Through the efforts of Gregor Mendel, and other researchers, the science of Genetics has become a well-advanced body of knowledge that aids in the better understanding of the human anatomy. Because of these advancements, all aspects of the human population have been greatly affected and thus changed significantly. Medicine, for example, was altered drastically as the familiarity on how the human anatomy operates is better understood. Through this, mortality rates have decreased significantly and people live much longer than was once considered normal.

The understanding of the concept of heredity was advanced in a small monastery by a monk who was interested in how different traits were transmuted in plants. The monk, Gregor Mendel, who crossbred peas with different phenotypes, found a variation of probable traits. These findings resulted in the better understanding of heritable phenotypes and the genotypes that causes it. The basic concept of the genotype is based on two traits, namely the dominant and recessive traits. The expressivity of the dominant (D) traits is such that, whether a pair of dominant (D, D) or a singular (D) allele is found within a chromosome, that phenotype will be expressed because of its dominance. The recessive (d) traits, however, vary because in order for the phenotype to be expressed, both alleles in the chromosome has to be recessive (d, d).

The expression of phenotypes that result from different combinations of alleles in the genotype is mainly affected by the DNA composition in that organism. The DNA, or deoxyribonucleic acid, is the main component of the human anatomy’s structural determination. Through the constant replication of some of the DNA’s parts, the systems, constructs, and other sections of the body is consistently maintained.

The DNA is made up of three parts, namely: sugars, phosphates, and bases. Furthermore, these four bases bond together in specific pairs (cytosine bonds with guanine, while adenine bonds with thymine) in which the sequences of attachments determine the amino acid to be formed. During translation, a series of these base pairs form and with the help of a protein called protease II, mRNA is produced. This is done by the protein recognition of the start portion in a gene sequence by locating thiamine and adenine repetitions (which often marks off the start of a gene sequence). The series of bases which forms the mRNA, also known as a codon, is then translated thus becoming a polypeptide hence resulting into a specific amino acid. This process is mainly determined by a triplet code that starts the series (adenine-urisil-guanine) and a series that terminates the gene sequence (urisil-adenine-adenine, urisil-adenine-guanine, or urisil-guanine-adenine). In between these triplet codes, large sub-units of ribosomes, methyanine, and other amino acids binds with the tRNA that elongates the codon thus resulting into a specific protein.

As established above, triplet sequences of nucleotides are important in the determination of protein types that the eukaryotic body produces. However, only three percent of the human genome actually provides blueprints for proteins. Because of this, many believe that the ninety-seven percent that do not encode anything are vestigial and therefore can be designated as “junk-DNA” (Schewe, 1994, #1). Also known as introns or non-coding DNA, the junk-DNA is said to be the amalgamation of once important nucleotide sequences that became obsolete as eukaryotic cells evolved farther and farther into more advanced forms. Because of this notion, many then claim that these nucleotide sequences are rudimentary and just form at random and are useless therefore parasitic (for they just take up space and nutrients). However, through the help of other bodies of science, such as physics and linguistics, this notion can now be dispelled.

Investigators of the chaos theory who turn to patterns called fractals manage to find order in the midst of such unpredictable events. Due to the seemingly random configurations of the DNA, these structures can also therefore be considered fractals. Keeping this in mind, a number of scientists attempted to find recognizable patterns in “junk” DNA that can provide information about its possible function.

Some of these researchers, namely H. Eugene Stanley of Boston University, and Wentian Li of Rockefeller University, claim to have found such arrangements (scitec.auckland.ac.uz, #1). They state that “patterns can be observed because incidents in the system can be correlated with a previous occurrence and thus a configuration can be spotted despite of the seemingly chaotic backgrounds” (#2). Because of this, some can therefore say that the positions of the nucleotides ( adenine, cytosine, guanine, and thymine) in a DNA sequence is dependent on the nucleotide that precedes it.

Borrowing from the work of a linguist named George K. Zipf, Stanley and a few of his colleagues ventured to study “junk” DNA even further by determining the frequency of certain bases and finding out how often these nucleotides appear in a sequence. Through this, they were able to determine that “junk” DNA contains three to four times the redundancy of an exon (coding DNA) with a 1/f co-relation. This co-relation therefore makes “junk” DNA similar in pattern with most human languages (#3). With this knowledge, they were then able to theorize that these so-called “junk” DNA may have something to do with efficient information storage. This is because long, repetitive chains often safeguard against erroneous information storage.

Another recent study that dealt with the determination of the purpose of the intron is done by studying the genome of a prokaryotic, photosynthetic organism called the Crytomonads. Because these organisms exist with immensely different cell sizes, it is important to determine what influences such variations. If one takes a close look, it can be observed that the nucleuses of these organisms are greatly proportional to its cell size. Through countless hours of research, scientists were able to ascertain that the size of the nucleus is similar to the amount of “junk” DNA present. This therefore implies that the intron may actually have a role in establishing the size of the nucleus which in turn determines the size of the cell (jps.net, #1).

In addition to these possible functions, the relationship between exons and introns may also provide clues to the introns likely purpose. Through genetic engineering, the studies of these relationships were made possible and a conclusion was therefore made. The experiment was performed by placing an exon in a vertebrate gene with two different sized introns. The result was that: when the introns were large, the large exons were skipped, and when the introns were short, the same large exons were included in the transcription. Through these results, it can therefore be established that the non-coding introns control the recognition and, therefore, the transcription of the protein-coding exon (#3). This means that phenotypes of organisms may be controlled in part by non-coding DNA.

In my opinion, as the possible functions of the non-coding introns are enumerated above, people should end the erroneous notion that these nucleotide sequences are useless and even parasitic. However, because of the long-standing belief that these chains are worthless, it is almost impossible to alter the thought patterns of so many people. This idea can be readily observed with the unchanging notion that structures such as the appendix, tonsils, and other such examples, are rudimentary and therefore vestigial. This long existing belief still survives today despite the overwhelming evidences that prove otherwise.

In conclusion, through Mendel, and other researchers, the science of genetics evolved into one of the most important bodies of knowledge that contributes to the betterment of human living conditions. Through this science, life expectancies were elongated, understanding of the human anatomy was expanded, and the overall increase in health was achieved. In fact, even in the entertainment industry the various concepts of genetics are often made reference to (ie. the title of the movie GATTACA actually shows a sequence reading guanine-adenine-thymine-thymine-adenine-cytosine-adenine). Despite of these however, there are still questions that genetics still has not made concrete answers to (so far). One of these queries is whether the so-called “junk” DNA actually has a function. Initially thought of as a vestigial accumulation of rudimentary DNA that resulted from millions of evolution, the “junk” DNA is now receiving better attention from scientists thus resulting into its better understanding. Through these studies, the introns are now believed to function in a variety of ways: First, it can possibly be the determining mechanism of what phenotype can actually be expressed (for it affects what exons are transcribed). It can also quite possibly be the more efficient sequence storage space for information for it shows patterns of the initial chain affecting the next (such repetitive and long series prevents errors in memory storage). Hence, through these examples, it is therefore possible to conclude that the so-called “junk” DNA is not junk at all and that it is actually an integral portion of the human anatomy.

Internet, Noisy Nucleotides, www.scitec.auckland.ac.nz/~king/junk.htm

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