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Title: Biodiversity: Preserving Species
Copyright © McGraw-Hill Education.
Page 2: Biodiversity of the Species Concept
Biodiversity Definition: Variety of life in the world or a particular habitat.
Genetic Diversity: Variety of different versions of the same genes within a species.
Species Diversity: Number of different kinds of organisms within a community.
Ecological Diversity: Richness and complexity of a community.
Page 3: Species Diversity
Species Richness: Total number of different species in a community.
Species Evenness: Relative abundance of individuals within each species.
Reference: FIGURE 11.2.
Page 4: What Are Species?
Species Definitions:
Reproductive Isolation: Organisms that breed in nature and produce fertile offspring.
Phylogenetic Species Concept: Focus on the branches in a taxonomic tree, emphasizing cladistic relationships.
Evolutionary Species Concept: Defines species in evolutionary and historical terms.
Page 5: Molecular Techniques
DNA Sequencing: Provides insight into taxonomic and evolutionary relationships.
Genome: Total DNA sequence that characterizes a species.
Use of biological samples (blood, fur, feces) for species classification or identification.
Page 6: How Many Species Are There?
Currently Identified Species: 1.7 million.
Estimates of Total Species: Range from 3 to 50 million, with recent data suggesting 4 to 6 million insect species.
Invertebrates account for 65% of known species; many undiscovered.
Biodiversity Hotspots: Tropical rainforests and coral reefs are critical areas.
34 hotspots (1.4% of world’s land area) contain 75% of the world's threatened mammals, birds, and amphibians.
Page 7: Known vs. Threatened Species
Current Estimates:
Mammals: 5,515 known, 1,197 endangered (21.7%).
Birds: 10,424 known, 1,375 endangered (13.2%).
Reptiles: 10,272 known, 944 endangered (9.2%).
Amphibians: 7,448 known, 2,271 endangered (30.5%).
Fishes: 33,200 known, 1,275 endangered (3.8%).
Insects: 1,000,000 known, 1,046 endangered (0.01%).
Molluscs: 85,000 known, 1,950 endangered (2.3%).
Other groups with various known and threatened figures.
Total of 1,729,374 known species and 23,530 threatened.
Source: IUCN Red List, 2015.
Page 8: Biodiversity Hotspots
Hotspot Regions:
Caucasus, California Floristic Province, Mediterranean Basin.
South-Central Indo-Burma, China Mountains, Polynesia and Caribbean Islands.
Various other regions listed with their unique biodiversity stats.
Page 9: Benefits of Biodiversity
Food: Wild plants can provide genetic diversity and new food sources.
Drugs and Medicines: Over half of modern drugs derive from natural products. Pharmaceutical companies explore tropical regions, leading to issues with biopiracy. Sharing profits can incentivize preservation.
Page 10: Rosy Periwinkle
Significant for its anti-cancer drugs produced from this plant.
Page 11: Ecological Benefits of Biodiversity
Critical Functions: Soil formation, waste disposal, purification, nutrient cycling, and biogeochemical cycles depend on biodiversity.
Loss of even minor species can have severe consequences.
Total value of ecological services: $33 trillion/year, nearby half of total global GNP.
Page 12: Aesthetic and Cultural Benefits
Recreation activities (hunting, fishing, camping) generate significant economic impacts.
Americans spend $730 billion on nature-based recreation.
Ecotourism represents a sustainable economic model.
Existence Value: Organisms hold intrinsic value beyond their perceived utility.
Page 13: Threats to Biodiversity
Extinction: Complete species loss on Earth.
Natural Extinction: Background rate of one species per decade in undisturbed ecosystems.
Over 99% of all species that ever existed are now extinct.
Mass Extinctions: Major historical events that led to large species losses, including the Permian and Cretaceous extinctions.
Page 14: Major Mass Extinctions
Extinction events listed with causes such as climate change and meteorite impacts.
Visual representation in FIGURE 11.8 showing timeline of major extinctions.
Page 15: Accelerating Extinction Rates
Human impact may be increasing extinction rates by 100 to 1000 times the natural rate.
Historical 2-3 species lost per decade from 1600-1850; current projections could see half of all primates and a quarter of all bird species extinct within 50 years.
Comparable to past mass extinction events (e.g., Cretaceous period).
Page 16: Human-Caused Reductions in Biodiversity (HIPPO)
HIPPO: Acronym for key threats: Habitat destruction, invasive species, pollution, population growth, and overharvesting.
Habitat Destruction: Leading cause of extinction; includes loss from conversion of land for agriculture and urban development, mining, and destructive fishing.
Page 17: Invasive Species
Non-native species introduced (accidentally or intentionally) thrive without natural checks.
Approximately 50,000 non-native species have been established in the U.S. in the last 300 years, with a significant percentage causing problems.
Page 18: North American Invasive Species
Round goby, kudzu vine, zebra mussel, and more listed as problematic invasive species.
Page 19: Additional Human-Caused Reductions
Pollution: Concerns about pesticides and lead.
Population Growth: Increased human population pressures biodiversity.
Overharvesting: Examples like the passenger pigeon and overfishing of stocks.
Page 20: Commercial Use and Wildlife Smuggling
Profitability of wildlife smuggling with high value placed on animal parts and live specimens.
Statistics regarding the sale and death rates of wildlife involved in trade.
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Page 22: Endangered Species Act (ESA)
Established in 1973.
Definitions:
Endangered: In imminent danger of extinction.
Threatened: Likely to become endangered in the near future.
Vulnerable: Naturally rare or locally depleted.
Page 23: ESA Regulations
ESA regulates various activities involving endangered species:
Taking, selling, possessing, and transporting endangered species.
Protections extend to entire organisms and their parts.
Page 24: Current Status of ESA
1,372 species on the U.S. Endangered and Threatened lists, with about 386 candidates awaiting review.
Disparities in listed species, with many invertebrates unrepresented.
Slow listing process, causing species extinction before protection.
Page 25: Recovery Plans
Focus on specific types of species:
Keystone Species: Major community impact (e.g., bison).
Indicator Species: Linked to specific habitats (e.g., brook trout).
Umbrella Species: Need large areas of undisturbed habitat (e.g., northern spotted owl).
Flagship Species: Charismatic species appealing to the public (e.g., giant panda).
Notable successes in recovery like the bald eagle and whooping crane.
Page 26: Private Land and Critical Habitat
80% of habitats for many listed species are on private property.
Supreme Court rulings treat destruction of habitat as equivalent to "taking".
Habitat Conservation Plans (HCP) allow landowners to manage resources while benefiting endangered species.
Page 27: Controversy Surrounding ESA
Officially expired in 1992; viewed critically by various stakeholders.
Opposition from farmers and industry; some conservationists advocate for broader ecosystem preservation instead of focusing on individual species.
Page 28: International Wildlife Treaties
CITES: Established in 1975 to regulate trade in endangered species.
Currently lists 700 species threatened by international trade.
Page 29: Captive Breeding Programs
Breeding in zoos and gardens as a method for saving threatened species.
Zoos serve as genetic diversity repositories and provide animals for reintroduction.
Page 30: NeNe (Hawaiian Goose)
Successfully bred in captivity; numbers now over 500 after near extinction in the 1950s due to habitat loss.
Page 31: White Rhino
Remnant herd in 1895, now exceeding 17,500 individuals in protected areas.
Page 32: Issues in Captive Breeding
Limited space in zoos raises concerns over which species to save and genetic diversity.
Risks of inbreeding and habitat loss pose challenges.
Alternative approaches include funding anti-poaching efforts and habitat protection.