The principle of evolution is a theory that justifies the diversity seen in this world, from unicellular organisms to plants, animals, and even humans. Evolution explains questions like how come apes are our closest relatives? Why do giraffes have long necks? It is true that living things change over time and that is due to several factors including environmental challenges and underlying genetic mechanisms. Charles Darwin was famous for his theory of evolution based on natural selection. This theory postulates that unfavourable traits and diseases caused by unfavourable mutations are not passed on to the subsequent generations, a process that requires a million years, at the least. And hence the idea of survival of the fittest followed, where species adapt to their constantly changing environment and therefore only those with the “strongest" genes will survive and reproduce.
Genetic editing has gained fame and support in the past decade, being labeled as “A revolution in psychiatric diseases”, especially with the new promising gene modification tool: CRISPR-Cas9. This one-of-a-kind technology enables geneticists and research doctors to edit parts of the genome by removing, adding or redesigning parts of the DNA. As you are reading this, the CRISPR technique itself is evolving as a technology. It is being used in both animal and human research and is showing great potential in reversing debilitating and even fatal diseases like cancer, heart diseases, schizophrenia and more.
This is great! But has it ever occurred to you that million years of evolution, powered by forces of natural selection and events that we as humans are completely unaware of is now reduced to a single procedure that eliminates "unfavourable" DNA mutations, and restores “normal” functioning? I believe it to be fascinating, but also scary. Most evolutionary processes happen for a reason, and according to the Israeli history professor Yuval Noah Harari, we are “far too ignorant and weak to influence the course of history to our own advantage”. But is that entirely true?
Many scientists nowadays argue that there is no such thing as a “normal" brain. Many traits that are observed in psychiatric disorders like psychopathy, narcissism, impulse-control, anxiety, and phobias are in fact adaptive traits that are useful in our diverse societies. For example, a person that is more likely to take risks than others is the one that will thrive in challenging situations. Those that are more likely to experience anxiety are those that are highly motivated to prepare for this presentation or study for that exam. Indeed, there are evolutionary disadvantages to suffering from psychiatric diseases, however, there is some kind of evolutionary advantage in having the trait. Similar discussions concerning what is considered an advantage or disadvantage in psychiatric diseases will indeed raise more questions of the utility of genetic editing in the treatment of psychiatric disorders.
In the 21st century, we have dropped the 'natural' from natural selection. Our selections are far from natural and far too subjective, subjective to our own species and not to the whole ecosystem that we belong to. Evolution is not Homo sapiens specific, it is not even species specific. It is for all.
Katherine C. Bassil