Species Extinction in Prehistoric Wilderness

Discussions about species extinction today often seem unprecedented, yet Earth’s history shows that biodiversity loss and its subsequent recovery have always been part of the dynamics of prehistoric wilderness. Cycles of massive collapses and long-term recovery have shaped the planet over hundreds of millions of years. This introductory post focuses on the connection between prehistoric wilderness, major mass extinctions, and the remarkable ability of life not only to survive, but to expand and diversify after each collapse.

The Five Major Mass Extinctions

Earth’s geological history records five major mass extinctions, named after the geological periods in which they occurred: the Ordovician extinction (about 444 million years ago), the Devonian extinction (about 372 million years ago), the Permian extinction (about 252 million years ago), the Triassic extinction (about 201 million years ago), and the Cretaceous extinction (about 66 million years ago). Each of these events caused a dramatic decline in diversity at both the species and family levels. The largest collapse occurred at the end of the Permian, with up to 90–95% of species disappearing, while the Cretaceous extinction ended the age of dinosaurs due to an asteroid impact. These events illustrate how prehistoric wilderness responded to natural catastrophes of immense scale.

Recovery and Change After Collapses

After each major collapse, ecosystems went through long periods of recovery. They did not return to their previous state but gradually developed new structures. Recovery resulted from evolutionary innovations, adaptations, and the filling of vacant ecological niches. These processes not only restored life but also led to a significant increase in overall biodiversity. Geological records show that with each epoch, species diversity expanded substantially — from the proliferation of fish and terrestrial plants to evolutionary radiations of reptiles, birds, and mammals. A typical example is the rise of mammals after the Cretaceous extinction, when they gained space for dynamic expansion and diversity increased sharply.

Extinctions in the Pre-Human Era

All five major mass extinctions occurred long before humans appeared, and natural processes controlled the development of life on Earth. Catastrophes caused by intense volcanism, climate changes, fluctuating sea levels, or asteroid impacts shaped prehistoric wilderness without any human intervention. These natural geological cycles show that past wilderness was an extremely dynamic environment, alternating between periods of collapse and subsequent evolutionary expansion. They also provide an important contrast to the present, where ongoing extinction is driven not by natural forces but by human activity.

Extinction as a Driver of Evolution 

Although mass extinctions represented dramatic turning points in the history of life, they also created space for new evolutionary lineages. After each collapse, ecological niches were freed, allowing new or previously marginal groups of organisms to expand. These periods saw major evolutionary innovations and massive increases in species diversity. In the long term, despite extinctions, biodiversity grew, because each collapse created conditions that triggered new waves of evolutionary expansion. The result is today’s extraordinarily rich biodiversity, a product of hundreds of millions of years of repeated extinction and recovery.

Conclusion

Earth’s long history shows that collapse and recovery are inseparable parts of the dynamics of prehistoric wilderness. The five major extinctions dramatically reshaped the planet, yet they also allowed the rise of new life forms and the gradual increase of biodiversity to what we see today. Understanding these cycles is key to comprehending the development of ecosystems and the essence of wilderness. This post is the first part of a series, with the next posts focusing on the current biodiversity collapse – the so-called sixth extinction, driven not by natural forces, but by human activity.