466 Natural Resources Systems Copyright Goodheart-Willcox Co., Inc. The US Federal Lists of Endangered Species The US Fish & Wildlife Service also publishes Federal Lists of Endangered Species that identify species as either endangered or threatened. According to the USFWS, a species identifi ed as endangered is one that is in danger of extinction throughout all or a signifi cant portion of its range. If a species is listed as threatened, it is one that is likely to become endangered in the fore- seeable future throughout all or a signifi cant portion of its range. A species must be added to the federal lists of threatened and endangered wildlife and plants before it can receive protection by the Endangered Species Act (ESA), Figure 19-3. Species Criteria A species is added to the list when it is determined to be an endangered or threatened species because of the following factors: • The present or threatened destruction, modifi cation, or curtailment of its habitat or range • Overuse for commercial, recreational, scientifi c, or educational purposes • Disease or predation • The inadequacy of existing regulatory mechanisms • Other natural or manmade factors affecting its survival Should our national government spend resources to save native plant species? Explain your answer. Thinking Critically Paleobiologist Paleontology is the scientific study of the life of past geological periods as learned from studying fossil remains. Paleobiology is a branch of paleontology in which the biology of fossil organisms is examined. It is a combination of life science biology using the methods of Earth science paleontology. A paleobiologist uses field research of current plants and animals, as well as that of fossilized remains to learn about evolution. Paleobiologists are studying evolution on a molecular level and have successfully extracted DNA and RNA samples of ancient plants and animals. Paleobiologists must be willing to travel and spend months working wherever fossils or other Career Connection resources are found. As with most biologists’ work, paleobiologists also perform lab research. They may teach in universities, gather grant funding, and contribute to professional journals. They need to be willing to work in all settings and must also be self- starters to continue to gain funding for future work. Education required: A bachelor’s degree in biology is a great beginning, but to be successful in this career field, a PhD is required. It is suggested to study geology, Earth science, archeology, microbiology, paleontology, or paleobiology or a combination of these sciences to prepare for this career.