When Biodiversity Plummets and Life is Lost: Mass Extinctions

by | Oct 19, 2022 | Animal Books, Guest Article, History | 0 comments

Photo by Marcus Lange

With Nicki Geigert’s photo book of rare and endangered animals, readers will get to know a panoply of exotic and beautiful species and learn more about them before they might be lost forever.

An estimated 8.7 million species live on Earth, most falling under the phylum Arthropoda. With that mind-numbingly large number, scientists would have to spend thousands of years just cataloging them. Yet, tens of thousands of species are lost yearly; and the number is only increasing due to human-fueled climate change. Wildlife photographer Nicki Geigert has been capturing what is still present, chronicling animals in their natural habitats or on the move before they disappear, never to be seen by the next generation. Geigert’s photo book of rare and endangered animals has preserved these creatures, and perhaps in the future, people will learn to take more care of what they have.

What Are Extinctions?

Extinction is when a species dies out: the last member, an endling or a terminarch, is confirmed dead. It is a common occurrence and is necessary for new life to be propagated and ecosystems revitalized. By itself, extinction is a sad affair but ultimately part of the overarching cycle of life.

When multiple extinction events happen simultaneously or within a short period, there is a cause for concern; an extinction event is also a natural part of life and can be because of any number of natural calamities. Extinction events have sometimes contributed to the explosion of evolution. The loss of several particular species can open up new niches for other animals to take advantage of and inhabit. 98% of all life that has ever existed on Earth is now extinct.

Scientists have a consensus that extinction events are frequent occurrences, but data is insufficient to provide a concrete answer. Regardless, in an extinction event, the world changes, whole ecosystems are lost, and new ones are created.

The Five Great Mass Extinction Events

In the 3.7 billion years that there has been life on Earth, five great mass extinctions have profoundly affected life’s direction.

The Ordovician-Silurian event happened 443 million years ago, killing almost 85% of all species existing at that time and might have happened because of lower temperatures, which allowed glaciers to form and the sea level to drop. Three hundred seventy-four million years ago, the Devonian mass extinction event wiped out more than half of the world’s species. A medley of environmental changes is attributed but not confirmed; it could have been because of fluctuating temperatures or the reduction of oxygen and carbon dioxide in the atmosphere. Then there was the Permian mass extinction 250 million years ago, considered the most extensive and catastrophic, resulting in a monumental 95% loss of all species. No one knows why it occurred, and hypotheses range from massive dust clouds blocking the sun to an enormous volcanic eruption that turned the oceans toxic. And then, probably because of the tremendous geologic activity happening in the period, the Triassic mass extinction, taking place some 200 million years ago, eradicated 4/5ths of global biodiversity.

The Most Recent and Most Popular

Lastly, the most recent and popular mass extinction event, the Cretaceous extinction event, occurred because of an asteroid hitting the Earth. The globe was ravaged by the prolonged winter caused by the asteroid’s impact, stopping photosynthesis and killing nearly 80% of the total species in that period. The Cretaceous event is well-known because it was the event that ended the dinosaurs. In the popular psyche, when they think of an extinction event, they think of what happened at the end of the Cretaceous.

The Sixth Mass Extinction Happening Right Now

Not all mass extinction events happen in weeks. It’s safe to say that most mass extinctions occur over several decades, which is very short compared to billions of years of life. So, it might be a surprise to know that a mass extinction event is happening right now.

The sixth mass extinction event is the Holocene extinction, after the current geological epoch. Still, it can also be called the Anthropocene extinction after its leading cause, humanity (which the Ancient Greek word for is ἄνθρωπος or anthropos). The principal contribution of humanity to the ongoing mass extinction event has been climate change, which has led to the destruction of habitats, the transformation of ecosystems, and the overexploitation of natural resources. 

What Can Be Done About It?

Join environmental groupsvolunteer with wildlife conservation programslearn more about climate change and its effects, and pressure politicians to enact ecological policies.

Do your part to change the world for the better so that everyone can see the animals in Geigert’s photo book of rare and endangered animals. 


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