ENVS 1000U Lecture Notes - Lecture 9: Habitat Fragmentation, Ecotourism, Habitat Destruction
8 Feb 2016
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Document Summary
Biologists have described about 1. 8 million species. There may be as many as 100 million species. Biodiversity = the variety of all on earth (e. g. microbial, protists, plant, fungal and animal) Endemic species = species that are found in only one region of the world naturally and are at risk of going extinct. Endangered species = species that is in danger of becoming extinct throughout its range. Threatened species = species that are considered likely to become endangered in foreseeable future. Loss of species means the loss of genes and genetic diversity. Enormous genetic diversity of organisms on earth has potential for great human benefit (crops, fibers and medicines) Many pharmaceuticals contain substances originally derived from plants. Of top 150 drugs in u. s. , 118 based on natural sources: 74% on plants, 18% on fungi, 5% on bacteria, 3% on one vertebrate (snake) venom. 80% human population depends on traditional medicine; 85% of traditional medicine involves use of plant extracts.
