I recently received a letter from a young reader from Oakville who asked the Conservation Department to bring back a now extinct species of parrot. "It would be an amazing sight to see these kings of color flocking in our forests," he wrote.
We can't help him. Extinction is death. The probability of an extinct species resettling the earth is so small as to be non-calculable, no matter how many zeros we place after the decimal point. Essentially, each species, including ours, has one-and only one- chance on this planet.
Is it any wonder that biologists treat extinction so seriously, and why they want to rescue animals and plants that are facing extinction.
Some extinction occurs naturally. As new species evolve and weather patterns change some species drop away, unable to compete in the changed environment. Scientists have calculated what they call a background or normal rate of one extinction per major group every million years.
Cataclysmic changes accelerate this rate of extinction. Life on earth has experienced at least five major mass extinctions that are believed to have been caused by terrific changes of climate brought about by upheavals of the earth's crust or by collisions with asteroids, comets or meteors. During those five major extinctions, anywhere from 60 to 95 percent of existing species disappeared within what has to be considered a snap of the finger in geological time. The last major extinction, often referred to as the K-T extinction, wiped out the dinosaurs, along with approximately 76 percent of all the species that occupied the planet.
According to the numbers, the planet is now experiencing another mass extinction, one which seems to be accelerating. For example, it has been roughly calculated that between 1600 and 1900, about 75 known species disappeared. Between 1900 and 1975, another 75 known species became extinct. That's a rate of one species every year, a much faster rate than has been calculated for some of the other major extinctions, and unknown losses would surely raise the rate much higher.
Humans are responsible for the current mass extinction. Our growing requirements for space and energy put pressure on other living things, and many species are succumbing. We change the world merely by living in it, and until that time when human population stabilizes we will almost certainly continue to diminish the biodiversity that we think is nature's ultimate goal or strategy.
In this special issue, we highlight some of the work that is going on to rescue species that are facing extinction as we celebrate the 25th anniversary of the Endangered Species Act.
Celebration seems out of place when we are talking about species disappearing from the earth at an unprecedented rate, but this special issue is to let you know about the good work being done on behalf of endangered species. We want to make you feel good about living in a state and a country where we have become aware of the necessity of doing all we can to rescue species from threats of extinction.
This awareness, politically and legally represented by the passage of our country's Endangered Species Act, is an important and necessary first movement toward conscious action to increase and maintain biological diversity.
Missouri is more fortunate than many other states in that we have the citizen support necessary to allow the Conservation Department to have a real impact in the drive to save endangered species. We have been able to acquire and preserve expanses of prairie, glade, riverine and big woods habitat crucial to the continued existence of many threatened species. We also have been able to guide landowners, developers and other state agencies toward land use practices that reduce the threats to endangered species.
Our team of animal and plant biologists are guided by the philosophy of biodiversity, believing that variety is as necessary to us environmentally as it is important to us personally and culturally. Not all states have such teams and such programs, just as all nations do not have an Endangered Species Act. So we really do have something to celebrate.