1. Biodiversity Chapter 27

2. Read about Easter Island (intro to Chapter 27)

3. To Review… Early life on earth was dominated by heterotrophic, prokaryotic organisms. Early life on earth was dominated by heterotrophic, prokaryotic organisms. The sun’s rays were a limiting factor to evolution away from water and toward eukaryotic life. The sun’s rays were a limiting factor to evolution away from water and toward eukaryotic life. Once free oxygen was available, a species explosion took place that led to millions of eukaryotic species (protists, fungi, plants and animals) Once free oxygen was available, a species explosion took place that led to millions of eukaryotic species (protists, fungi, plants and animals)

4. Extinctions Extinction- irrevocable loss of a species Extinction- irrevocable loss of a species Endangered species- any endemic species that is extremely vulnerable to extinction. Endangered species- any endemic species that is extremely vulnerable to extinction. Endemic- originating in one region and found nowhere else. Endemic- originating in one region and found nowhere else. Over 99% of all species that have ever lived (eukaryotic and prokaryotic) are now EXTINCT. Over 99% of all species that have ever lived (eukaryotic and prokaryotic) are now EXTINCT.

5. Mass Extinction Mass Extinction There have been at least five mass extinctions in the earth’s history. There have been at least five mass extinctions in the earth’s history. Mass extinction- catastrophic event or geologic period of time in which major groups of organisms are lost. Mass extinction- catastrophic event or geologic period of time in which major groups of organisms are lost.

6. Mass Extinctions 540 mya- 79% of all species lost due to possible glaciation 540 mya- 79% of all species lost due to possible glaciation 440 mya- At least 100 families of marine organisms lost 440 mya- At least 100 families of marine organisms lost 360 mya- 70% of marine organisms lost, including jawless fishes and placoderms 360 mya- 70% of marine organisms lost, including jawless fishes and placoderms 248 mya- HUGE extinction. 90-95% of all species lost due to possible asteroid impact 248 mya- HUGE extinction. 90-95% of all species lost due to possible asteroid impact 65 mya- dinosaurs totally disappear. 85% of all species lost 65 mya- dinosaurs totally disappear. 85% of all species lost Present- possible 6 th mass extinction currently in process due to cultural practices and population growth rates. Present- possible 6 th mass extinction currently in process due to cultural practices and population growth rates.

7. Why Extinction Happens Environmental changes are always the prompt for an extinction, although the cause of an extinction may be compex. Environmental changes are always the prompt for an extinction, although the cause of an extinction may be compex. –Habitat –Climate –Food –Increase in predators –Change in reproductive abilities –Etc…

8. Human Population Growth

11. Current Population Trends The current world’s population is over 6,800,000,000. The current world’s population is over 6,800,000,000. The current US population is over 308,000,000. The current US population is over 308,000,000. While the trend is still toward population growth, the trend worldwide is population growth decline. While the trend is still toward population growth, the trend worldwide is population growth decline.

12. Causes of Human Population Increase Agriculture (11,000 years ago) Agriculture (11,000 years ago) Industrial revolution (1800s) Industrial revolution (1800s) Mechanized agriculture Mechanized agriculture Advances in medicine and hygiene Advances in medicine and hygiene

13. Vocabulary Pollutant- natural or synthetic substance in an environment that there is no evolved mechanism for to prevent the substance from accumulating to harmful levels. Pollutant- natural or synthetic substance in an environment that there is no evolved mechanism for to prevent the substance from accumulating to harmful levels. Human Pollutants: Human Pollutants: Biodiversity- biological diversity in an environment as measured by the number of species and their relative abundance. Biodiversity- biological diversity in an environment as measured by the number of species and their relative abundance.

14. Resource Consumption Early human populations were negligible compared to what they are now. Early human populations were negligible compared to what they are now. What natural resources are you using today that early humans were not? What natural resources are you using today that early humans were not? How does human use of resources affect the biodiversity of the planet? How does human use of resources affect the biodiversity of the planet?

15. Rachel Carson Section 27.3 Section 27.3 Be familiar with Rachel Carson’s story. Be familiar with Rachel Carson’s story. What was her contribution to the environmental movement? What was her contribution to the environmental movement?

16. Threats to Biodiversity Endangered species- an endemic species that is extremely vulnerable to extinction. Endangered species- an endemic species that is extremely vulnerable to extinction. Endemic- originating in one region and not found anywhere else. Endemic- originating in one region and not found anywhere else.

17. Aleutian Islands Example Killer Whales Sea ottersHarbor Seals Steller Sea Lions Sea Urchins Kelp (habitat for fish) Ocean perch and herring (need kelp for habitat)

18. Causes and Effects of threats to Biodiversity Habitat Loss and Fragmentation Habitat Loss and Fragmentation Species Introductions Species Introductions Overharvesting Overharvesting Illegal Wildlife Trading Illegal Wildlife Trading

19. Habitat Loss and Fragmentation Habitat Loss- physical reduction in suitable places to live (because of pollution or loss of habitable space) Habitat Loss- physical reduction in suitable places to live (because of pollution or loss of habitable space) 90% of species that become extinct become extinct at least partly because of loss of habitat. 90% of species that become extinct become extinct at least partly because of loss of habitat. Almost all tall grass prairies, 50% of wetlands, and 95% of old-growth forests have disappeared in the US. Almost all tall grass prairies, 50% of wetlands, and 95% of old-growth forests have disappeared in the US.

20. Fragmentation Fragmentation is the division of a habit into smaller parts. The habitat is “patched” or cut into patches. Fragmentation is the division of a habit into smaller parts. The habitat is “patched” or cut into patches. Fragmentation of any habitat results in net habitat loss and puts more species on the periphery of the habitat. Fragmentation of any habitat results in net habitat loss and puts more species on the periphery of the habitat.

21. Hazards of living in a fragmented habitat Small population size Small population size Decreased resources Decreased resources Exposure to: Exposure to: –Wind –Fire –Temperature changes –Predators –Pathogens

22. Equilibrium Model of Island Biogeography Robert MacArthur and Edward O. Wilson Robert MacArthur and Edward O. Wilson 50% loss of a habitat will drive 10% of the species to EXTINCTION. 50% loss of a habitat will drive 10% of the species to EXTINCTION. 90% loss of a habitat will drive 50% of the species to extinction. 90% loss of a habitat will drive 50% of the species to extinction.

23. Indicator Species A species that, by its abundance or scarcity, is a measure of the health or degradation of a habitat. A species that, by its abundance or scarcity, is a measure of the health or degradation of a habitat. Birds!- live everywhere, react quickly to changes, easy to track. Birds!- live everywhere, react quickly to changes, easy to track. Polar Bears- mammals do not react as quickly to change and may have very low adaptive ability Polar Bears- mammals do not react as quickly to change and may have very low adaptive ability

24. Another Threat to Biodiversity- Species Introductions New species not naturally occuring in an area can threaten endemic ones. New species not naturally occuring in an area can threaten endemic ones. Low predation for introduced species Low predation for introduced species Water Hyacinth Japanese Beetle European starling

25. Invasive Species to the US SPECIESORIGIN MODE OF INTRODUCTION OUTCOME Water Hyacinth South America Intentional (1884) clogged waterways, other plants shaded out Dutch Elm Disease Asia/Europe Accidental (infected timber Millions of elms destroyed Zebra mussel Russia Accidental- ship Clogged pipes, displaced native bivalves Japanese Beetle Japan Accidental- on flowers 300 species defoliated Nutria South America Accidental release Crop damage, overgrazing of marsh habitat European starling Europe Intentional release Outcompeted native birds, crop damage, swine disease vector Sea lamprey North Atlantic Ship hulls Trout destroyed in Great Lakes

26. Another Threat to Biodiversity- Overharvesting Overharvesting occurs in commercially valuable species Overharvesting occurs in commercially valuable species Overharvesting of species can occur by harvesting too many of the species OR by harvesting too many young of the species. Overharvesting of species can occur by harvesting too many of the species OR by harvesting too many young of the species. Marine life (whales, sharks, etc.) are easily threatened by overharvesting. Marine life (whales, sharks, etc.) are easily threatened by overharvesting.

27. Another Threat to Biodiversity- Illegal Wildlife Trading The more rare a species is, the more valuable it is on the black market. The more rare a species is, the more valuable it is on the black market. Polar bears, grizzly bears, bald eagles, chimpazees, mountain gorillas, tiger and lion skins, rhinoceros horns, elephant tusks. Polar bears, grizzly bears, bald eagles, chimpazees, mountain gorillas, tiger and lion skins, rhinoceros horns, elephant tusks.

28. The Once and Future Reefs Coral Reef- hard formations consisting of acumulated remains of marine organisms. Coral Reef- hard formations consisting of acumulated remains of marine organisms. Develop in warm, clear waters. Develop in warm, clear waters. Hundreds of species make their homes in and around coral reefs. Hundreds of species make their homes in and around coral reefs.

29. Reef Development Dinoflagellates (photosynthetic) live as symbionts in tissues of reef building corals. Dinoflagellates (photosynthetic) live as symbionts in tissues of reef building corals. Contribute to oxygen in water, recycle mineral wastes, provide nutrition for the coral polyp. Contribute to oxygen in water, recycle mineral wastes, provide nutrition for the coral polyp. When stressed, coral polyps expel the algal symbionts. When stressed, coral polyps expel the algal symbionts. Within several months, the coral dies and only bleached, hard skeletons remain. Within several months, the coral dies and only bleached, hard skeletons remain.

30. Dangers to Reefs Temperature increases Temperature increases Oil spills Oil spills Sewage Sewage Dynamite fishing Dynamite fishing Anchor fishing Anchor fishing Cyanide fishing Cyanide fishing Selling of fishing rights Selling of fishing rights Biodiversity off the coast of Florida has been reduced by over 30% in the past 40 years! Biodiversity off the coast of Florida has been reduced by over 30% in the past 40 years!

31. Conservation Biology Conservation biology- a field of science that surveys biodiversity, interprets its ecological origins and identifies ways to maintain and use ecosystems in a way that might benefit humans. Conservation biology- a field of science that surveys biodiversity, interprets its ecological origins and identifies ways to maintain and use ecosystems in a way that might benefit humans. The goal of conservation is to conserve and utilize in sustainable ways, as much biodiversity as possible. The goal of conservation is to conserve and utilize in sustainable ways, as much biodiversity as possible.

32. Conservation Biology There are FAR more species in existence than we have identified. There are FAR more species in existence than we have identified. In a recent survey of Yellowstone Park, more archaeans were identified than all those that have been previously found. In a recent survey of Yellowstone Park, more archaeans were identified than all those that have been previously found. The smaller the organism is, the more likely it is that there are numerous species we haven’t identified yet. The smaller the organism is, the more likely it is that there are numerous species we haven’t identified yet.

33. As a rule of thumb: Countries that are monetarily wealthy have the least biodiversity and use the most natural resources. Countries that are monetarily wealthy have the least biodiversity and use the most natural resources. Countries that are the poorest monetarily have the most biodiversity and the fastest growing populations. Countries that are the poorest monetarily have the most biodiversity and the fastest growing populations.

34. Poverty as a risk to biodiversity People living in poverty often have to choose between saving themselves or saving an endangered species. People living in poverty often have to choose between saving themselves or saving an endangered species. Conservationists attempt to figure out ways for people to survive while protecting the environment. Conservationists attempt to figure out ways for people to survive while protecting the environment.

35. Solutions Ecotourism Ecotourism Strip Logging Strip Logging International cooperation International cooperation Managing cattle away from riparian zones Managing cattle away from riparian zones –Riparian zone- strip of vegetation along a stream or river that defends against flooding, drought and provides food, shelter and shade to wildlife.