Evolution From A Molecular Perspective


Introduction: Why globular evolution?

Evolution has been a heavily debated issue since Charles Darwin first
documented the theory in 1859. However, until just recently, adaptation at a
molecular level has been overlooked except by the scientific world. Now with
the help of modern technology, the protein sequences of nearly every known
living thing have either been established or are in the process of establishment,
and are widely accessible via the internet. With the knowledge of these
sequences, one can actually look at several organisms genetic codes and point
out the similarities. Entire genomes of creatures have been sequenced, and the
human genome project is well underway and ahead of schedule. With this new
knowledge comes worries, for humans, however. What if the information stored in
our genes was available to the public? Would insurance companies and employers
base their selections on these traits? Also, with the total knowledge of every
sequence of every amino acid chain in a person\'s genome, couldn\'t a laboratory
perceivably reconstruct an exact copy of, or clone, that person? These are all
issues that will have to be dealt with in the near future, but for now we need
only concern ourselves with the objective observation of these proteins in our
attempt to explain our ever mysterious origin. As humans, we are the first
creatures to question exactly where we came from and how we got here. Some
cling to religious creationism as a means, while others embrace the evolutionary
theory. As of now, and possibly forever, neither can be proven to be absolute
truth with hard facts, and both have their opposing arguments. The point of
this paper being composed is not to attempt to abolish the creationist view, a
feat that at this point seems impossible, but merely to educate those seeking to
unravel the mystery of our forthcoming by pointing out facts that exist in the
modern world and that can be quite easily and independently researched. It is
conceivable that the two ideas, creationism and evolutionism, can exist
symbiotica lly due to the fact that both views have very good points.

Hemoglobin: Comparisons between species

Of all the proteins in living things, hemoglobin is "the second most
interesting substance in the world," as American biochemist L. J. Henderson once
stated (Hemoglobin, 4). However bold this statement seems, it must be realized
that hemoglobin is, at least in the scientific world, by far the most studied
and most discussed substance in the human body, as well as in other living
organisms. Hemoglobin is the carrier in blood that transports oxygen to our
tissues and carbon dioxide out of our body, changing colors as it does so.
Hence, hemoglobin has long been termed the pigment of our blood. Hemoglobin was
one of the first proteins to be purified to the point where its molecular weight
and amino acid composition could be accurately measured. This finding was very
important in that it eventually lead to the understanding that a protein is a
definite compound and not a colloidal mixture of polymers. Each molecule was
built from exactly the same amino acid subunits connected in the same order
alonga chain, and had exactly the same weight. Most organisms have their own
unique, individual chain of proteins to make up their hemoglobin, but all
organisms share certain similarities, so striking that they are unable to be
ignored. Let\'s take, for example, the first twenty-five amino acids in the
alpha hemoglobin chains of 7 different animals: a human man, rhesus monkey, cow,
platypus, chicken, carp (bony fish), and shark (cartilaginous fish) (See Table
1.1.) As is shown, the variations increase the further apart the organisms are
on the proposed evolutionary scale. A human man differs from a rhesus monkey
only twice in the first twenty-five amino acids of their alpha hemoglobin chains,
whereas a man and a cow differ in three areas. This is the product of many
thousands of years of natural fine tuning, if you will, through the slow but
precise processes of natural selection and adaptation. The fact of natural
selection shows us that while most genetic mutations usually prove fatal, a slim
few are ac tually beneficial, and assist the mutant in living and procreating
offspring. This assistance helps the mutant-gene\'s frequency grow in the gene
pool and remain there since all progeny possessing this certain trait are going
to have an advantage over the other organisms lacking this quality. This is the
basis for evolution. The higher a certain species is on the evolutionary scale,
the more advanced that organism is due to a slight change in the amino acid
sequences of certain