Presentation on theme: "Biodiversity and Conservation"— Presentation transcript:
1 Biodiversity and Conservation Chapter 21.1Biodiversity and Conservation
2 Biodiversity~2million different species have been identified and namedBiologists theorize that there may be hundreds of millions of species left to identifySpecies are grouped into 5 (sometimes 6) large categories called kingdoms
3 Kingdom ProkaryotaMany biologists split this kingdom into two: the Archaea and the Bacteria (they look similar but have different biochemistry properties)Characteristic features of prokaryotesCells with no nucleusDNA exists as circular chromosomeSmaller circles of DNA called plasmids are often presentNo membrane bound organellesOnly 70S ribosomes presentCell wall consisting of peptidoglycansUsually exist as single cells or small groups of cells
4 Kingdom ProtoctistaMade up of very diverse range of organisms that don’t really fit into other kingdoms(Kind of like the random bin of organisms)
5 Kingdom protoctista The characteristic features of protoctists: EukaryoticMostly single celled or exists as groups of similar cellsSome have animal-like cells (no cell wall) and are sometimes known as protozoaOthers have plant-like cells (with cellulose cell walls and chloroplasts) and are sometimes known as algae
6 Kingdom Fungi Characteristic features of fungi are: Eukaryotic Do not have chlorophyll and do not photosynthesize- they feed heterotrophicallySimple body form: may be unicellular or made up of long threads called hyphae (with or without cross walls) large fungi such as mushroom also have a compact mass of cells as part of their life cycleReproduce by sporesCells have cell walls made of chitin (not cellulose)Never have cilia or flagella
7 Kingdom Plantae Characteristics of plants are: Multicellular eukaryotes with cells that are differentiated to form tissuesSome cells have chloroplasts and photosynthesizeCell walls are always present and made of celluloseCells may occasionally have flagella, for example male gametes in mosses
8 Kingdom AnimaliaMulticellular eukaryotes with cells that are differentiated to form tissuesDo not have chloroplasts and feed heterotrophicallyDo not have cell wallsCells sometimes have cilia or flagella
9 Maintaining biodiversity Biodiversity can be defined as the degree of variation of life forms in an ecosystemUsually taken to include diversity at 3 levels:The number & complexity of communities in the ecosystemThe number of diff. species in the ecosystemThe genetic diversity of all the species in the ecosystem
10 Maintaining biodiversity Biodiversity is essential to maintain ecological stabilityThe measure and extent of biodiversity can be regarded as a measure of the ‘health’ of an ecosystemHigh biodiversity= healthyLow biodiversity- sick
11 Maintaining biodiversity As our human population expands and use more and more resources from diff. environments, biodiversity is being threatenedSpecies are being alarming rateConservation involves attempting to slow down, stop, or reverse the loss of biodiversity
12 Maintaining biodiversity The loss of biodiversity also presents an ethical dilemma: We share our planet with a huge range of other organisms and we have no right to make them extinct
13 Maintaining biodiversity Biodiversity within an ecosystem helps to maintain stabilityAll of the organisms in an ecosystem interact in many different ways, and if one species disappears, it can have ripple effects throughout the entire community
14 Maintaining biodiversity There are also direct benefits to human to maintain biodiversityAround 7000 drugs that are prescribed the doctors are derived from plantsAlmost 70% of these plants grow in tropical rain forestsThere are doubtless many more possible pharmaceuticals that we do not know about, but if we allow tropical rain forests to disappear, then we are losing potentially life saving drugs
15 Maintaining biodiversity The drugs vincristine and vinblastine (used to treat cancers of white blood cells) are derived from the Madagascan periwinkle.Madagascan periwinkle is endangered in the wild due to slash and burn agricultureFortunately, THE plant is being cultivated in many different countries
16 Maintaining biodiversity Also, we could use wild plant or animal species to introduce new and useful alleles into our crop plants and farmed animalsEx: species of rice Oryza longistaminata , which grows wild in Mali, is not suitable for cultivation as a crop plants b/c of its low yield and poor taste. However, it is resistance to a large number of strains of bacterial blight. It has successfully been interbred with cultivated rice to give varieties of rice that are resistant to the disease
17 Do Now 2.251.) List the main differences between a prokaryotic cell and a eukaryotic cell. Which kingdoms are prokaryotic? Eukaryotic?2.) Which kingdoms contain heterotrophic organisms?
18 Endangered speciesThe International Union for Conservation of Nature (IUCN) annually publishes a Red List of threatened species2011 list contained 16,119 speciesSpecies in the Red List are all under threat of extinction- disappearing forever from the Earth.
19 Endangered speciesMass extinction events in which millions of species become extinct at once have occurred several time throughout Earth’s history, but all have been due to natural events caused by sudden and huge changes in the environmentEx: asteroid colliding with planet
20 Endangered speciesCurrently facing likelihood of another mass extinction event due to habitat lossEx: draining wetlands, deforestation, slash and burn agriculture, and pollution of air and waterAlso, some species are becoming extinct due to over harvesting (hunting, fishing, etc…)
21 Endangered speciesHigh profile animals on the Red List: pandas, tigers rhinosEx: World Wide Fund for Nature (WWF) based 2011 Holiday advertisement around its Adopt-A-Tiger campaignLess inclusion of invertebrates, protists
22 Endangered species2011 estimates suggest that the global population of all tiger species is about 5000.In India, the pressure on the remaining tiger population is intense due to a rapidly expanding populationIn China, tiger products are valued as a cure to a variety of illness, so organized poaching is common
23 SAQ 21.5Suggest why the Red List contains more vertebrates than invertebrates.
24 SAQ 21.5Suggest why the Red List contains more vertebrates than invertebrates.One possibility is that people are much more aware of vertebrates than invertebrates, so we know more about them. They are larger and more visible than invertebrates. Many people find them more interesting than invertebrates.
25 Endangered species2011: western black rhino of Africa declared extinct by IUCNNorthern white rhino declared “probably extinct in the wild”It is thought that the last Javan rhino in Vietnam was killed by poachers in 2010Only the African southern white rhino is flourishing, up from only 100 individuals in start of 20th century
26 Endangered speciesRhino extinctions, despite years of conservation efforts, continue because of:A lack of political support for conservationAn increasingly high demand for rhino hornInternationally organized criminal groups targeting rhinos
27 Endangered speciesIn order to compile its Red List, IUCN must complete a new census of each speciesPopulation numbers are estimated using visual sightings, paw marks, bite marks, droppings, and DNA analysis of droppings
28 Rescuing endangered species Scimitar-horned oryx lives in semi-deserts in northern AfricaHas always been hunted for its meat and skin, but hunting grew exponentially starting in 1950sListed as endangered in 1960s and 70sA few oryx were caught and transported to zoos throughout the world
29 Rescuing endangered species Captive breeding program began with captured oryxCare was taken to maintain as much genetic diversity in captive population as possible, so oryx from several different zoos were mated using artificial insemination
30 Rescuing endangered species While captive breeding was taking place, attempts were being made to provide safe habitats for the oryx, so they could be returned to the wildLarge reserved set up in Tunisia1985: 10 oryx released to reserve2000: population has grown to over 120
31 Rescuing endangered species While the oryx program has been a success, some animals simple refuse to breed in captivityOften, it is not possible to create suitable habitats for them, so they cannot be returned to the wildEx: captive breeding program for Pandas. Since 1963, 300 pandas have been returned to the wild but no panda has been successfully returned to the wild
32 SAQ 21.6Suggest why some animals cannot be bred in captivity
33 SAQ 21.6 Suggest why some animals cannot be bred in captivity They may need particular factors in their environment before their reproductive systems become able to produce sperm or eggs – for example, to have plenty of space, or to have many others of their species around them. These factors affect their physiology and their behaviour. Courtship may be difficult in the conditions in which they live. They may need particular changes in day length or in food supply to trigger hormonal changes associated with reproduction.
34 Rescuing endangered species When animals in captivity refuse to breed, various techniques as well as artificial insemination can be used:Eggs can be collected from fertile females and fertilized by in-vitro fertilizationIn some species, another female of a closely related species can act as a surrogateIt is sometime possible to split early embryos, essentially cloning them
35 Rescuing endangered species In many species, sperm, eggs, and embryos can be stored frozen for later useSuch banks of frozen gametes and embryos from endangered species are called “frozen zoos”
36 Protection of endangered species Zoos and botanic garden help lead to public awareness and support for endangered animals and plantsMillennium Seed Bank: bank’s ambition is to collected and store seeds from at least 25% of the world’s plants so that if they become extinct in the wild, they can still be grown from seeds
37 Protection of endangered species 2007: beginning of Svalbard Global Seed Vault.Storage conditions ideal for long term preservation of seedsOpened only during winter monthsBy Jan 2008 vault held over 500,000 different crop varietiesTo maintain viability of seeds, every 5 years seeds are germinated and new seeds are harvested from resulting plants
38 Protection of endangered species To maintain genetic diversity, multiple seeds of the same species are storedEvery time a stored seed is germinated, it is cross pollinated to maintain genetic diversity
39 Protection of endangered species In order to safely store seeds, they must be dehydrated to contain only about 5% waterSome seeds, like rubber, coconut palm, and coffee cannot be dried and frozenThese seeds are referred to as recalcitrant seedsOnly ways to keep the genetic diversity of these species are to collect seeds and grow successive generations or to keep them as tissue culture
40 Protection of endangered species Coconut palm are particularly difficult seeds to bankThe seed (coconut) is very large and embryo is too large to freeze successfullyCollectors remove the embryos from the seeds, culture them in sterile tubes, and eventually plant them
41 SAQ 21.7It has been suggested that seed banks put selection pressure on the seeds that are different from those that plants would experience in the wild.How might these selection pressures differ?How might this affect the chances of success in returning the plants to the wild?
42 SAQ 21.7a Selection pressures in the natural habitat might include the ability of the adult plants to survive grazing, wide variations in rainfall or competition with other species. In the seed bank, none of these selection pressures would apply. In the seed bank, the greatest selection pressure will become the ability of the seeds to survive the conditions in which they are stored for a long period of time.b It is possible that the plants that grow from the seeds that have been saved will not have characteristics that will allow them to survive the selection pressures they will encounter in their natural habitat. This could reduce the chances of success in returning them to the wild.
43 Protection of endangered species Most countries now set aside areas where wildlife and the environment can live protected in the wild where human activities are limitedEx: conservation areas may be set up where there are strict limits on building, grazing farm animals, hunting, or other activities that would adversely affect native species
44 Protection of endangered species National parks are areas of land that are controlled by the government and are often protected by legislationThere are heavy restrictions on human activities in these parks, and tourism brings in money to pay for their maintenance
45 Protection of endangered species World’s first national park: Yellowstone National Park, set up in 1872Last remaining nearly intact ecosystem of the northern temperate climatic zoneServes as both a recreation and a conservation zone