appeared and roamed on earth
approximately 230 years ago, and became the dominant terrestrial animals for
135 million years. They became extinct 65 million years ago. The extinction may
not be a result of adaptation and natural selection since they were the
undisputed predators. The widely accepted theory presupposes that all dinosaurs
became extinct as a result of a meteor crash on earth. But according to the
Wikipedia, the birds survived the extinction event that occurred 65 million
years ago, and that these birds continue the dinosaur lineage to the present
day. If this true, then there is no evolution in this case, but devolution. How
do the gigantic, fierce dinosaurs “evolve” into the birds we know today?
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| Philippine Spotted Deer |
On the other hand, Ayala opines
that the natural selection increases the frequency of the genotypes that have
better biological efficacy and that efficacy and adaptation must frequently go
together because if it is the other way life on earth would have been extinct a
long time ago. According to this theory, furthermore, in
order for natural selection to operate on a trait, the trait must possess
heritable variation and must confer an advantage in the competition for
resources. If one of these requirements does not occur, then the trait
does not experience natural selection. If this is the case then the birds we have
today could not be results of an evolution of the ancient dinosaurs for it would
mean the loss of that superior biological efficacy.
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| Butanding |
Here are some of the other limitations
of natural selection.
The first is the lack of necessary genetic variation. It means that the natural
selection can only operate on the genetic material already present in a
population of organisms. It cannot create new genetic information and subsequently change
one kind of organism into another. The second
limitation according to the article Understanding Evolution is the constraints
due to history. It explains that the basic body form of mammals is already laid
out in their genes and development in such a mutually constrained way that is
unlikely to be altered. The third limitation is the trade- offs according to
which changing one feature for the better might change another for the worse.
The example of this is that longer legs would mean greater speed but it could
be hazardously delicate, that is, easily breakable.
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| Philippine Civet |
Just like in the Theory of
Evolution in its totality, there are varied and even contradictory opinions.
Moreover, there are a lot of inconsistencies in them. Many theories oppose each
other and refute the validity of each other. But the different theories on
Evolution collectively agree on the thesis that life is a ramification from a
common ancestor through gradual genetic changes for million years. But one
question that the Evolution theory could not satisfactorily answer is how do human
beings develop their rationality, their capacity of decision-making, their
culture, etc. Is the rational nature of man a result of the adaptation and
natural selection? Will snails, worms, or even planktons have a
rational nature million years from now? Will they be developed into rational
beings? The answers to these questions here will just be based on mere speculations.
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| Philippine Tamaraw |
If natural selection produces
changes in the genetic composition of a population from one generation to the
next, then organisms become better adapted to their environment, does it mean
that there will be constant and endless change of species? If human beings have
the same ancestors with the apes, does it mean that the monkeys and apes that
we have today come from ancient primates that failed to evolve? But evolution
means to have superior biological efficacy. Failure to evolve means extinction.
How come there still exist animals of lower forms? Do their ancestors failed to
evolve, and how come they continue to exist? This theory could never unlock the
mystery of life. Though valuable in science, a theory that remains on the level
of speculation should never be considered as truth.
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| Charles Darwin |
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