"ARTIKEL BAHASA INGGRIS BIOLOGI" What Evolution Is
By Paul Claybrook
The Theory of Evolution began with Charles Darwin and his book, Origin
of Species. Interestingly, he did not conclude that evolution began
billions of years ago in a chance combination of just the right
chemicals. He simply observed that many species were similar enough that
they appeared to come from a common ancestor. Despite its "evolution"
into what it is today, it has become the default scientific explanation
of the origin of life.
To understand evolution, one must understand the difference between the
origin of life and the tiny changes that we do see happen and are
clearly happening. The origin of life is thought to have taken place
billions of years ago when the earth was rather young and was bathed in
water and a plethora of simple molecules that included carbon, nitrogen,
oxygen, iron, chlorine, etc. In other words, the ingredients of life.
It is believed that with the aid of energy from the sun, these chemicals
combined in various combinations and every once in a while, or maybe
just once, the one in a million chance (so to speak) would cause a
combination that could be classified as primitive life giving molecules.
Eventually these combined to make more complex molecules until they
formed into what would be considered a very simple cell of come sort.
Now of course it is thought that even basic molecules were very
uncommon, and the more complex they became the lesser and lesser chance
they had of forming, but that the one in a billion billion billion
billion, etc. ended up as a cell. Of course this took place over
millions of years, it is not supposed to have happened in a short time.
However, for some random reason, a tiny fraction, or perhaps even just
one of these few primitive cells, through pure chance, happened to have
the ability to divide, which it began doing. Soon there were lots of
these cells and as they filled the ocean, natural selection began to
take effect and most of them died off, but every once in a while, one
would have a mutation that allowed it to adapt a little better and
therefore reproduce.
It is this natural selection that we see every day. We know for example
that wolves were the original ancestors of dogs. This is an example of
evolution, just evolution that humans forced. Every once in a while, a
wolf was a little tamer than normal and then bred to produce offspring
that were also tame. Over many generations, they became what we call
dogs today. There are also clear similarities between animals in
different places because their environments demanded slightly different
survival properties.
These distinctions are important because no one is positing that species
can't change over time, but many deny that life could have come from a
pool of non-living molecules purely by chance. So when you say that you
don't buy into evolution, you don't usually mean that minor attributes
of species cannot change over time, you mean that you don't think life
originated with a pool of slime. Not understanding the difference can
make it seem that you do not know what is evolution.
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