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Biological Evolution

Updated: Aug 16, 2021

In the 1859 book On the Origin of Species, Charles Darwin first proposed the theory of evolution. He called it descent with modification. In the modern science the evolution is said to operate on the twin principle of random mutations and natural selection. Darwin, at the time he wrote the book did not know the actual mechanism by which the process of evolution occurs. With the discovery of DNA and it's role in reproduction, we now know how that works. Of course in case of viruses, which do not have DNA, the evolution takes place though other genetic molecules like RNA and proteins. The theory of evolution has been controversial ever since, sometime simply due to honest misunderstanding and sometimes (IMO) intentional misunderstanding or ignorance. In reality it is a very simple and common sense theory and here I will try to explain it in a hopefully simple and understandable language.


First and foremost, it needs to be understood that Evolution is not an intentional/active process that has plans which it executes with purpose and intent. It is simply is what unfolds in living systems where there is a possibility of random mutations that modifies the properties of organisms in a species through generations and the environment in which the generations of organisms find themselves in, ends up with more of the ones that are more fit to survive in that environment to the reproductive age and can pass on those favorable properties. This is why I do not like when scientists use an active, intentional, agency-laden language when talking about evolution e.g. evolution did this, evolution caused that.


Second, the noticeable effects of the process of Evolution on the organisms of a species takes place over a very very long periods of time relative to a single timespan of a generation of the species and over multitude of generations of that species. This of course means that it is relative timeframe. If a species reproduces very fast e.g. virus and bacteria, they will evolve very fast compared to the timeframes humans will consider long long timespans. In fact we are currently (in 2021) suffering from the rapid mutations and evolution of the COVID-19 i.e. delta, delta plus and now lambda variant. The rate of random mutations in a organism is not unlimited. It is important to note that for many random mutations to occur, bigger the population of the organisms, the better. This is why it is important for us to control the population of COVID-19 so that fewer potentially (to us) dangerous random mutations occur.


Third, notice the word random in random mutations. It means that the mutations are not intentional and always good for a species. Some mutations are good and some mutations are bad for the organisms of species for the environment they lives in. If the mutations are all bad and create organisms that are unfit to live in the environment they find themselves in, the population of that species will start decreasing or it may dwindle to the point of extinction. What I said so far is relative to the constancy of environment in which the generations of the species are living. Who is to say that the environment itself will stay the constant. If the environment changes in such a way that the random mutations which were bad previously, are actually good in the new environment the population of the species may come back and even grow tremendously. Also even if there were no bad mutations that turned from bad to good or good to bad, the change in environment can affect the population of species. A simple example of this is that COVID-19 does not survive better in cold weather so there was a hope that the pandemic will subside during winter months. Unfortunately we did not take advantage of that with the implementation (and in case of USA - intentional neglect) of correct healthcare measures, and here we are. Another example is that Polar bears have thick white fur and live in the snowy and cold Arctic region. The white color of fur helps with camouflage and thick fur helps with staying warm in bitter cold of the Artic. So more white fur the better. However, if the climate change kicks in and the Arctic ice melts and the temperatures rise, the thick white fur may become a liability. The Polar bear population may die by overheated bodies.


A sociological point here is that, the knowledge of science of evolution and implementation of medicine and health care based on it is not something to be taken lightly. If we do not heed the findings of science, then we do so at our own peril. Of course, we have to temper the implementations considering the cultural, sociological, economic and political realities. And in case of rapidly evolving scenario of the COVID-19 pandemic, the inertia of our systems and institutions hinders the timely implementation and effectiveness of measures we can take. To be fair, we were taken by surprise by the pandemic. The lesson we have to learn from this is that we need to be better prepared next time and I think we will be, unless of course political malpractice actively sabotages our efforts. That will be an unfortunate, self inflicted wound. Pandemic was a too-fast-to-react-to situation, but climate change is another potential danger looming over slightly longer timeframes and I hope it does not go by the way of too-slow-to-react-to-and-it-kind-of-creeped-up-on-us-and-then-it-was-too-late situation. BTW scientists were warning us about possibility of pandemic and have been warning us about climate change. So we better do something about the climate change now, precisely because it a very slow moving catastrophe which may non-linearly, irreversibly and very quickly get out of hands. I will write more about climate change some other day.


The key points I want to make are:


  • evolution is not a purposeful, goal driven process

  • evolution takes place over long times frames of multitudes of generations.


In this post I wrote about Biological Evolution. I will have more to say about the topic of Biological Evolution and more applicable and relevant Cultural Evolution in future posts.

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