Biodiversity

1. Biodiversity Variety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life.

2. Hot Spots • A hotspot is an area where there are many threatened and endangered species • There are currently 34hotspots in the world today

3. Species Diversity • Number and abundance of species present in different communities

4. Ecological Diversity • The variety of terrestrial and aquatic ecosystems found in an area or on the earth

5. Functional Diversity • The biological and chemical processes such as energy flow and matter recycling needed for the survival of species, communities and ecosystems • Food Chains & webs

6. Genetic Diversity • The variety of genetic material within a species or a population

7. Theory of Natural Selection • Explains how life has evolved from a common ancestor

8. Survival of the fittest • Organisms suited for the environment will survive to reproduce, thus passing down desirable traits. • Examples: • Giraffes • Camels • Influenza virus • Venus fly trap • NOTE – fittest does not equal strongest!!!

9. Natural Selection and Geological Processes • Location on the earth influences biodiversity (rainforest vs. tundra) • Continental movement • Earthquakes and volcanoes • Climate change • Cyclic cooling and heating of the earth • Catastrophic events • Asteroid impacts, major volcanic eruptions

10. Continental movement • Theory of Continental Drift • The earth has large plates located between the lithosphere and asthenosphere • These plates move very slowly (1-3cm/yr) • This creates oceans, mountain ranges, volcanoes, earthquakes, trenches

11. 225 million years ago 225 million years ago 135 million years ago 65 million years ago Present Fig. 4-5, p. 88

12. Continental Movement

13. Climate Change

14. Climate Change and Natural Selection • Changes in climate throughout the earth’s history have shifted where plants and animals can live. Figure 4-6

15. Catastrophic events • Asteroid impacts • Super Volcanoes • These affect biodiversity locally and on a world-wide scale

16. Speciation - formation of a new species • Two Phases • 1. Geographic isolation • A population is removed from others of it’s species for a long period of time • 2. Reproductive isolation • The removed population becomes so genetically different over time that it can no longer interbreed with others of it’s species

17. Measurements of Biodiversity • Species diversity – the number of different species in a community • Species evenness – the abundance of species in a community

18. Richness and Sustainability • Higher species richness = higher productivity = higher sustainability • Reasons: • More likely to withstand droughts, disease, climate change, nutrient shortages • Higher number of producers lead to a higher biomass which leads to more carbon and nitrogen cycling

19. Extinction – the loss of a species • Background extinction – low rate of extinctions • Mass extinction-high rate of extinctions due to specific cause • Climate change

20. Three types of extinctions • Local: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. • Ecological: Occurs when so few members of a species are left they no longer play its ecological role. • Global (biological): Species is no longer found on the earth.

21. Global Extinction • Some animals have become prematurely extinct because of human activities. Figure 11-2

22. Steps to extinction Background extinctions: • Rare • Threatened • Endangered • Extinct

23. Endangered and Threatened Species: Ecological Smoke Alarms • Endangered species: so few individual survivors that it could soon become extinct. • Threatened species: still abundant in its natural range but is likely to become endangered in the near future. Figure 11-3

24. Red lists • ICUN – International Union for the Conservation of Nature and Natural Resources • Published list of threatened species • www. iucnredlist.org

25. Some species are more prone to extinction: • K-strategists • Specialists • Tertiary consumers • Fixed migratory patterns • Narrow distribution • Commercially valuable • Large territories

26. Florida manatee Kirkland’s warbler Grizzly bear Knowlton cactus African elephant Swallowtail butterfly Humpback chub Utah prairie dog Siberian tiger Golden lion tamarin Fig. 11-3, p. 224

27. Giant panda Blue whale Whooping crane Northern spotted owl Black-footed ferret Mountain gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros Fig. 11-3, p. 224

28. Indian Tiger Range 100 years ago Range today (about 2,300 left) Fig. 11-8a, p. 230

29. Black Rhino Range in 1700 Range today (about 3,600 left) Fig. 11-8b, p. 230

30. African Elephant Probable range 1600 Range today Fig. 11-8c, p. 230

31. Asian or Indian Elephant Former range Range today (34,000–54,000 left) Fig. 11-8d, p. 230

32. Extinction Rate • The percentage of species that go extinct within a certain time period • The current extinction rate is increasing at an alarming rate due to human activities

33. Endangered Species History of Extinctions • Extinctions have existed long before humans had an influence • The current extinction crisis is the first to be caused by a single species- US! . This is happening faster than ever; a few decades versus thousands to millions of years. • Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest

34. Effects of Humans on Biodiversity • The scientific consensus is that human activities are decreasing the earth’s biodiversity. Figure 4-13

35. Human Caused Extinction • Causes include: • HIPPO C • Habitat Destruction • Invasive species • Population Growth • Pollution • Over-harvesting • Climate Change

36. Species and families experiencing mass extinction Bar width represents relative number of living species Millions of years ago Era Period Extinction Current extinction crisis caused by human activities. Many species are expected to become extinct within the next 50–100 years. Quaternary Today Cenozoic Tertiary Extinction 65 Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including many foraminiferans and mollusks. Cretaceous Mesozoic Jurassic Extinction Triassic: 35% of animal families, including many reptiles and marine mollusks. 180 Triassic Extinction Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites. 250 Permian Carboniferous Extinction 345 Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites. Devonian Paleozoic Silurian Ordovician Extinction 500 Ordovician: 50% of animal families, including many trilobites. Cambrian Fig. 4-12, p. 93

37. Natural Extinctions • Causes include • Climate change • Change in ecosystem • Lack of adaptations to change

38. How do extinctions affect us? • Use value lost – medicinal use, recreation, crops, lumber • Economic value – ecotourism (African safari) • Genetic information – genetic diversity lost • Non-use values – appreciation

39. Case Study: The U.S. Endangered Species Act • Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S. Figure 11-18