Extinction can be seen as a method that nature employs to curb out species that will not evolve or are redundant in its eyes. By definition, it is a state where no member of a species is alive to carry forward the generation. However, a mass extinction is a phenomenon where 90 to 95 % of all species, which means most life on the planet, would disappear in a very short period of time! These are times when the Earth undergoes immense turmoil; it metamorphoses from the life-giving mother to the life-devouring devil. The destruction helps to create newer species that adapt better, life springs forth again, and the earth finds a way to continue. There have already been five of these cataclysmic events, that is, if we do not count the numerous minor level ones.
In recent years, scientists and environmentalists have argued that a Sixth Mass Extinction, known as the Holocene extinction, is underway due to increased anthropogenic activity faced by the Earth. In the past 100 years, we have seen many species go extinct or become endangered because they have been hunted down or because their habitats have been altered due to human encroachment. Therefore, it is argued that a Sixth Mass Extinction is currently taking place.
At first glance, it seems agreeable after looking at the evidence being mentioned, that, this is in fact true. But when one looks closely at what is going on, we can see that this is not the case. The arguments provided in favor of an ongoing Sixth Mass Extinction can also be used to disprove it! Here I shall argue that, despite the fact that numerous species are slowly moving towards extinction, there is no Sixth Mass Extinction going on at this present moment nor will it be in the immediate future. Moreover, an extinction event that will happen, IF it happens, will not be the doing of humankind, given the fact that humans are also a part of nature.
To begin with, the current extinction rate is not significant enough for it to be considered a mass extinction. The present extinction rate by definition doesn’t qualify, since it is very gradual and not sudden, making the rate quite low. Moreover, the rate is an assessment of background extinction which occurs in nature. Background extinction is the ongoing pursuit of extinction, which is natural and thus does not substantiate the occurrence of a Sixth Mass Extinction. Mostly, the redundant or unfit species are eradicated through natural selection by this process. The factors that lead to mass extinction can manifest themselves gradually, but the phenomenon itself is relatively rapid.
Furthermore, if a mass extinction was in the works presently, then we would not have been able to control it, since the phenomenon is irreversible. It will take its course and then eventually be subdued. The problem is acknowledged by Peter Brannen, a reputed science journalist specializing in planetary sciences, which he describes in his interview with Doug Erwin, a Paleontologist who holds expertise in the Permian Extinction. How Erwin describes mass extinction is like a power grid problem, where failure in one area will propagate into failure in other areas as well. He argues that most mass extinctions happen due to sudden changes in the internal dynamics of food chains which lead to a series of cascading reactions whose penultimate effect is the extinction of animals from a period. The sudden change is however triggered by an external pressure. He argues that once a mass extinction begins, it won’t just make elephants, tigers and other certain species extinct but kill all hardy and ubiquitous organisms like plants, and insects as well. An event like this will affect almost all organisms. This is not happening right now. In fact, we have been able to save some species from dying off and not all organisms have been dying simultaneously.
It is argued widely that there are a lot of ecological pressures acting in nature which may lead to mass extinction, as the life on Earth would not be able to cope with them. Like global warming, which caused by a rise in the level of carbon dioxide and other greenhouse emissions in the atmosphere. Emissions released enormously in nature, however primarily by humans. Moreover, over-hunting, over-fishing and habitat destruction has led to a reduction in a number of species. Even, the introduction of invasive species by humans, that later become dominant in a habitat, may result in a decimation of the native species. All these aforementioned conditions, however, could also create new species, which can possibly postpone mass extinction. The Selfish Gene Theory proposed by Richard Dawkins, can explain how this is possible. The theory suggests that the genes govern how our abilities or phenotypes will be in a given environment. Apart from this, the gene will ensure that the organism survives to retain the gene by evolving its response to a particular environmental threat that the organism faces. The gene, thus, will enable the species to survive. Because of the many ecological pressures that species are suffering, the selfish gene will enable them to attain phenotypes that will help them cope up with the new selection pressures. There have been examples where microorganisms have been observed degrading pollutants that were introduced in nature, because of oil spills or pesticides. Examples include bio-remediators, like worms than can eat plastic! Such traits are still not strong enough to curb out pollution, but given some time the biological mechanism will evolve to be more efficient.
The above mentioned Selfish Gene Theory can also be extended to human’s behavior towards nature, with a similar explanation used by Richard Dawkins to explain the evolution of altruism in his book, The God Delusion. He argues that altruism has evolved as an evolutionary strategy rather than a societal product. He says that the genes code for a character in the organism so that they are either good to their own kin so that the gene copies are benefitted and the gene is retained. Alternatively, being kind or helping another species will help you in return and hence bring in reciprocal altruism at play, again allowing the genes to survive better in nature. From this example, we see that behavior such as altruism has also evolved as a strategy to survive. Similarly when faced with the threat of mass extinction, the genes will alter themselves to code for the behavior called biophilia and trigger humans to save nature. This might seem to be a very optimistic and impossible event but this is gradually happening in the real world. The rising awareness and concern for environment pollution, nature activism and innovations to create products which will reduce the ecological imprint of mankind are proof that these events are in play. Biophilia as the name suggests is the love for nature; however E.O Wilson an American biologist and naturalist describes it as “the connection that human beings seek with the rest of life”. He further states that we have certain needs from nature, and have certain reactions towards it which are genetically inbuilt in us. This aspect of Biophilia coupled with the selfish gene theory, makes it a necessity for the genes to encode for a more positive attitude towards saving the Earth. However, I would like to urge all those literates reading this article, not to become over-optimistic and think that our genes will take care of everything and we should not act; we need to act as much as we can since this is our planet as well.
My claim, that anthropogenic activities will not be the only cause for the inevitable Sixth Mass Extinction, is based on a simple argument- that humans are a part of nature as well. It has been argued that humans are the most invasive species in the world since they have spread out to almost all corners of the world and have enormously exploited nature for their own selfish needs. However, this is how nature works when an invasive species enters an environment where it can survive easily. Plants like -lantana Camara (water cress, in common terms) are also posing a threat to the environment, essentially in the same way as we are. The species escaped its natural habitat and found that the new ecosystem is also perfect for them and hence they exploded in great numbers, much like human history. It is ironical that we see the Holocene intervention separate from nature, as if it is artificial. That can never be the case because we come from nature (and not from Mars or the sky!). We need to think about ourselves as a part of nature, to be able to think about its problems. When we look at the Cretaceous period extinction (where an asteroid impact caused extinction) or the Permian extinction (which happened due to Volcanic Eruptions), one finds that these factors are all external, and it is nature that takes the role to destroy. Be it through the breakdown of food chains as per Erwin or not giving evolution enough time to work, it is nature’s call to make way for mass extinction. All humans can do is aid the process, rather than be solely responsible for it. Besides we do not truly understand how ecosystems work to control the outcomes. We are far inferior to nature than we think we are.
Although there is no Sixth Mass Extinction going on currently, it does not mean that it will never happen. I hope there is more research on the topic of biophilia and its implications to mankind so that our bond with nature is even stronger and our efforts, even more fruitful. Having said that organisms will evolve mechanisms to cope up with the pollution and other stresses that humans are imposing, this does not imply that we need to keep on polluting and damaging the Nature. The goal of this article is to inform the reader that all hope is not lost; things can be done to help our Earth. We are polluting the air, water and land, over-exploiting the Earth’s resources, hunting certain species excessively for our own good; hence it is our responsibility as nature’s beings to save this world which is our home too. From my point of view, there are only two rather contrasting ways to help postpone the inevitable Sixth Mass Extinction. One is to do nothing, which is neither try to save nature nor pollute, let nature repair the damage humans have done while we simultaneously become a harmonious part of nature. Word of caution, this might include the abolishment of culture and society itself. Another way is to be rather active, where we find ways to reduce pollution and also ways to produce less pollution. This can be done by enhancing the bio-remediation mechanisms using our knowledge in the field of genetics and remediation biology. Last but not the least, we can promote and use biodegradable or natural products. The incentive here is to save our homes; nature can make us extinct and replace us, the real question is of whether humans want that to happen or not?