|MadSci Network: Zoology|
Maria, While it is extremely hard to determine which species will become extinct next, it is well known that many species become extinct each day from man's destruction of their habitat. San Diego county, where I live, is a hot spot in the world for threatened and endangered species because of rampant development here which destroys habit daily. Another point is that important species are not just "charismatic megafauna" - big cuddly animals. Many organisms important to proper functioning of our ecosystem are so small you would have trouble even seeing them. It may help you to read a note I wrote: EXTINCTION: CALIFORNIA'S GRIZZLY SYMBOL. Why do people say they LOVE our area? Is it our climate with its quiet, clean air? Rolling topography with its rich diversity of plants and animals and beautiful views? Most developers scrape the land bare and level it. This destroys habitat, views and with it plants and animals that have lived here as species far longer than humans. Habitat is all components of an area needed for something to live there. We need a reasonable goal for what we want our area [habitat] to be in the future. I propose Aldo Leopold's statement as a starting point "A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise." Although we are not endangered, many endangered species call this area home too. Congress recognized the importance to us of threatened and endangered species in 1973 when they enacted our Threatened and Endangered Species Act. Since the 1600s the rate of extinction has accelerated rapidly because of human population growth and resource consumption. Today, most of the world’s habitats are changing faster than most species can adapt to such changes. The current global extinction rate is estimated at about 20,000 species per year. The survival of ecosystems (plant and animal communities and their physical surroundings) such as brush or wetlands depends on their biodiversity, or variety of plants, animals, and habitats, as well as the many interactions among these species. The removal or disappearance of one or several species may irreversibly damage the ecosystem and lead to its decline. The irreversible loss of biodiversity has a serious impact on the ability of remaining species, including humans, to survive. Humans depend on species diversity and healthy ecosystems to provide food, clean air and water, and fertile soil. In addition, we benefit greatly from the many medicines and other products that biodiversity provides. As many as 40 percent of our modern pharmaceutical medicines are derived from plants or animals. A recent article in the North County Times "A fertile source for lifesaving drugs" describes one important resource, North County's wetlands. Dr William Fenical, director of the Scripps Center for Marine Biotechnology and Biomedicine is discovering microbes that have medicinal qualities in these fast-disappearing wetlands [we have less than 10% of the original wetlands left in San Diego County]. As species evolve, most adapt to a specific habitat or environment that best meets their survival needs. Without this habitat the species may not survive. Pollution, drainage of wetlands, conversion of shrub lands, urbanization, and road and dam construction have destroyed or seriously damaged and fragmented available habitats. Habitat fragmentation, the isolation and division of habitats into smaller areas, has caused plant and animal species in the remaining islands of habitat to lose contact with other populations of their own kind. This reduces their genetic diversity and makes them less adaptable to environmental or climatic change. These small populations are highly vulnerable to extinction. Kelleen Flaherty, Biology expert says: Extinction is a critically important topic in biology that needs far more attention than it is getting. No one knows precisely how many species are going extinct. The fact that no one knows makes the whole idea of extinction even scarier. As a result of the activity of human beings (pollution and destruction of the environment), lots of species are going extinct before we even get a chance to identify them! Aldo Leopold said "If the biota in the course of aeons has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering".Wallace Stegner said "We are the most dangerous species of life on the planet, and every other species, even the earth itself, has cause to fear our power to exterminate. But we are also the only species which, when it chooses to do so, will go to great effort to save what it might destroy." Habitat destruction has made San Diego County a hot spot in the world for threatened and endangered species. In 1998 San Diego City approved a Multiple Species Habitat Conservation Plan that was hailed as an important step in preserving ALL species, especially those threatened with extinction by man The last California Grizzly in San Diego County was shot in 1909 and the last one in California killed in the 1920's!
Try the links in the MadSci Library for more information on Zoology.