Fiona Wong, Grade 12

From the humans that swarm the world’s bustling city streets, to every blade of grass lining our front lawns, all of these organisms are made of DNA – and all forms of DNA are composed of four essential building blocks: adenine, thymine, guanine, and cytosine (1). The key differences that contribute to human individuality lie in our DNA sequences; genes code for a unique protein, and each protein is expressed through a unique physical phenotype. Astoundingly, the percentage of DNA shared between humans is 99.6%. However, the remaining 0.4% represents millions of nucleotide pairings that truly make up who we are (2).

With each additional generation, humanity’s genomes are rapidly diversifying. Each generation results in genetic recombination, the process in which ancestral DNA is passed down from each of your parents. The constant genetic swapping results in variations between individuals, and under certain circumstances, can lead to the development of entirely new species.

Our genomes have arisen from ancestral lineages: after all, new mutations can only arise through the recombination of pre-existing DNA. At least, that is what most geneticists believed in the past. Contradicting the geneticist Susumu Ohno in his 1970 novel “Evolution by Gene Duplication,” new research has found that de novo or ‘orphan’ genes with no line of heritage to trace have increased in frequency over time. Many models have been established to explain this phenomenon, but the widely accepted explanation stems from the process of natural selection (3). One example of this model is present in Anne-Ruxandra Carvunis’ thesis of the ‘proto-gene’ mechanism. In her paper, these stretches of DNA that aren’t programmed to be transcripted into proteins eventually do so through genetic mutations. Over time, if these unintentional proto-genes code for beneficial traits, the genes will become a staple in the organism and persist for future generations (3). This contributes to the growing evolution of our species as a whole: because our environment is always shifting, natural selection will continue to pick out the most advantageous genes for survival. And because humans are found in such diverse environments, there’s always a need for this process.

Despite to the multitude of differences between our genomes, there are over 70 million people worldwide suffering from a form of genetic disease (4). While individual diseases are rare, the lasting impacts of these conditions are challenging to treat. With the development of new advancements in genetic studies, scientists have been able to utilize “gene therapy” techniques in order to prevent the progression of these diseases. The continued study of the human genome is crucial to these developments, as many gene therapy techniques require the precise cutting of pre-existing DNA or insertion of new strands in specific areas (5). A single mistake can have disastrous and lasting effects: which contributes to the growing controversy surrounding these developments.

If we have the ability to shape our genome to change any aspect of ourselves, what’s stopping humanity from using this technology in selfish ways? If we have the power to change our eye color, skin tone, and height as we’d like, how would we distinguish ourselves from our peers through our “imperfections” if there aren’t any? These beliefs stem from the science fiction aspects of this field. Currently, most gene-editing research is geared toward improving society as a whole, treating genetic disorders, and preventing the inheritance of those traits in future generations. The potential benefits of these technologies are balanced by controversies, however. Genetic engineering is attributed to playing “God” with our future. Genetically-engineered offspring, or “designer babies” with desirable traits could potentially create a world of inequality and superiority. While these concerns seem far-fetched at this time, the ethics of this field have led to heavy scrutiny that “holds back” genetic engineering research.

With each new generation as our population grows, the human genome is becoming more diverse and riddled with millions of combinations of expressed genes. However, the human genomes are still 99.6% similar to each other, distinguishing our species from other living creatures on Earth. This game of genomic rescrambling will always have a common denominator: we’re all part of the same population living on the same planet. No matter how many changes our genome undergoes, the 0.4% of DNA that differs is minuscule compared to the rest of the sequences. Our eye color, skin tone, and personality traits make each individual unique in some way, but at the end of the day, all of us are still human. We’re part of ‘one humanity’ despite our genetic differences, which is something that none of us should ever forget. Now, more than ever, it’s crucial that we realize this vital fact and work towards a brighter future together, innovating ourselves but staying true to who and what we are.

References
[1] National Cancer Institute. (n.d.). DNA. Cancer.gov.
[2] Toledo, C., & Saltsman, K. (2012, June 12). Genetics by the Numbers. Nigms.nih.gov, (2012).
[3] Callier, V. (2020, April 9). Where Do New Genes Come From? Quantamagazine.org, (2020).
[4] Bluebird Bio. (n.d.). Impact of Genetic Diseases. Thegenehome.com.
[5] Bluebird Bio. (n.d.). Basics of Gene Therapy. Thegenehome.com.