The Sixth Extinction

The Sixth Extinction
April 3, 2020 No Comments Environment and Health Ariel Sykes

The Sixth Extinction: The Duty of the Dominant Species to undo an Ecological Downfall

By Erin Green

A catastrophic event is underway. We are in the midst of the Sixth Mass Extinction, a modern and human-made extinction. The megafauna category is defined as large animals in a comparable or larger mass than humans, and the extinction of the megafauna group is the main concern of the Sixth Extinction. This extinction started around the time of human’s arrival to the new world, which is equivalent to about 13,000 years ago. Now, we have less than half of these species left. In the past century, scientists have begun to infer that these extinctions can be traced back to human activities, more specifically habitat destruction and the overexploitation of animals.

Table of Contents


A 100 years ago in the Mangrove swamps of eastern India, tigers could frequently be found roaming the Sundarbans. More specifically Bengal tigers could be found, which are a subspecies of tigers that are apart of the megafauna group and are considered to be the apex of the food chain because they are a top predator. But this tiger is not just another species. They are critical to our ecosystem because they help to maintain the delicate balance between prey and vegetation and without them the entire ecosystem would be at risk of collapsing. But Bengal tigers are currently one of the top species on the endangered list. Their population lies at around 1,400 and about 99% of this species has gone extinct.

The anticipated extinction of Bengal tigers can be largely credited to the Sixth Mass Extinction, or the extinction of the megafauna group due to the Second Order Predation theory, which connects the arrival of humans in the new world to the extinction of many larger mammalian species. More specifically, there are distinct human activities that contribute to this extinction.

When examining mass extinctions we must also look at how the future of the ecosystem will be affected. In relation to this, there are the negative and positive impacts of the anthropocentric lens, which is a environmental and philosophical lens used to examine humans’ place in the biosphere. When thinking about ethics in connection to this topic we will look at the duty of humans to protect animals, with a focus on the ethical values of justice and security. I will also focus on the legislation implemented in the United States that acts to protect both humans and animals, and possible future legislation that could act as a solution to the current extinction problems

Background Information

Megafauna is a specific classification of animals that derives from zoology. Animals that fit into this classification are large mammals whose size is either larger or of a comparable size to a human. Specifically, mammals that range from 40 to 1,000 kilograms (88 to 2,204 lbs) are considered to fit the megafauna classification. A main characteristic of megafauna is that they have slow growing populations but also low death rates due to their lack of predators. Many scientists hypothesize that the recent high extinction rates found among the megafauna can be traced back to the recent increase in human exploitation in conjunction with their slow growing population (“Megafauna”).

Sixth Mass Extinction

Currently scientist propose that we are in the midst of something called the Holocene Extinction period, more commonly referred to as the Sixth Mass Extinction. While this event is incredibly complex the first step in understanding it is understanding what a mass extinction actually entails. An extinction event is:

“… Any time in the history of life on Earth during which the process of dying out of a species happens at a faster pace than the evolutionary process of species formation– due to, obviously, deteriorating conditions for life, in general.”


Our current scientific epoch, which is a specific division of time marked by important events, is the Holocene epoch. Prior to this epoch there have been 5 confirmed mass extinction events, starting from around 440 million years ago. From these 5 extinctions scientists have developed the pattern that mass extinctions usually occur about 62 million years apart. The last extinction event was the Cretaceous extinction which took place around 66 million years ago and eliminated 80% of species that existed at the time. Scientists infer that an asteroid was responsible for wiping out around half of the marine organisms as well as the vast majority of dinosaurs. Because of the pattern scientists have developed and the timestamp on when the last extinction took place, we can infer that we are nearly 4 million years overdue overdue for another mass extinction (Wagler).

The Sixth Extinction In Relation to Megafauna

More than 90% of all species that have once lived on earth are now extinct. While this quantity seems large this still leaves around 2 million discovered species alive today, with countless more undiscovered species. The normal background extinction rate is one to five species going extinct every year, but the current background extinction rate is 100 to 1,000 times higher. This alarmingly high rate is largely attributed to human activity, and scientists have concluded that rates would be around 1,000 times lower if humans were not in the picture. Before human arrival to the new world “less than a single species per million went extinct annually”  (Dell’Amore). On the Union for Conservation of Nature’s red list there are 27,000 endangered species, out of a total of 98,512 species assessed. This means nearly 3/10ths of all assessed species are considered endangered. More specifically, over the past 100 years there have been severe declines in the megafauna populations in particular. One study concludes that:

“Between 1900 and 2015, nearly half of 177 surveyed mammal species lost more than 80 per cent of their distribution. Billions of populations of mammals, birds, reptiles and amphibians have been lost all over the planet, prompting scientists to suggest we have now entered a sixth mass extinction akin to a ‘biological annihilation.”


This annihilation of megafauna in particular will have severe effects on our ecosystem, which is a topic that I will explore more in depth later in this paper.

Gerardo Ceballos Study

An ecology conservation research professional in Mexico, Gerardo Ceballos, has been instrumental in researching this topic. He recently ran a small sample study that points to large species extinction. The sample size consisted of 177 different species, the majority of which were large mammals and/or species that fit the megafauna characterization. Ceballos called his findings a “global phenomenon”. In his research he discovered that 75 of the species in the study experienced a population loss of over 80%, and that every species considered had at least a 30% loss of land which can be inferred as a loss of habitat. These findings point to greater trends in “global-population losses” and clearly indicate that a dire extinction event is taking place in our environment (Simon-Lewis). Because of these findings, as well as many other studies that indicate similar trends, it is clear that the Sixth Mass Extinction is a current crisis that must be stopped. In order to stop this catastrophe, however, we must figure out the cause.

Homosapiens in Relation to the Ecosystem

400 years after humans’ arrival to the world there was a significant reduction in the prey and predator ecosystem. Scientists labelled this trend the Second Order Predation Theory, which is explained graphically below. The populations of predator and prey were reduced by about 1.5%, which may seem small but significantly altered the ecosystem at the time. This theory also has a direct effect on the predator and prey ecosystem balance. Because humans began to hunt predators as prey, not only did many predator populations drop but predators were also forced into hunting different prey. Humans became the dominant predators in the system and as a result of this herbivore and vegetation populations began to fluctuate unnaturally (Whitney-Smith). Furthermore, upon reviewing fossil records from about 200,000 years ago one study found that “before humans evolved, less than a single species per million went extinct annually” (Dell’Amore). This drastically differs from the current extinction rate which, as previously mentioned, is at least 100 species per year. It is abundantly clear that when humans entered the world they caused an abrupt change to the ecosystem, but the Sixth Extinction has shown that in recent years this change has become even more substantial. This is primarily due to human activity.

Counter-arguments against this theory

Because the Sixth Extinction is such a new and radical event, many scientists have proposed alternate theories to the Second Order Predation and human activity theory. The main alternative is the Climate Change Theory. Some believe that climate change is the biggest and sole factor of extinction. But many scientists pointed out that regardless this would still point to human activity as the issue because we are still causing the drastic effects of climate change. Others have attempted to argue the Sixth Extinction as a whole because they believe that extinction is a natural process of species formation which has not changed since humans’ arrival to the world. But this statement is proven false by Second Order Predation Theory which shows the substantial change in extinction patterns after human arrival. Some even attempt to argue the positive impacts of extinction, stating that the earth could not support the survival of all animals and that extinction allows for a balance between predator and prey ratios. While portions of this statement are true, balance between predator and prey is largely due to death and birth rates, the rate at which extinction is happening is causing instability in these ratios. In turn, this instability has the potential to lead to the collapse of the ecosystem, something I will delve into further later in my paper.

Human Activity

During the Cretaceous Extinction an asteroid wiped out most of the living species at the time. In this scenario we are the asteroid (Kolbert). Human activity is, in fact, the main cause of the Sixth Extinction, with habitat destruction and overexploitation being the two main activities that support this theory.

Habitat destruction is an indirect cause of extinction and it is defined as: “a natural habitat becoming incapable of supporting the native species”

(Habitat Destruction)

Habitat destruction is considered the biggest threat to wildlife, as well as being a threat to 85% of species on the endangered list.

In fact, “many species, even those apparently well protected, are dying out slowly as their habitat is destroyed.”


Habitat destruction takes place due to the degradation of land by homosapiens. Humans often use this land for agricultural expansion, food production, industrial expansion and extraction of natural resources. But a change in habitat can unnaturally shift the ecosystem that animals inhabit depleting the food, water, and shelter that they need to survive. On the other hand, a more direct cause of animal extinction is overexploitation.

Overexploitation is defined as “harvesting species from the wild at rates faster than the natural population can handle.”


More simply put, overexploitation is the killing of animals often for either sport hunting or use as a commercial resource. Globally, hunting and trading have become the biggest overexploitation activities. Many animals are illegally hunted for parts, such as their tusks or hooves, and then sold to various practices around the world. Megafauna in particular are often trophy hunted because of their large size. This becomes detrimental to many megafauna species because their populations are unable to recover due to their low birth rates. These activities have had detrimental effects on species thus far, and statistics show that if we do not put a stop to these practices it will only get worse. As of 2018, scientists predict that 59% of all megafauna will be on the road to extinction by the 22nd century (IUCN). And while these extinctions alone are negative events, their effects run even deeper.

Impacts of extinction

While one out of two million may seem small, the loss of one species has the ability to impact an entire ecosystem. This pertains even more heavily to megafauna due to the fact that they are apex predators, meaning that they lie at the top of the food chain. When one species goes extinct the entire food chain shifts as well. The population of prey to predator becomes unbalanced, and with no predator able to consume the prey, the preys’ population will at first rise but then experience a significant drop due to limited resources for consumption.

This will have an immediate effect on food chain biodiversity which is critical because “greater species diversity ensures natural sustainability for all life forms.”


As more animals die out the biodiversity within the food chain will lessen, which means there will also be a lack of alternate food sources for the living species to consume. Eventually the food chain would collapse because of instability in predator to prey ratios, and with each food chain disintegration the ecosystem would be closer to collapsing as well. In conclusion, it is very clear that the loss of one species is detrimental to the entire ecosystem.

Philosophy and Ethics

When examining an ethical issue it is important to consider all stakeholders and lenses involved. A critical lens to consider when exploring environmental ethics is anthropocentrism.

Anthropocentrism is “a world view that considers humans to be the most important factor and value in the Universe. In contrast, the biocentric worldview considers humans to be no more than a particular species of animal, without greater intrinsic value than any of the other species of organisms that occur on Earth.”


This lens allows us to examine humans’ place in the biosphere, view human action from a new perspective, and create connections between humans and the environment.

If we consider this view to be a positive lens then it would allow us to consider the instrumental value that earth provides us with. We would then be able to view earth as a resource and a means for our own survival because it would only contain value to us. We would have access to all its natural materials, including plants and animals. Viewing anthropocentrism positively would allow for the continuation of our social development and progress. We would be able to disregard our concern for any other entities and instead continue with our current way of life. Furthermore, because anthropocentrism places us as the most important factor in the universe we would then also be considered the dominant species. This idea of the “dominant species” largely stems from the anthropocentric lens and it is one that we as humans subscribe to because we subconsciously view ourselves as the most important entity in the universe. But when we subscribe to this notion of the dominant species we also raise many ethical questions such as:

  • Does this assign us with a duty to protect other animals?
  • Or does it mean that we must only look after our own species?

Contrastingly, if we view anthropocentrism as a negative lens it would then point out all the damage that we are unjustly causing not only to animals but to the environment as well. Using the earth as a resource would no longer be fair because we would no longer be considered the dominant species and therefore we would have the same value as any other living thing. This would mean that all species are equal and that instead of treating other animals as disposable we would need to protect them. We would also view animals as having intrinsic value, which is the value they contain by just existing. Additionally, the lack of biodiversity caused by human activity would be seen as an ecological crisis that we would need to reverse, not only because it affects the resources available to human race but also because of the negative impacts it has for other species.

The issue with these conflicting viewpoints is that they both would have drastic effects on the world we live in. The idea of anthropocentrism is already so heavily integrated into our society it would be very difficult to live without it. But accepting it wholly would lead to the downfall for other species and ourselves. Instead, we must find a less radical view that will allow us to benefit ourselves but also protect other species at the same time.

Ethical Dilemma

This notion of finding a middle ground leads me to my ethical question: is it ethically permissible to assign humans with the duty of saving the megafauna? We can analyze this question by looking at two values, security and justice.


Security is the state of not being exposed to danger or harm. This value would let humans act for the welfare of their own species and examine the duty we have to protect ourselves. It would let us use not only the earth, but also all animals as a tool for our own survival. This would let us continue our current lifestyle as well as allow for social progress and development regardless of the effects it could have on other species. Security views anthropocentrism as a positive lens that will benefit all generations of humans. The United Nations Charter is an example of legislation that protects the security of humans.

This charter protects “conditions of economic, social progress and development”  as well as identifies “the human person as the central subject, participant and beneficiary of development.”

(Charter of the UN)

This legislation, however, ignores the future repercussions of development. In fact, the drawbacks to this view could include the collapse of the whole ecosystem as well as the decline of the human race due to the depletion of resources. Because of how fragile the ecosystem is the extinction of one species would most likely have effects on all living things, including the human race. In conclusion while security may seem like the view that most benefits the human race, it could actually have dire effects in the future.

Justice, on the other hand, is the act of being just or fair. Justice dismisses the anthropocentric lens in favor of righting the wrongs that humans have caused. With human activity being the main reason for extinction, justice would include enacting laws to protect animals as well as adjusting our lifestyles to stop the use of animals as a resource. To be fully just to animals we would have to figure out a way to undo the damage we have done with previously extinct species, as well as put a stop to the Sixth Mass Extinction. In total, being just would include a change in lifestyle for humans as a way to preserve other species. In the United States there are two main pieces of legislation that focus on justice and protection for animals– the Endangered Species Act and the Animal Welfare Act.

The Endangered Species Act, also known as the ESA, “by law requires protection for critical habitat areas and the development and implementation of recovery plans for listed endangered species.”

(Summary of ESA)

From there a program is developed for the conservation of endangered animals and the habitats in which they are found. This act is one of the most effective acts in the United States, with billions of dollars going to animal preservation each year.

Next is the Animal Welfare Act, also known as the AWA, which is the only federal law in the United States that “sets standards for the humane care and treatment for certain animals that are exhibited to the public, sold for use as pets, used in research, or transported commercially.”

(Animal Welfare Act)

The AWA establishes requirements concerning the transportation, sale, and handling of certain animals. However, this act only pertains to a small number of animals and often lacks protection for animals that need it. Many times these acts also lack repercussions for violating their terms. It is clear by the high extinction rates that the current animal protection legislation in the United States is not entirely effective and needs to be improved if we want to put a stop to the Sixth Extinction. In the long run the value of justice as well as increased legislation could be beneficial to the human race because it would protect our ecosystem from collapsing.

Both of these values relate back to the overarching concept of duty. Duty can be described as a moral obligation or a legal responsibility. This idea of duty also leads to more complex questions like what are we legally required to do versus what we morally should do. As humans we must feel a duty to protect other species, by either offering them our protection or by not causing them any direct harm. Specifically, we must feel a duty to the megafauna species. We value them instrumentally as being a needed part of our food chain because they are critical to our survival. But we also have a duty to protect the species that without human activity would not be going extinction. Regardless of whether we consider the anthropocentric lens or not, we must act to save the megafauna.


The question then arises: what can we do to fix this problem? Legally the first step is increasing endangered species efforts. This proves to be difficult because we do not have the resources to save all animals, due to a lack of money and time. But by developing a criteria to examine the value of different animals we could try to benefit as many as possible, while also benefiting ourselves. Furthermore, we must enact laws that limit habitat destruction as well as overexploitation, due to the fact that these are the two biggest contributors to current species extinction. In doing so we must provide repercussions to people’s actions if they violate these laws, as a way of guaranteeing ethical behaviors. In order to protect the human race as well, we must designate certain areas where humans can still obtain necessary natural resources. By creating guidelines we will be able to preserve the development and progress of the human race without hindering the current lifestyle of people.

We must also take action ethically in order to stop this problem from happening again in the future. Humans must become more aware of what they are doing as well as reexamine the impact of their actions. In regards to anthropocentrism, we must change the mindset of humans in order to move away from the idea of the “dominant species”. This in turn will allow us to start being more conscious of our actions and their effects. In the long run moving away from the anthropocentric mindset will allow us to see the value in all other species which is critical because we depend on them for our survival.


The Sixth Mass Extinction is an event that most are unaware is taking place. But as the dire effects of this issue come to light we must examine what we can do to not only fix the problem, but also to prevent something similar from taking place again. The Global Deal for Nature was proposed as a supplement to the 2016 Paris Climate Agreement. It wants to “promote increased habitat protection and restoration, national and regional conservation strategies” (Dinerstein). The goal of this deal is to stop the extinction crisis from taking place while simultaneously allowing for human livelihood to continue as is. This deal is revolutionary in its ideas because it forms a compromise between the two most important stakeholders in this ethical dilemma, humans and the environment. If it is passed and funding is secured then the human race will be on the right path, both morally and environmentally, for the first time in many years. But in conjunction with this deal come many critical philosophical ideas that need to be further explored. The first is the persistent idea of using the earth as a resource. As humans we naturally perceive ourselves as the dominant species, and we subconsciously choose to use earth’s natural resources without thinking of the consequences this may have. But the continuation of this mindset is almost guaranteed to lead to the downfall of the human race because following this framework will quickly extinguish the resources we need to survive. In order to truly make a long-term environmental impact we must change how we value and see the world. The other philosophical concepts that must be reevaluated are the following two questions: Should moral obligations become legal and should animals be given rights, similarly to how humans are given rights, in order to protect them? My answer to the initial question relates back to the idea of humans as the dominant species. As long as we continue to view ourselves in this way I do think that our duty to animals should increase. Outlining these duties with laws would ensure that the protection of animals takes place. Now this does not mean that all moral obligations should become legal, but in this instance I do believe that the only way for action to be taken is to provide legal standards for protection. The following question, however, is much more complex. Because animals do not have a voice and are not consider biologically equal to humans it would be extremely difficult to grant them rights. Instead we should focus our efforts on protecting them from harm, not only harm caused by humans but other factors as well. In conclusion, it is important to realize that our next steps in regards to the environment are critical. All members of society must become more educated and aware of what is happening to our ecosystem in order to save not only our planet but also ourselves.

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