Which of the great extinctions happened the fastest?
In case you don't remember from grade school, the prehistoric extinctions took place between 438 and 65 million years ago. There were five major ones, named after the periods they ended: Ordovician, Devonian, Permian, Triassic, and Cretaceous. The Permian was the worst: 95% of all animal species were wiped out. But the Cretaceous (sometimes called the K-T) is the best known, since it is the one that killed off the dinosaurs.
Oh yes, there's one more. That's the one that is going on right now.
Did you raise your left eyebrow just now? Good. If not, keep reading—it gets better (or worse, depending on how much of this regrettably true story you believe).
The current extinction is just getting started, so it's still too early to tell how it will compare with earlier ones. But it has already claimed millions of species—most during the 20th century.
All of the prehistoric extinctions happened over periods of millions of years. In most cases, they were so gradual that no perceptible change would have been observed within the lifetime of any of the animals living at the time.
However, this one is happening at a rate that is hundreds of times faster. Nobody knows for sure, since we don't know how many species are being lost. For that matter, we don't even have a good idea of how many species there are (the number is at least 10 million).
But estimates can be made. This is usually accomplished by looking at the number of known species lost within one genus (species group). If we do this for several genera and extrapolate to all of them, we can make educated guesses about the current rate of extinction. The number is startling: every year at least 25,000 species are lost forever. The process will "hit bottom" in 200 to 400 years, with about 5 percent of all species remaining.
In North Carolina, 49 species are listed as endangered, according to the U.S. Fish and Wildlife Service. 23 of these are animals: two bats, one butterfly, three fish, five birds, four clams, four mammals, one snail, one spider, and one turtle. Notable entries include the bald eagle and the red wolf.
One species that has not yet made the list is Eurycea junaluska. This is a salamander that is native to Western North Carolina and East Tennessee. It is extremely rare: there are only seven known populations in existence. All of these are along the Cheoah River in the Nantahala National Forest. Meanwhile, timber harvesting continues in the area, and more is planned.
The Southern Appalachian Biodiversity Project (phone 258-2667) is fighting to save local endangered species. Their strategy is one of habitat protection: they are “working to preserve and restore native wildlands in the Southern Appalachian region”. Habitat loss is perhaps the gravest threat to regional biodiversity.
The requirement for an official list was mandated by the Endangered Species Act of 1973. The intent of this law was to perform a sort of biological triage: identify the wounded and get them to the hospital. It’s a good idea, at first glance. And many good things have come of it. However, more holistic thinking is needed.
All species are part of the web of life. Once it starts to unravel, it can come apart very quickly. Like a house of cards, the loss of one species can drastically affect the remaining ones. What’s needed is a way to protect them all, before they become endangered.
But you will not miss them until they are gone. How will you know? It will be a very personal, individual thing. For example:
You’re watching some old sitcom on TV. During an outdoor scene, you hear a familiar sound in the background. You recognize it as the song of a bird that used to visit your backyard. And you haven't heard it in a long time. Come to think of it, there haven’t been many birds back there for several years. You realize that you miss that sound, in a more profound way than you would ever have thought. What you wouldn't give to hear that bird—any bird—in your backyard again!