Some Critical Reflections in the Light of Evolutionary Theory
The theory of evolution is considered to be the most important scientific development, only second to the atom bomb, in terms of its impact on the life of human beings. This is not only a unifying theory of biology, but also has far-reaching implications for philosophy, social sciences and questions that were traditionally raised prominently in the domain of religion. The theory was proposed by Charles Darwin, primarily to address the question of the origin of species. In our free time (like lockdown in COVID-19 pandemic), it is natural to ask yourself the philosophical questions like why there are so many types of creatures around us, how they must have originated in the first place, what is the purpose or driving force or mechanism of life. The scientific approach to this question was attempted by many scientists, amongst whom Lamark’s proposition was most accepted one, before Darwin’s theory. According to Lamark, adaptive characters acquired by individuals through practice are inherited to the next generation and next-generation further improve upon it. Through such successive changes in characteristics for adaptation to the environment, a lineage becomes significantly different from the rest, and a new species is created. The only fundamental difference between Lamark’s and Darwin’s theory is that Darwin proposed, changes in inheritable character are random (rather than guided by an individual’s efforts to adapt to the environment). Then this pool of new inheritable characters is selected upon by nature, leading to the survival of the fittest. This successive accumulation of adaptive characters in a lineage will make the individuals quite different from others, leading to the origin of new species. In higher organisms, sexual reproduction mixes the inheritable characters of two individuals leading to homogeneity in the population. Therefore two subpopulations will diverse into two different species only if reproductive isolation is there for some time, like due to geographical barriers. Then the two populations may adapt in different directions and eventually some characteristics will cause the biological reproductive barrier which will define the two populations as different species. This simple process repeated generation by generation on trillions of creatures, for millions of years, can create the amazing biodiversity that we see around us. This lab of nature has ample resources, diverse environments in various pockets of earth, and gradual change in these environments, that all have contributed to the evolution of so diverse creatures.
Unraveling Religious Sects
The theory of evolution gives an explanation of the origin of life and biodiversity which was a domain of religions. This is an important philosophical question that was keeping people spellbound to religious mysticism. Many times, the mystic part of religion is used by individuals in religious authority, for exploiting followers. Most religions explain the origin of amazing and complex living beings around us by invoking the concept of even more complex and capable beings who could build these creatures. These answers are collectively called creationism or design theory. It is an intuitive answer with the analogy of building machines and other complex systems by humans. But It is a paradoxical answer as it will create another question about the creation of that supernatural being. “Creationism versus evolution” is a popular topic of debate in western countries. The purpose of human life and human tendencies is more accurately described by looking at the brain as an instrument for enhancing evolutionary success rather than unfounded propositions of relationship with God. No person, including purified saints, can be free from tendencies that have evolved in the human mind for reproductive success and survival. In the religious order of living beings, humans are shown the superior most. Initially, evolutionary trees also depicted humans at the topmost branch. But all living beings are descendants of LUCA (last universal common ancestor), having taken equal time till today to adapt to their respective environments. Therefore modern depictions of the evolutionary tree are directionless, branching out of the center of a circle. Some creatures are more complex than others, making them more robust in the present environment but complex organisms adapt slower than simple ones in new conditions.
Implications for a healthy lifestyle
Evolution can explain why things are the way they are in biological systems. How various features of a creature make it more adapted to its environment. And this reasoning can be applied at every level of complexity, from molecular structure to human behavior. Hereditary characters, written in DNA, changes slowly, and more so in complex organisms. Therefore, to explain the hereditary characters of humans, we have to take into account the environment of forests where humans have spent a lot of the time before urbanization. According to the concept of EEA (environments of evolutionary adaptation), our liking for sugar was beneficial when we lived in forests, where these high-calorie molecules were rare. The industrialization has made available pure sugar in ample amount but our metabolism is not yet adapted to utilize so much amount, leading to the pandemic of diabetes by hacking the instinct which was originally for the detection of sugar in ripe fruit. Similarly, sodium chloride was also rare in the forest, but it’s important for nerve function, therefore we evolved a liking for it. But suddenly we have ample salt, leading to high blood pressure. Tooth decay and obesity are also diseases caused by changes to which we are not yet adapted. In the forest, we had hard to chew food and had to run after the food or run to save ourselves from becoming food. Recently food-processing and mechanization of work have taken away the natural exercise of gums and muscles. To offset this sudden change in our environment, we shall brush teeth and artificially run. In the forest, the proximity of family members/clan gave a sense of security. The presence of water and greenery around was a sign of ample food. The urbanization is making people live away from greenery and family members, although without really decreasing the security or availability of food. But the instincts evolved in EEA will perceive urban surroundings as stressful. Therefore, picnic-like events and get-togethers are very relaxing.
Implications for happiness
Our brain is a very complex signal processing machine, which also has only one purpose, like any other organ, that is, to better adapt us to the environment. The brain has evolved dedicated modules for situations encountered very often. One such module is the reward system of the brain. It is responsible for our positive and negative feelings like happiness and sadness. Things that make us happy are actually good for our species like eating good food, relaxing, socializing, sex, parental care. Sometimes it is said that our brain is a pleasure-seeking machine but the evolution of the reward system is not for staying happy or sad, but to increase chances of survival. Consciously, we continuously seek happiness but the feeling of sadness also has adaptive advantages. In a sad or depressed state, the person is less energetic, less active, therefore no new action or decision is taken, saving the person from further exacerbating the situation. It is quite similar to the feeling of pain, upon an injury so that movements are restricted which can otherwise further worsen the injury. But taking drugs to increase happiness or decrease sadness will defeat the purpose they are originally evolved for, eventually decreasing the chances of survival. In fact, most of the narcotic drugs are similar in structure to natural molecules working in the brain’s reward system, hacking it in a maladaptive manner. People’s desire for happiness is also exploited by fraud spiritual personalities and motivators who promise to train people to stay always happy or neutral between sadness and happiness. Rather, claims that staying always happy (or neutral) increases performance and achievements, is inconsistent with the theory of evolution. Evolutionary thought is finding applications in a wide range of fields like, molecular biology, psychology, sociology, and even as an algorithm in computer science. The fundamental concept is very easy to understand and does not require any technical knowledge. In western countries, many popular science books have been written on it like The Blind Watchmaker, The magic of Reality, The God Delusion, Unweaving the Rainbow etc. Popularization of this theory will invoke a scientific temperament in people and make them less vulnerable to pseudoscience or deceptions.