Exam 4 Biodiversity Study GuideCh.1- BiodiversityBiodiversity-- Biodiversity is the variety of life and can refer to habitat, species, and genetic diversity, etc…- Developmental biodiversity- differences in the cells within the body- Genetic biodiversity- differences in genes- Geographical biodiversity- differences in life between geographical regionsVast number of species of life- There are between 1.5 and 2 million named species of living things on earth- Plants- 300,000- Fungi- 100,000- Bacteria and Protista- 100,000- Vertebrates- 50,000- Insects- 950,000Species-- Species are a population or group of populations of organisms that are very similar to one another (share a recent evolutionary history)- Important component of species is ability to interbreed - Linnean system of classification- binomial names (two names)- Genus species- ex. Homo sapiens (humans) homo is the genus name and sapiens is the speciesMeasuring Diversity-- Species Richness- number of species occurring in a particular area- Species Diversity- combination of number of species and relative number of individuals of each species- Know the differences between these two ^- Two areas can have the same number of species so in this case the evenness of those species determines which is diverse- Species are NOT spread out evenly throughout the world (tropical areastypically have more species than temperate ones)Ecosystems-- Ecosystems are a combination of both the abiotic (living) and biotic (nonliving) organisms- Ecosystem services- something such as oxygen, fresh water, or food that is provided by an ecosystem by its speciesGenomics- - Genomics is the new use of the comparative method- Genome- entire set of genetic material in a cell- Allele- particular version of a gene.- Source of genetic variation is individuals having different allelesHuman Impact on Biodiversity-- Negative due to human interactions such as pollution, agriculture, etc.- We are currently going into the world’s 6th mass extinction event- Current extinction rates are between 10 and 100 times higher than those estimated from the fossil recordCh.2- EvolutionPopulational Thinking-- Populational Thinking is a way of looking at the world. Views people, animals, bacteria, cities, etc. as being parts of a population of similar things- Individuals are bing influenced by many factors so it can be hard to say the cause of something is- Typologically- assigns different things to categoriesEvolution-- Evolution- is based on variation with natural selection being the primary mechanism of evolution. Characteristics that help organisms survive and reproduce will become prevalent in that environment- Three things that must occur for evolution to occur- competition (more born than survive), inheritance (pass traits to offspring) and variation (individuals all have different traits)- Charles Darwin- traveled on the HMS Beagle to the Galapagos Islands wherehe studies the plants and animals of the island and compared them to organisms found on other continents. This prompted his idea of evolution.- Darwin’s two main ideas were descent with modification and natural selection (tree of life)- Darwin believed many of the species found on these islands had evolved from other mainlands and were similar to species found in South America and concluded that South America colonized these islands- Evidence of evolution- life on islands, homology, fossil record)- Alfred Wallace- learned about biodiversity by traveling through the Amazon and Southeast Asia- Stabilizing selection- genetic diversity decreases as the population stabilizes on a particular trait value- Disruptive selection- population tend to diverge into two different groups- Directional selection- common in response to change in environment- Reproductive Isolation- allows for independent evolution- Standard Deviation- measure of the amount of variation in a population- Species are formed through some sort of geographic isolation- Population Variation can make the ling between cause (smoking) and effect (cancer) less straightforwardChapter 3- EcologyEcology- - Ecology- study of factors influencing the distribution and abundance of organisms- The world is divided into many different biomes determined by three factors- temperature, precipitation, and seasonality- Seasonality is important in distinguishing the desert and Mediterranean habitats- Natural selection will act on different characteristics in different parts of the world and even within an ecosystemEcological Niches-- Ecological Niches is the ecological “role” of the species and allow organisms to split the environment into different pieces so many species can live within a community- Can be a range of things- microclimate, pollution tolerance, food eaten,etc.- Community- all the species in an area- Parasitoids- alter the behavior of their hosts (ex. Rat and toxoplasmosis)- Three main types of species interaction- predation, competition, and mutualism- Predation includes eating plants, parasites, and parasitoidsFood Web-- Primary Producers- make own food and carbon through photosynthesis. Non-photosynthesizing producers eat plants to gain carbon- Decomposer- feed on dead organic matter- Only plants can bring energy into an ecosystem- Nitrogen fixing bacteria are required to supply ecosystems with nitrogenDisturbances-- Influence the number of species within a community and leads to succession (environment changes over time until it goes back to how it was)- An intermediate amount of disturbance> high diversity. Needed for biodiversity- Too little disturbance> low diversity species become highly specialized and hard for new species to come in- Too much disturbance> low diversity. It doesn’t allow for species to thrive before it is destroyed again (ex. Agriculture)Chapter 4- AgricultureArtificial Selection-- Selective breeding-humans choose individuals with desirable traits. The smaller sample size leads bigger and more drastic results- Selective breeding can lead to a loss of genetic diversity which is a problem due to a long term selection leading to vulnerability to diseases- Genetic engineering/modification allows much more specific manipulation of genes and is done through the use of virusesMonoculture-- Monoculture focuses on growing one plants species- low diversity high disturbances which makes them vulnerable to pests and weeds- Planting more species together can increase resistance to pestsCh.5 Medicine- The immune system works by
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