Genetics is a fairly recent branch of science, but which has had, in its short period of existence, a significant impact on many aspects of our history.
At the base, genetics tries to answer one of the most important questions about our existence: who are we?
Through the study of inheritance first, and then of genetics, scientists have tried (and still try) to unravel the mystery of life, analyzing what makes us what we are.
Just as computer science has the bit as a fundamental unit and physics has the atom, genetics is based precisely on the study of genes .
The origins of genetics
It all began in the mid-nineteenth century, when Gregor Mendel, an Augustinian monk who lived in Austria, began experimenting with pea plants to try to establish how the characteristics of a particular plant were passed down from generation to generation.
Until then, the prevailing theory wanted that the physical characteristics of an organism were transmitted entirely by the father (seed) and that the mother organism was nothing more than a sort of incubator for the paternal seed and that it did not transmit any kind of genetic information. .
Mendel found that the information needed to create an organism is transmitted by gene pairs, one of which is inherited from the mother, one from the father. He also discovered the mechanisms through which the dominant and recessive characteristics manifest themselves from generation to generation. His work laid the foundation for what would have been the study of genetics in later centuries.
The next big step in the study of inheritance was made by Charles Darwin, who thanks to his observations formulated his famous theory of evolution. For the first time, man had to face the possibility that it was not a supreme being who created him in his image and likeness, but that it was a long process of transformation.
Phase 1: observation
The first phase of the history of genetics was therefore dedicated to observation, to the understanding of how the characteristics of an organism derive from the parents and how they are transmitted.
These discoveries soon emerged from scientific circles. The idea that some character traits could be predicted, such as intelligence or schizophrenia, was soon used as a pretext to identify, and often lock up and torture, individuals who had a history of mental illness in the family. The belief was actually that “non-normal” or socially acceptable behaviors were the product of completely hereditary factors and that they had nothing to do with the conditions in which an individual found himself living, such as poverty, abuse, etc. .
Precisely in this period, and on the basis of these ideas, we started talking about eugenics or the intervention of society to prevent the spread of these traits deemed unacceptable.
Genetics and the road to the Second World War
In Europe, these ideas were adopted and taken to the extreme by the Nazi movement, which with the idea of ”purifying” the Aryan race, gained power in Germany, giving way to the Holocaust, costing the lives of millions of Jews, exterminated in concentration camps. Only after the Second World War was this horror stopped.
With the defeat of the Reich, the atrocities committed in the extermination camps came to light. What had been done using scientific progress as a pretext was very serious and genetics suffered the heavy condemnation of world public opinion. It took a long time for confidence in this field to return.
However, although slowly, the study of our genetic material has continued and important discoveries have been made, such as the composition and function of DNA. The study of its double helix structure has led to a greater understanding of biological processes and the transmission of information necessary for their development.
Phase 2: from observation to manipulation
With sufficient knowledge of the functioning of DNA and genes, scientists quickly moved from the observation phase to a more advanced one: manipulation.
The first approach was to try to “check” the type of information transmitted to an organism, taking it from one and “grafting” it into another: the first experiments on cloning were born.
The argument was, and still is, extremely controversial. On the one hand, science is struggling to try and find cures for some of the worst diseases that afflict man; on the other, the idea of being able to clone a human being brings with it many doubts and implications.
Create a map of a human being
Technological progress and the discoveries of the last decades have made possible a knowledge of nature, evolution and man who until a couple of centuries ago was unthinkable. One of the most ambitious projects was launched in 1990: The Human Genome Project – the Human Genome Project. It was an international collaboration whose purpose was to “map” human DNA, recognizing and classifying the genes that make up our genome. The project ended in 2003 and led to several key breakthroughs in the sector.
For some, this event represents the pinnacle of the study on genetics, but for many others it is only the beginning. In the next few years, genetics could completely change the existence of humanity.
A new definition of normality
Traditionally, medicine has a very particular approach regarding the definition of normality. The behavior of a healthy body is defined after studying what happens during an illness. Normality was defined as the absence of known pathologies and was therefore always subordinate to their knowledge.
The Human Genome Project, thanks to the tools and technologies used, has allowed for the first time to overturn this approach, exploring parts of our nature that are not related to disease or suffering.
This new approach can help us understand the problems related to memory, culture, identity, sexuality. This led to a change of trajectory in genetics. If up to the Human Genome Project, the evolution of the field had been linear, now we begin to see a sort of thematic fragmentation, with different branches that develop independently of the others.
The differences and similarities
Our genes contain our history. By studying them closely, it is possible to reconstruct not only the history of our family and our ancestors, but the history of humanity. In particular, the study of part of the cells known as mitochondria , which has its own DNA, has led to great discoveries.
The first finding is that, within the human population, genetic variance is extremely small, for example compared to what we can observe in chimpanzees. This means that man is a relatively recent species, born about two hundred thousand years ago.
Another discovery concerns our origin. Indeed, it would appear that all humanity originated in a small area of sub-Saharan Africa. Our ancestors would all live in the same region and slowly, small groups would move away, detaching themselves and reaching the rest of the globe.
The third discovery is related to the transmission of mitochondria. They are transmitted exclusively by the mother. This means that they can be used to rebuild a sort of family tree. Just this reconstruction led to the discovery that every human being today was born of a common ancestor, which scientists have called “mitochondrial Eve”.
Phase 3: the birth of a new type of survivors, The Previvors
Perhaps one of the most surprising examples of how genetic progress has an impact on our lives is highlighted by the ability to identify genes that can lead to the development of certain diseases in an extremely precise way.
We can take the BRCA1 gene as an example. This gene, which deals with DNA reconstruction, can undergo a mutation which, in many cases, is linked to the development of breast tumors. A woman who inherits the BRCA1 gene in one of her mutations has a much higher risk of developing breast cancer. Thanks to this information, tests have been developed that can detect the presence of this mutated gene, unequivocally identifying the subjects most at risk. However, it should be noted that the mere presence of the gene is not in itself a guarantee that a tumor form will develop, but only indicates a higher level of risk.
This type of test is usually prescribed to women in whose family there is a history of breast cancer cases. When the result of the test is positive, it is often chosen to intervene surgically, with the removal of the tissues at risk. So it was for example for Angelina Jolie, the famous actress who, after discovering that she inherited the mutated gene, decided to undergo a double mastectomy to reduce the risk of disease.
The scientific world has coined a new term to identify individuals in similar situations, who decides to undergo preventive interventions that could save their lives: previvors – from the union of pre- and survivors (survivors).
What the future brings us
What if we could change our genetic code? Who are the teachers, who are the victims? Who would control knowledge, and how would it change the way we live? How would our societies, our children, ourselves change?
Over the past twenty years, the progress that has reached the field of genetics allows us to intervene directly on human genes, coming to alter the state, the physiology of man.
The observation of nature presented us with philosophical dilemmas, related to character, sexuality, intelligence. The ability to manipulate it, however, brings possibilities that we would never have foreseen before.
The idea that it is possible not only to predict the presence of certain characteristics, but also to manipulate the genetic code of individuals in order to eliminate some or insert others, opens much deeper debates on what could be the future of our species, and on who should have the power to make certain decisions.