From the dawn of the Paleolithic era to the present day, humans have carved out the ability to control their surroundings. Switching to agriculture from a hunter-gatherer lifestyle, was one of the many milestones that eventually paved the way for the grand future to come.
During the agricultural revolution, humans began to experiment with techniques to grow the crops they desired. They would find plants that tasted good or provided beneficial nutrition and breed them to get more such plants. Over time, the wild forms of these plants became rare to find and the domesticated plants became plentiful. This ability to grow useful plants on a larger scale, allowed early humans to escape the nomadic lifestyle and take food production and availability into their own control.
As time went by, humans realized that along with crops, animals could also be bred to express the traits they desired. The best example of this are dogs. Early societies realized that different dogs had different characteristics. Certain dogs had a greater sense of smell, and thus were better trackers while others were better at listening to commands and used for herding sheep. They soon began to breed the dogs that proved most beneficial to them in order to ensure that these traits were passed on. Through these forms of selective breeding, unknowingly, we began to impact not only our evolution but the evolution of the organisms around us as well.
Ghost of Genetics Past
The first scientific breakthrough to explain the impact of selective pressures on evolution was Charles Darwin’s theory of natural selection. His work studying the finches in the Galapagos displayed the impact of land separation on the natural evolution of these finches. As each island had different forms of food, weather and terrain, different forms of finches began to thrive on each island. According to Darwin, fitness is a measure of successful reproduction rather than higher intelligence, speed, etc. Let’s go back to the example with the dogs. Imagine a forest with a group of large, strong dogs and a group of small, weaker dogs. The larger dogs are more likely to thrive due to their ability to hunt for food and scare off their smaller neighbors in turn making them more fit as they will be able to reproduce more rapidly and provide for their young. Now let’s assume that a human settlement arises in the same forest, cutting down the trees and scaring off the prey. We now have a group of cute small dogs that like to play with the new human immigrants and a group of large ferocious dogs that often attack the farm animals. Humans are more likely to hunt the larger dogs as that would both eliminate a threat to their community and provide food for their families whereas the small dogs in turn are cared for and raised as pets. Such a change environment will eventually lead to a decline in the large dogs and a rise in the small dogs leading to a higher fitness of the small dogs. As a highly respected scientist of his time, Darwin’s theory spread like wildfire and the race was on to decipher the basis of natural selection.
Soon after Darwin’s theory of natural selection, a man named Gregor Mendel presented an idea that would set the basic groundwork for modern day genetics. Mendel was a friar, who entered the monastery in order to receive a free education. Inspired by the professors in his university, Mendel began to conduct research on the heritability of traits in pea plants. After years of research and testing almost 30,000 plants, Mendel came to two important conclusions: 1) each individual has 2 copies of a trait inherited from each parent and 2) the traits could be inherited independently of one another. Mendel's work went highly unrecognized until the early 1900s when some scientists rediscovered Mendel's work on the laws of inheritance while trying to develop their own theories to explain the phenomenon.
Once scientists realized that through the proper observation they could determine dominant and recessive traits, they no longer had to rely on luck or coincidence to develop strains of species that displayed the traits they wanted. At that time, this idea greatly impacted the agricultural industry where they could take the crops that produced the most yield or the desired yield and cross them to achieve the results they desired with higher efficiency.
The ultimate key to unlocking the mysteries of genetics came in 1911, when Thomas Morgan proved that it was the chromosomes in the cells that carried genes. Morgan and his students did many experiments on fruit flies to prove this point and also to show that genes located close to one another on a chromosome were inherited together, in a phenomenon called genetic linkage.
1 2 3… Let the Race Begin!
In the following century, scientists chased their tails trying to produce new varieties of species by genetically modifying DNA in various methods, from radiation to injection of bacterial vectors. You may have heard the term GMO also known as Genetically Modified Organisms. GMOs often get a bad reputation in media, but the organism itself is neither good nor bad. A GMO is any organism that been modified with foreign DNA. For example, in the 1970s, scientists were able to insert the gene that produces human insulin into bacteria to create synthetic insulin. This invention has been vital to treating many diabetics around the world. However, most of the taboo arises with genetically modified food. Many people believe that eating GMO food is harmful; however, just being genetically modified does not make food any more harmful than traditional. Issues are only likely to arise if unintended genes are introduced to a plant, but to ensure public safety, GMO crops have to go through stringent policies to ensure their safety. More often than not, they are modified to not spoil as fast, maintain color, or produce a certain taste.
So by now, you are probably wondering why I am taking you down memory lane…
Understanding the basis of genetics is important. Science fiction has often alluded to a world of genetic screening and manipulation. While it may still be a possibility, we are nowhere near achieving that. The focus of the scientific community currently is to model diseases effectively. Imagine that a present day computer got transported into the middle ages and after some time it began to have issues, the humans of that time would have to figure out how this machine was originally built, what part may have broken down, and why that part may play a part in the issue at hand in order to find an apt solution. That is analogous to the situation we are in now. Up until now, the job was to figure out how our traits were coded and passed on and now we are working on why these instructions result in our given traits of interest. The field of genetics has become the center of the biological sciences within the past century. From ecology to psychology, the ease of acquiring genetic data has made it a central key to bringing together all the fields that have a history of fighting one another to prove their various theories. In the past 2 decades, scientists have uncovered the genes involved in over 6,000 disorders. But this is barely a start! Some of the most debilitating diseases such as Alzheimer’s and cancer are a result of many small genetic variations that add up to exhibit the variety of phenotypes seen in patients. We are slowly finding those variations, commonly referred to as risk factors. As we begin to figure out why these diseases are occurring, we can use the knowledge to develop cures.
Currently, the bottleneck in the field is the data analytics. As the cost of acquiring genetic data continues to go down, the number of genomes sequenced goes up. While this may sound good in theory, in reality this leaves us with large amounts of data and limited tools to analyze them. It is like trying to fix a laptop with a hammer and a wrench. Over the past decade, the need for data science in the field of genetics has skyrocketed. So the race is on, once again, to develop the most efficient tools to analyze the copious amounts of genetic data acquired.
In time, if we are able to decode the functions of all the genes in the genome, it could give humans more control over themselves and their environment than ever before. But for the time being, the focus should remain on modeling diseases and devising personalized treatment plans crafted for the patients.