Conservation and Biodiversity

1. Conservation and Biodiversity

2. Over 90% of all species that have ever existed have disappeared from natural selection

3. Current rate of extinction • The current rate of extinction exceeds the natural background rate of extinction • The extinction rate is caused by one sole species: Humans

4. Biodiversity The totality of genes, species, and ecosystems of a region The variability amongst living organisms from all sources, including terrestrial, marine and other aquatic ecosystems and ecological complexes of which they are a part.

5. Genetic Diversity • A level of biodiversity that refers to the total number of genetic characteristics in the genetic makeup of a species.

6. Genetic diversity • A healthy population usually contains a good deal of genetic diversity, individuals varying considerably. • This variability provides the basis for natural selection and evolution. • A species that has been brought close to extinction, and then recovered contains less genetic diversity and thus displays less variability: a small population can contain fewer genes in total than a large one.

7. Seals example • Some species of seals that were reduced to a tiny population in the nineteenth century by hunting, have, in recent decades, with the removal of hunting pressure, increased in numbers. But the "new" population is genetically impoverished and displays less variability than the original one.

8. Species Diversity • Species diversity the number of species in an area and their relative abundance

9. Habitat Diversity • The diversity of a place at the level of ecosystems. • The variety of habitats within an area. • These are sometimes called microhabitats.

10. Natural selection • Speciation occurs as a result of the isolation (geographical or reproductive) of populations. • Diversity exists within the population randomly • If the trait helps the individual survive, it is passed onto the offspring.

11. Survival of the fittest • Organisms possessing such advantageous characteristics increased the proportion of beneficial characteristics in the population • Pressure from the environment influences the proportion of a population displaying a characteristic: in this way organisms become adapted to their environment and way of life.

12. Evolution of a new species • If a small population is isolated on a remote island, desert oasis, or mountain peak, a new species may evolve quite quickly through the combined effects of the smallness of the gene pool, the near impossibility of genetic material coming in from elsewhere, and adaptation to a specialised environment.

13. Isolation can lead to different species • Species: A population of organisms that can breed and produce fertile offspring • Isolation of populations can lead to different species being produced that are unable to interbreed to yield fertile offspring.

14. Geographic Isolation • The small mammals (from example the voles) of some of the islands off the coast of Scotland have been separated from the populations on the mainland for just a few thousand years - since the rise in sea level following the Ice Age

15. Behavioural Isolation • If the differences that prevent reproduction and the inability to produce fertile offspring, this will cause new species to be produced.

16. Isolation of species • In Lake Victoria there are 170 species of cichlids (99% endemic); in Lake Tanganika 126 species (100% endemic); in Lake Malawi 200 species (99% endemic). These lake faunas have, probably been isolated from each other for millions of years, but differences in isolated populations can develop quite quickly.

17. Islands • Oceanic island ecosystems show a high level of endemism. • Endemic = exclusively native to a place or biota • For example: the Hawaiian Islands and the Galapagos are centres of considerable biodiversity, and both archipelagoes have many species, and indeed some families, not found elsewhere.

18. Plate tectonics • Plate activity in generates new and diverse habitats, thus promoting biodiversity. • Gene pools are isolated by moving plates. Natural selection over time creates new species

19. Ecosystem stability and diversity Greater habitat diversity leads to greater species and genetic diversity A complex ecosystem, with its variety of nutrient and energy pathways, provides stability An ecosystem’s capacity to survive change may depend on diversity, resilience and inertia.

20. Simplification of ecosystems • Human activities often simplify ecosystems, rendering them unstable, for example, North America wheat farming versus tall grass prairie

21. Changes in diversity with succession • The pioneer community is less diverse than the climax community • human activities modify succession, for example, logging, grazing, burning

22. Factors that lead to loss of diversity. natural hazard events (for example, volcanoes, drought, ice age, meteor impact) habitat degradation, fragmentation and loss agricultural practices (for example, monoculture, use of pesticides, use of genetically modified species) introduction and/or escape of non-native species Pollution hunting, collecting and harvesting.

23. Extinctions from humans may be greater than any in the past

26. habitat degradation and fragmentation

27. Fragmentation The breaking up of large natural places into smaller fragments or islands of habitat.

28. Around half of the world’s forest are gone. The rate of loss is 10 times higher than the rate of growth

30. Invasive Species: They compete with native species for resources and foodThey prey on native speciesThey can damage local crops, people's homes and even cause diseases.

31. pollution • Industrial air pollution from the developed world is carried on the dominant wind currents up to the arctic. • After settling onto the tundra, snow and ice it is absorbed into the food chain.

32. Chemical pollutants have been responsible for affecting the reproductive organs of fish, alligators and polar bears, preventing them from producing babies. • Chemical pollution in the environment also affects humans - 46 US states have issued warnings against eating local fish because of dioxin contamination, and in Europe, human breast milk passes on more dioxin to our babies than is legally allowed for cow's milk. • Despite this, the amount of pesticide sprayed on our crops around the world has increased 26 times in the last 50 years.

33. Climate change

34. The vulnerability of tropical rainforests and their relative value in contributing to global biodiversity. Tropical rain forests contains the largest biodiversity of the world’s biomes

35. Estimates of numbers of species and past and present rates of species extinction. • population size • reduction in population size • numbers of mature individuals • geographic range and degree of fragmentation • quality of habitat • area of occupancy • probability of extinction.

37. Pressures on organisms and habitats • Ecological pressures: Habitat to live, predator – prey relationships • Economic pressures: Resources are exploited for economic reasons

38. Vulnerable to extinction

39. Human impact • One third of the world's resources have been used up in the last 30 years. • One calculation estimates that in 50 years' time, we will need another planet Earth to sustain the world's population if it keeps using resources the way it does today. • We simply catch too many fish, use too much wood and waste too much fresh water.

40. State the arguments for preserving species and habitats. • ethical • aesthetic • genetic resource • commercial (including opportunity cost) • life-support • ecosystem-support functions

41. Values • It is argued that for many parts of the world, very little is known about the biodiversity. • In Africa, parts of Asia, South America and Australasia there almost certainly exist hundreds of thousands of species, particularly of the less conspicuous groups (mosses, liverworts, algae, fungi, bacteria, molluscs, insects and other invertebrates) that are unknown. • It would be a tragedy, it is maintained, if these were eliminated through habitat destruction (e.g. forest clearance, wetland drainage) before being documented.

42. Yet to be discovered.. • Even less is known of the biochemical and other properties of many of the species of plants and animals that make up the earth's biological resources. Almost certainly many species of plant, animals and microorganism, not now known to be of use, will be found to be of immense value as sources of food, medicines or natural pesticides.

43. Medicines from plants • The first antibiotics (such as penicillin) were obtained from fungi. • A rare species of yew (Taxus) from the Pacific Northwest of the USA has recently been found to produce a chemical that may prove of value in the treatment of certain forms of cancer. • A whole series of plants long used by the Australian Aboriginals as sources of healing materials, or as foodstuffs, are now being scientifically evaluated.

44. More medicines from plants • Pyrethrins are natural insecticides (although they are now also synthesised) occurring in the flowers of Chrysanthemum species. These natural compounds have many advantages over certain entirely artificial insecticides. • The biological resources of the world's rainforests or scrublands may yield yet another penicillin or pyrethrin. • The rosy periwinkle, from the Madagascan forest is curing children with leukaemia as two drugs from the plant give over an 80% remission rate.

45. Ecological support • Natural ecosystems are made up of many species of organism, linked to one another in a myriad of intricate ways. Some scientists argue that complex systems are inherently stable than those that are simple. • If one energy pathway or feedback loop is damaged or removed, others exist that can take over. Although this is not universally accepted, the idea is frequently advanced that the preservation of as many species as possible, and as, natural or semi-natural habitat as possible, may render the environment (both on the scale and that of the whole biosphere) more stable, and less likely to be affected by the spread of disease (plant, animal or human) or some other environmental catastrophe. • The removal of the natural, multi-layered, varied forest from tropical islands, and the establishment of single-species coconut plantations, were followed by serious damage when the when the islands were affected by tropical storms. • Those islets that still supported their mantle of natural vegetation were much less affected and indeed experienced build-up rather than erosion.

46. Genetic diversity • Loss of species depletes the gene base of many crops and farm animals. • We rely on a few crop plants in monoculture for our food and pests and diseases can wipe out non-resistant strains. • Breeders are only one-step ahead of the diseases and require wild strains from which they may find resistant genes.

47. Genetic diversity example • Wheat rice and maize provide one half of the world's food. • In the 1960s, wheat stripe rust disease wiped out a third of the yield in the US. • It was the introduction of resistant genes from a wild strain of wheat in Turkey that saved the crops.

48. Ethics • There is a moral duty upon humanity to preserve as much as possible of the world's biodiversity. • This argument states that plants and animals are complex beings, interesting and often beautiful.

49. the Convention on International Trade in Endangered Species (CITES)

50. Bibliography • State of the Planet http://www.bbc.co.uk/nature/programmes/tv/state_planet/habitat.shtml • IB Booklet Biodiversity and Conservation