Suchergebnisse

Crops are being genetically engineered to produce a wide variety of drugs, vaccines and other pharmaceutical proteins. Although these crops may open the door to less expensive and more-readily available drugs, there is concern regarding the potential for contamination of human food and livestock feed, as well as environmental harm. The outlook for the production of pharmaceutical crops in California currently appears mixed. To date, 18 federal permits for field trials involving pharmaceutical or industrial proteins have been approved in California. However, the state's farming community and general public have thus far rejected pharmaceutical crop production, and a handful of local governments have recently banned the cultivation of genetically modified crops, including pharmaceutical crops. In light of the many pros and cons, three major approaches — the precautionary approach, risk analysis and cost-benefit analysis — could be used to move the debate about pharmaceutical crops forward.

Now is the time for conservation science—a mission-oriented scientific enterprise that seeks to protect nature, including Earth's animals, plants, and ecosystems, in the face of unprecedented human demands upon the planet. Conservation scientists apply principles from ecology, population genetics, economics, political science, and other natural and social sciences to manage and preserve nature. The focus of this textbook is first and foremost on protecting nature and especially Earth's biota. It also contains a heavy emphasis on highlighting strategies to better connect the practice of conservation with the needs and priorities of a growing human population. Now used at over 150 colleges and universities, Conservation Science is an original and modern approach to conservation. Gretchen Daily (Stanford University) says it well: "Based on unparalleled, firsthand experience, Kareiva and Marvier explore the innovative approaches to conservation being honed around the world today. Their account is rigorous and engaging, with fresh questions, data, and quantitative analysis interwoven with vivid stories of actual conservation practice in the field." Conservation Science was primarily written primarily for undergraduates and beginning graduate students who are interested either in academic careers or working in conservation at government agencies, non-governmental organizations, or international institutions. ; https://scholarcommons.scu.edu/faculty_books/1032/thumbnail.jpg

Species invasions are extremely common and are vastly outpacing the ability of resource agencies to address each invasion, one species at a time. Management actions that target the whole landscape or ecosystem may provide more cost‐effective protection against the establishment of invasive species than a species‐by‐species approach. To explore what ecosystem‐level actions might effectively reduce invasions, we developed a multispecies, multihabitat metapopulation model. We assume that species that successfully establish themselves outside their native range tend to be habitat generalists and that a tradeoff exists between competitive ability and habitat breadth, such that habitat specialists are competitively superior to habitat generalists. In this model, habitat destruction, fragmentation, and short‐term disturbances all favor invasion by habitat generalists, despite the inferior competitive abilities of generalist species. Our model results illustrate that providing relatively undisturbed habitat and preventing further habitat degradation and fragmentation can provide a highly cost‐effective defense against invasive species.