Species have been disappearing into extinction since they first existed on this planet, but the last 100 years have seen the rate of extinction leap alarmingly. At the time of the dinosaurs it is estimated that one species became extinct every 1,000 years, while today we lose one every day. The predictions are dismal: Within 30 years we will have lost 15 to 20 percent of all forms of life. Extinction should worry us for both practical and philosophical reasons.

More than 50 percent of our pharmaceuticals come from various species. Until the bark of Pacific yew was discovered to contain a cure for ovarian cancer, it was considered a worthless scrub tree, and was almost wiped out. We do not know what other precious essences are yet to be discovered in the multitude of species now existing, but scientists are sure that by ruining their habitats, we are cheating ourselves and our descendants of their benefits. In fact, it seems likely that the more exotically diverse habitats, such as those in the rain forests, are likely to yield, if gradually, substances of highest priority for human well being.

The federal Endangered Species Act (ESA) went into effect in 1973. Of the 1,304 U.S.

species that have been listed for protection since the law was passed, 12 were recovered by 2005, including the American bald eagle. Of the more than 568 animal species on the list in 2005, approximately 39 percent are either stable or improving. Still, there have been sporadic efforts to repeal the law.

Internet Assignment What is the current status of the Endangered Species Act?