Science 9 Unit A: Section 4.0. Textbook pages Science 9 Unit A Section Science 9 Unit A Section 4.0 2

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1 Science 9 Unit A: Section 4.0 Science 9 Unit A Section Textbook pages Science 9 Unit A Section

2 Species and ecosystems on Earth are being stressed by urbanization and the expansion of human industries such as agriculture and forestry. The extinction of some species, the decrease in population of other species, and the degradation of ecosystems reduces biological diversity on Earth. #1 Science 9 Unit A Section The dodo was a flightless bird that had no predators. Portuguese explorers that discovered them brought with them cats, rats, dogs, and pigs, all of which ate the birds and their eggs. The dodo became extinct within 200 years of first human contact. Science 9 Unit A Section

3 Science 9 Unit A Section Ecosystem Diversity Differences where interactions take place. Species Diversity Differences between different organisms within a GENUS. Genetic Diversity Differences at the cellular level. Science 9 Unit A Section

4 Extinction is the disappearance of every individual of a species from the entire planet. A natural part of Earth s history. Scientists estimate that 99% of all the species that have ever existed are now extinct (mostly by mass extinctions). #2 Science 9 Unit A Section The woolly mammoth coexisted with early humans. It disappeared from its mainland range about 10,000 years ago, most likely through climate change and consequent shrinkage of its habitat, hunting by humans, or a combination of the two. Cloning the mammoth is not yet possible because of the degraded state of the genetic material that remains. Science 9 Unit A Section

5 Most extinction takes place over long periods of time, but the RATE of extinctions is rising, and this reduces the biological diversity of our planet more rapidly. #3 The dodo bird; extinct within 200 years of first human contact Javan Rhino; only ~60 remain in Indonesia due to illegal overhunting Science 9 Unit A Section Extirpation is a local extinction, or the disappearance of a species from a particular area. Example: Grizzly bear #4 Science 9 Unit A Section

6 Example: The woodland caribou (Boreal forests of northern Alberta) Example: The swift fox (Alberta; restoration is underway and is now recovering) Science 9 Unit A Section In immediate danger of extinction or extirpation. Example: Red panda You can find the red panda at the Edmonton Valley Zoo! #4 Science 9 Unit A Section

7 Likely to become endangered if their current declines are not reversed. Example: Wood bison #4 Science 9 Unit A Section Particularly vulnerable to natural events or human activities. Example: Wolverine The wolverine, a solitary animal, has a reputation for ferocity and strength out of proportion to its size, with the documented ability to kill prey many times larger than itself! Facing a steady decline in the face of trapping, range reduction and habitat fragmentation. #4 Science 9 Unit A Section

8 In the past, most extinctions and extirpations were due to natural causes, such as: i. Catastrophic events (volcanic eruptions, earthquakes, floods, fires) ii. Lack of food due to overpopulation iii. Disease #5 Science 9 Unit A Section Overspecialization is another natural cause of extinction. It occurs when a species has adaptations that suit them to only a narrow set of environmental conditions. This probably happens because the environment that the organism inhabits remains unchanged for a very long time. Example: Giant panda, which only eats bamboo shoots #6 Science 9 Unit A Section

9 A generalist is an organism that is able to utilize different food sources or living environments and is therefore able to flourish in many habitats. Example: Mice, which can adapt to practically any environment and consume a variety of foods #6 Science 9 Unit A Section Because human populations continue to grow, and require land for houses and food production, human activity is now the leading cause of worldwide species loss. i. Habitat destruction ii. Introduction of non-native species iii. Over-hunting #7 Science 9 Unit A Section

10 Construction of buildings, agricultural development (i.e. clear-cutting in the Amazon Rainforest to create farmland), logging, and the damming of rivers and pollution (i.e. pesticides, herbicides, and fertilizers) all change environments. #7 Science 9 Unit A Section When introduced species use the same resources as native species, they compete with the native species and cause the number of native species to decline, simply because there is less of everything, and also because the introduced species has no native predator. #7 Science 9 Unit A Section

11 Science 9 Unit A Section Over-hunting was the major cause of the decline and eventual extirpation of the plains bison over most of its range, and of the extinction of the passenger pigeon (hunted for sport). Sometimes species were hunted to deliberately extirpate them. Blacktailed prairie dogs were considered a great menace to farmers and ranchers in the 1930s because they ate grain and dug holes causing cattle and horses to break legs. #7 Science 9 Unit A Section

12 Extinctions and extirpations reduce biological diversity. Extinctions reduce the number of species on the planet. Extirpations reduce biological diversity in areas from which the organism has disappeared. Example: Recall the over-hunted black-tailed prairie dogs. Well, these prairie dogs are the major source of food for black-footed ferrets, which are now one of the most endangered animals in North America. #8 Science 9 Unit A Section Textbook Check and Reflect Page 65 # 1 7 Read Topic 4.2 Page Science 9 Unit A Section

13 Textbook pages Science 9 Unit A Section My brother s dog! Buddy is a purebred English Labrador. This is him at about 1 year old! Science 9 Unit A Section

14 Recall that in natural selection, the environment selects traits. Organisms with the traits that are best suited for the changing environment will be more likely to survive and reproduce, thus passing on that trait to their offspring. This process usually takes many generations to occur. #9 Science 9 Unit A Section Artificial selection is the process of humans selecting and breeding individuals with desirable traits to produce offspring that have these desired traits. Only individuals with the desired trait (i.e. strong muscles, fast runners, shiny fur coat, etc.) will be allowed to reproduce. This process applies to plants and animals, both of which can be bred to possess desirable traits. #9 Science 9 Unit A Section

15 Plow Horse Racing Horse Science 9 Unit A Section Science 9 Unit A Section

16 Increase food production To create ornamental garden plants Medical research To create ideal pets and domestic animals Science 9 Unit A Section Biotechnology is the use of living things to make agricultural, industrial, or medicinal products. It is a process of intervention using low-tech or high-tech technologies, such as: i. Cloning (creating a genetically identical copy of an organism or its cells) ii. Artificial reproductive technology (any artificial method of joining a male and a female gamete) iii. Genetic engineering (directly altering the DNA of an organisms) #10 Science 9 Unit A Section

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19 In artificial insemination, sperm are harvested from a bull with desired characteristics and are inserted into many female cows. The advantage of this technology is that the bull s sperm can be in several places at once and more cows can be inseminated. #11 Science 9 Unit A Section Can you think of real-life situations where artificial insemination may be required to impregnate a woman? Consider a male with erectile dysfunction (i.e. produces too little sperm) Consider a quadriplegic male who wants to start a family with his wife Consider 2 women who want to start a family (without the presence of a male) Science 9 Unit A Section

20 In this technology, sperm from a prize bull and eggs from a prize cow are harvested from the animals. In a laboratory, the eggs and sperm are placed in a Petri dish, and the eggs are fertilized. This produces many more embryos than could be produced naturally. Each embryo is implanted into a different cow. These cows will eventually give birth to many calves, all of which will be brothers and sisters. #12 Science 9 Unit A Section Can you think of real-life situations where in vitro fertilization may be required to impregnate a woman? Consider a male with erectile dysfunction (i.e. produces too little sperm) Consider a quadriplegic male who wants to start a family Consider 2 women who want to start a family (without the presence of a male) Consider a female who doesn t release eggs (i.e. does not have a regular period/menstrual cycle) Consider a female who cannot carry her own baby in her own womb and uses the assistance of a surrogate mother Science 9 Unit A Section

21 Genetic engineering refers to any technology that directly alters the DNA of an organism. Genetic engineering is a rapidly developing science, and every new advance increases our ability to control the characteristics of organisms. Many of the genetic engineering techniques involve inserting a gene from one species into another species. #13 Science 9 Unit A Section For example, these are peanut leaves. In the top photo, the leaves have been extensively damaged by a certain type of larvae that feeds on the leaf. Scientists genetically altered the DNA of these leaves by injecting some of the genes of a certain type of bacteria into the DNA of the leaves. This bacteria acts as a natural pesticide and kills most of the larvae, allowing the plant to grow and preventing damage to its leaves. Science 9 Unit A Section

22 Risks in Animals Reducing genetic variation within a specific population Less resistance to disease Birth defects Unsuccessful pregnancies Deaths among clones Abnormalities Risks in Plants Resistance to herbicides Reducing genetic variation Interbreeding with weeds results in weeds offspring that are also resistant to herbicide #1 Science 9 Unit A Section Science 9 Unit A Section

23 Science 9 Unit A Section Textbook Check and Reflect Page 71 # 1, 2, 6, 7 Read Topic 4.3 Page Science 9 Unit A Section

24 Textbook pages Science 9 Unit A Section The conservation of biological diversity requires the elimination or reduction of the adverse impacts to biological diversity that result from human activity. In order to promote biological diversity, the Canadian Biodiversity Strategy (Canada signed it in 1992) focuses on insitu and ex-situ conservation, along with promoting the sustainable use of resources and an ecological approach to the management of human activities. #15 Science 9 Unit A Section

25 In-situ conservation refers to the maintenance of populations of wild organisms in their own functioning ecosystems. It allows the ecological processes of an area to continue undisturbed. #16 Science 9 Unit A Section Examples: National Parks (i.e. Banff and Jasper) Linking protected areas together (Yellowstone to Yukon Conservation Initiative) Wagner Natural Area (west of Edmonton; a protected land and miniboreal forest) #16 Science 9 Unit A Section

26 Ex-situ conservation refers to the conservation of components of biological diversity outside of a natural habitat. In some cases, ex-situ conservation offers the only chance of survival for some endangered species and plays an important role in conserving economically valuable genetic resources for forest, aquatic, and agricultural purposes. #16 Science 9 Unit A Section Examples: Seed banks (which store seeds from the many varieties of crop plants) Today, the world s seed banks are administered by an international group of scientists, known as the International Plant Genetics Resources Institute (IPGRI). IPGRI has instructed Canada to maintain the seed bank for barley and oats. Sperm and egg banks Zoos #16 Science 9 Unit A Section

27 Textbook Check and Reflect Page 78 # 1, 2, 3, 4, 6, 7 Unit A Review Handout & Study Guide Science 9 Unit A Section