If you want evidence of the very first mass extinction event on Earth, begin by looking below your feet here in Fillmore County. Most of us live near limestone from the Late Ordovician Period. The diversity of ancient life (fossils) you may find significantly diminishes as one moves into younger rock formations. This is because 85% of species that were alive during the Ordovician Period went extinct in a short period of time, literally causing the end of an entire geologic period.
A University of California study from 2015 illustrates that life on Earth existed 4.1 billion years ago, pushing back the previously recognized age of 3.8 billion years. Since then, there have been five mass extinction events, where life on Earth was almost extinguished in a relatively brief time. Extinctions are ongoing throughout the fossil record, so what’s the difference between a mass extinction and background extinction?
According to dictionary.com, a mass extinction event is: “The extinction of a large number of species within a relatively short period of geological time, thought to be due to factors such as a catastrophic global event or widespread environmental change that occurs too rapidly for most species to adapt. At least five mass extinctions have been identified in the fossil record, coming at or toward the end of the Ordovician, Devonian, Permian, Triassic, and Cretaceous Periods. The Permian extinction, which took place 245 million years ago, is the largest known mass extinction in Earth’s history, resulting in the extinction of an estimated 90% of marine species. In the Cretaceous extinction, 65 million years ago, an estimated 75% of species, including the dinosaurs, became extinct, possibly as the result of an asteroid colliding with the Earth.”
This is different than background extinction levels which are defined by the same website as: “The ongoing extinction of individual species due to environmental or ecological factors such as climate change, disease, loss of habitat, or competitive disadvantage in relation to other species. Background extinction occurs at a fairly steady rate over geological time and is the result of normal evolutionary processes, with only a limited number of species in an ecosystem being affected at any one time.”
We are living in the 6th mass extinction event. Whether we’re in its midst or just its dawn is a question for paleontologists and current extinction researchers. A Stanford University study from 2015 illustrates that even the most conservative estimates place extinction levels today at a rate 100 times higher than what is considered background extinction norms.
There has even been a study of the studies on the loss of biodiversity. Published on September 12, 2018, scientists amassed almost 13,000 scientific articles from the last 15 years and proclaimed no additional scientific data is required to recognize the fact of such biodiversity loss, and that the only way to expect any change is for political action. Within the summary of the article: “Their initial conclusion is indisputable: the remaining threats to biodiversity today were already identified nearly 40 years ago, when they were quoted the ‘evil quartet.’ They are (i) habitat destruction (ii) overexploitation of resources, i.e., overhunting or overfishing for example; (iii) introduction of invasive species; and (iv) co-extinctions that may be triggered by these factors. To these four well established threats we may add the concern of climate change, which further destabilizes natural environments.”
The article concludes: “The major obstacle is the demand for concessions even more favorable to resource exploitation rather than to nature protection, despite timid scientific recommendations.”
Because humans are more dependent on biodiversity than many perhaps realize, Gerardo Caballos, a lead author from the Stanford University study states: “If [biodiversity loss] is allowed to continue, life would take many millions of years to recover, and our species itself would likely disappear early on.”
There isn’t a debate in the scientific community that the current loss of biodiversity is extremely dangerous to the survival of our own species. Recognizing this as a priority is crucial but tough, because who wants to hear it? And few understand the urgency and ramifications. For lighter reading, I recommend journalist Elizabeth Kolbert’s book The 6th Extinction.
Cheers. And, please vote.
For a geological map of Minnesota: http://geo-site.net/mn/Maps_of_Isanti_County_files/small%20geology%20map%20minnesota_1.jpg
Life on Earth: https://phys.org/news/2015-10-life-earth-billion-years-agomuch.html
Life on Earth (more info): https://www.sciencedaily.com/relses/2015/10/151019154153.htm
6th Mass Extinction: https://www.sciencedaily.com/releases015/06/150619152142.htm
Biodiversity Loss: https://www.sciencedaily.com/releas/2018/09/180912133502.htm
Mass extinction definition: https://www.dictionary.com/browse/mass-extinction
Background extinction definition: https://www.dictionary.com/browse/background-extinction
Anonymous says
I LOVE Elizabeth Kolbert’s book. HIGHLY recommended!
Rick Dworsky says
In a society of specialization tasks are left to those with expertise, regardless of their ability, their authority, to impliment change. The rest of us go about our business as though we were protected by these woefully powerless ‘parents’ ~ testing our strength against them, rebelliously. We played Tinker Bell’s game of “I won’t grow up!” far too long, and it’s probably too late now to ever grow up, take responsibility, and fix things. Human extinction looms.