environmental unit 1 (week 1-3)
Data indicate that we have overshoot Earth's biocapacity - it's capacity to support us - by 50%. We are using renewable natural resources 50% faster than they are being replenished About how many times larger was the global footprint in 2007 than it was in 1962?
2 The global ecological footprint was about 1.5 in 2007 and about .75 in 1962. This is about two times as large.
Mes activity question 1 causes and consequences of ecological footprints
Causes: -rising per capita affluence -strong Dem and for material goods -cultural influences that encourage consumption Consequences: -habitat loss and ecosystem degradation -excess waste and pollution of air, water, and soil -depletion of natural resources solutions: -sustainable harvest of resources -enhanced technologies to reduce impacts of goods and activities -improved efficiency of manufacturing processes -adoption of cultural changes to reduce desire for consumption unintended consequences: -steps to reduce consumption could in some cases cause economic loss, especially to poorer people new solution: -steps should aim to maintain people's quality of life in the face of declining material consumption
Question to check reliability
Is it current? Provide sources and are they reliable? Purpose - inform or persuade, sell, entertain? Date of publication appear? Who is responsible for the information? Lots of ads?
variable
a condition in an experiment that can change
paradigm shift
a fundamental change in approach or underlying assumptions.
data
information obtained from scientific studies
Example: "Is Biden destroying 11,000 jobs by revoking the keystone XL pipeline?"
"Democrats couldn't even get through Day 1 without killing jobs for middle class Americans" no signature, many different estimates, social media TC Energy Corp - about 1,000 people temporary unemployment Symbol for political debate over fossil fuels History - request denied in 2015, executive order in 2020 to allow, halted for endangered species review. More of a statement about what "could be" - contracts would hire about 7,000 workers
Issues related to population growth
-Human population -Electric cars -Wildfires -Wildlife -Water -Trash -Air pollution
Which two statements are supported by the data in the graph?
-The global ecological footprint has generally increased over time, with brief periods of decrease -In 1970, we began to overshoot Earth's capacity to support us As the graph shows, we are depleting renewable resources by using them 50% father than they are being replenished. This excess use has been termed overshoot because we are overshooting or surpassing, Earth's capacity to sustainably support us
groups
-subject -summmary of articles -how influenced by human population -Examples of reliable, unreliable
Article: "As World's Population Booms, Will Its Resources Be Enough for Us?" Questions for review - 1)What was the human population in 2011 (this was a major milestone reached). 2)What did a new UN study show about human population growth?
1) World population passed 7 billion on October 31, 2011, according to the United Nations. These estimates are based on assumptions about existing population size and expectations of fertility, mortality, and migration in a geographic area. 2) The new UN study out this week projects that the world's population growth may not stop any time soon. That is a reversal from estimates done five years ago, when demographers—people who study population trends—were projecting that by 2045, world population likely would reach about 9 billion and begin to level off soon after.
TED Talk: Questions for review - 1)What's wrong with the study that shows red wine can reduce your chance of breast cancer? 2)What did the "placebo" effect mean for students in the fish oil study?
1)- "Red wine could help prevent great cancer" -"A glass of red wine a day could help to prevent breast cancer, a new study shows" [It's a description of the changes in the behavior of one enzyme] [when you drive a chemical extracted from some red grape skin on to some cancer cells in a dish on a bench in a laboratory it's useful to describe it in a scientific paper] [your risk of cancer increases slightly with every amount of alcohol you drink, so what we want are studies in real human people] 2)- "claim: fish oil pills improve school performance and behavior in mainstream children, all previous trials were positive this one will be too. They were taking 3,000 children, they were going to give them huge fish oil pills, 6 of them a day, then a year later measure their school exam performance and compare their performance against what they predicted their exam performance would have been if they hadn't had the pills flaw: no control group placebo effect: beliefs and expectations can be manipulated, comparing a treatment to nothing instead of another treatment to see which is better, making decisions in the absence of all of the information
To practice your interpretation of p-values, decide if each of the p-values below indicates that you should reject your null hypothesis PRACTICE PROBLEM #1 1. p = 0.11 Reject or Do Not Reject Ho? 2. p = 0.56 Reject or Do Not Reject Ho? 3. p = 0.99 Reject or Do Not Reject Ho? 4. p = 0.01 Reject or Do Not Reject Ho? 5. p < 0.005 Reject or Do Not Reject Ho?
1. do not reject Ho 2. do not reject Ho 3. do not reject Ho 4. reject Ho 5. reject Ho
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part b) according to the graph with the logarithmic scale, after 200 generations the population had
1000 individuals After 200 generations, the population has approximately 10^3 or 1000 individuals
Lab3Q5: When reporting the results of an experiment, it is often useful to use a data table. An effective data table should....? 1. be numbered sequentially, beginning with Table 1 2. have a descriptive title 3. have clear column and row headings 4. identify the units of measurement for the data presented 5. All of these answers are important components of an effective data table
5. All of these answers are important components of an effective data table
ecological footprint part b If the world population was using only 50% of Earth's biocapacity in 1961, that would represent a global ecological footprint of a) 5.0 planet Earths b) 0.5 planet Earths c) 1.0 planet Earths d) 2.0 planet Earths
50% of Earth's bio capacity represents 0.5 planet Earths
Lab2Q9: station 1: 4 ft station 2: 7 ft station 3: 2 ft station 4: 5 ft station 5: 5 ft station 6: 6 ft station 7: 8 ft station 8: 11 ft station 9: 15 ft what is the median of the data gathered?
6
Lab2Q2: Determine the mean of this data set: 97, 93, 90, 88, 88, 85, 83, 82, 77, 75, 74, 71, 69, 66, 59
79.8
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part a) according to the graph with the linear scale, the population reached 8 billion individuals after approximately ____ generations
900 the population reached 8 billion individuals after approximately 900 generations
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part c) according to the graph with the linear and logarithmic scales at 400 generations shows that:
Although you cannot read the exact value from the linear-scale graph, the population size is the same, just shown with different scales Linear and logarithmic scales are two different ways of graphing the same data
Lab3Q2: In the high schooo football "loaded coin" example, what is a good way to examine the potential outcome of coin flipping so they can test if it is really loaded or not?
Binomial distribution
Lab2Q8: If your data are_____(each point is directly related to the next and can be connected by an infinite number of intermediate points), then a_____s the way to go in presenting that data
Continuous, line graph
Figures
Figures include illustrations, diagrams, maps, and graphs, and can be extremely useful in scientific writing The ultimate goal of science writing is to present information to the reader concisely, but completely Illustrations can be used to identify structures in an organism, or to show a new species or experimental apparatus. Diagrams are often used to show the relationship between variables in complex systems, or to visually depict a chemical reaction or other sequence of events. Maps are most commonly used to show the locations of sampling sites when experiments are conducted in the field. While using these types of figures can be helpful, their overuse can be detrimental. Formatting characteristics for illustrations, diagrams, and maps: (a.) Each illustration/diagram/map is numbered sequentially, beginning with Figure 1. (b.) The title of the illustration/diagram/map should be descriptive, allowing readers to interpret the table based on the title alone. (c.) The illustration/diagram/map should be of high quality and appropriate size.
Choosing the Values to Graph
First, we determine that a bar graph is most appropriate, as the independent variable is the two groups, and this is categorical, not continuous. Second, we must determine what to graph. There are 20 bars, 2 categories, and lots of different group numbers of mix things up. If we take a step back and look at the study, what we're really interested in doing is comparing the hatching success in groups exposed to pesticide and the groups not exposed to pesticide. So what we really want to do is to graph the mean of the two groups and compare them to one another Knowing the spread of the data can be important in making conclusions, so you need to provide the reader with this information. This is done by adding "error bars" to data points or bars on a graph that indicate the standard deviation of the data In bar and line charts, error bars are drawn both above and below the mean to a distance equal to their value. Realize that error bars are only appropriate when graphing a group's mean. including error bars can make a big difference in your interpretation of a graph.
Descriptive Statistics
Measures of Central Tendency interested in knowing the "center" of the group of values There are three such measures of central tendency: the mode, the median, and the mean To examine measures of central tendency, it is helpful to arrange the values in descending order. numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.
We live on a finite planet and sometimes our impact on it is greater than we realize. The seemingly isolated actions we take every day—from our choice of morning beverage to our choice of business practices—are often links in a chain of unusual connections we would never have imagined. Our impact on this planet is sometimes greater than we realize. Questions for review - So how much water does it actually take to produce your morning latte?
How much water does it take to make one latte?: -a Lott of other things in your latte use water in their production: -water -lid -cup and sleeve -sugar -milk -coffee it takes 200 liters of water which is more than 50 gallons effects: -takes away from earth's water supply solution: -change how we farm and process coffee -we can produce more coffee using less water
Variance and Standard Deviation
In most cases, we are interested in knowing how far each of the data points is from the mean or median of the data set So let's determine the individual point deviations for the original exam score data set by subtracting each score from the mean. we need to look at the absolute values of the deviations, and one way to do this is to square each of them and add them up. If we divide this sum by one less than the number of values, this will give us the variance of each data point. The variance describes how far each value is from the mean We can undo the squaring by taking the square root of the variance, which will provide us with a measure of data dispersion in the same units as the mean. This value is known as the standard deviation (SD).
manipulative experiment
O - there sure is a lot of algae on that pond Q - what causes surface algae to grow on pond? H - Fertilizer runoff is increasing algae P - If fertilizer is added, the algae will increase T (experiment) - Independent variable (fertilizer), dependent variable (response - algae growth). Need a control - pond. that does not get the fertilizer R - Dry mass of algae or surface cover % compared between 2 ponds
As population booms, will earths' resources be enough for us?
October 31, 2011 - we passed 7B (adding a B every 12-13 yrs recently) United Nations - highly likely 9.6B by 2050 to 11B by 2100 Other experts - 9.4B decreasing to 9B by 2100 Thomas Malthus predicted we will starve (800 million don't have enough to eat now) Now - not population so much as our dramatic rise in resource use - "The Great Acceleration" Oceans are a great example Our footprint tells the story globally
(article)The plight of Phoenix: how long can the "least-sustainable" city survive?
Twenty years ago, Anthem, Arizona sprung out of the bare desert, a community "master-planned" from scratch with schools, shops, restaurants, spacious homes - many behind high walls and electronic gates - and its own country club and golf course. It now has a population of 30,000. Lush vegetation and ponds do not occur naturally. Phoenix gets less than 8inches of rainfall each year. Most of the water supply for central and southern Arizona is pumped from Lake Mead, which is fed by the Colorado River more than 300 miles away. Anthem's private developer paid a local Native American tribe to lease some of its historic water rights. The developer pipes the water from the nearby Lake Pleasant reservoir, which is also filled by the Colorado The Colorado River is drying up, though. In the winter of 2017 to 2018, snow in the RockyMountains, which feeds the Colorado, was 70 percent lower than average. 2018, the U.S. government calculated that two-thirds of Arizona was facing severe to extreme drought. Temperatures in Phoenix remain above 98 degrees on summer nights, and this is due to the "heat island" effect. A heat island is an urban area that is warmer than its surrounding areas due to human activities. (Downtown Phoenix) The area is still growing - and is dangerously stretched thin, experts warn. There are plans for substantial further growth and there just isn't the water to support that," says climate researcher Jonathan Overpeck, who co-authored a 2017 report that linked declining flows in the Colorado River to climate change. He called Phoenix the "urban bulls-eye for global warming in North America" Bill Gates recently invested $80 million in a company that aims to construct 80,000 new homes on undeveloped land west of Phoenix, as well as a highway to Las Vegas. Another company wants to build a "master-planned community" like Anthem south of Tucson, Arizona. The company hopes to construct five golf courses, a vineyard, parks, lakes and 28,000 homes. The promotional video contains no details about where all the water will come from, but it boasts: "This is the American dream: whatever you want you can have." What these cities want is water. The Phoenix area draws from groundwater, from small rivers to the east, and from the mighty Colorado. The Hoover Dam holds much of the Colorado's flow in the vast Lake Mead reservoir, but the river itself is sorely depleted. That water has now dropped to within a few feet of levels that count as official shortages in some states. California, Nevada and Arizona all rely on this water. Lake Powell, the reservoir at the other end of the Grand Canyon, similarly averages half its historic levels. In 2012, government experts reported that droughts of five or more years would happen everydecade over the next 50 years. Still, the greater Phoenix area has not declared any water restrictions, and the state government has not decided on its official drought contingency plans. The conversation in Arizona turns to extreme ideas, such as drawing water from the Great Lakes 1,700 miles away or building expensive desalination plants, which can remove salt from ocean water and turn it into drinkable water. Greater Phoenix is good at recycling waste water, but most of it is used for cooling the Palo Verde nuclear power plant to the west of the city. It's the largest power plant in the United States and theonly one not on its own body of water. It turns out that water department is Arizona's biggest electricity consumer because it has to pump the water uphill from the Colorado River along miles of canals into Phoenix and Tucson. Andrew Ross says low-income neighborhoods on the more polluted south side of the Salt River(which flows through the city), would be less able to protect themselves from the heat and drought than wealthier citizens. He calls this situation "eco-apartheid."
Lab3Q10: Why is the metric system so important to use in science?
Science is an International language and so needs a standardized unit of measurement
Lab2Q10: There is an election coming up this year (you will vote, right?) and you will see plenty of these from every candidate to back their position and discredit their opponents' point of view. They allow us to summarize large volumes of mathematical information, and so are found wherever there's data to be presented
Statistics
The ecological footprint of an average ____ citizen is much greater that that of some of a developing country
U.S.
(article) Oil drilling in Alaska wildlife refuge is part of U.S. Senate tax bill
The U.S. Senate passed a sweeping, $1.4 trillion tax bill. The bill cuts taxes for big businesses and the wealthy, and how it may hurt the poor. However, one issue has been buried, and it's stirring concern among conservationists and other nature lovers: a proposal to allow drilling for oil in Alaska's Arctic National Wildlife Refuge (ANWR). It is a vast region in northeastern Alaska, and businesses hoping to drill there have called it a "frozen desert." Scientists say this wilderness actually overflows with life, as the photo above suggests. They are fighting to get that plan out of the tax bill before it becomes law. More than 200 species make the refuge home, including caribou, wolves, Arctic fox, 36 species offish, and millions of birds, from snowy owls to northern pintails. Many species find critical homesthere during migration. Covering more than 19 million acres of Alaska's North Slope, the refuge is the largest in the U.S. --a little bit bigger than South Carolina. The ANWR is the only refuge in the country that is home to grizzly bears, black bears, and dens, or habitats for polar bears, and it provides a wildlife corridor that stretches from the Canadian border across Alaska to the Chukchi Sea. Drilling advocates have argued for decades that oil and gas can be safely extracted there. However,environmentalists are quick to point out that accidents are possible and have happened on morethan one occasion. Earlier this month, 37 leading Arctic wildlife scientists wrote a letter urging Congress to block drilling in the refuge. That's still a possibility, as the bill is being reviewed by Congress now before it is fully approved. Support for drilling is being driven by Alaska's senators. The refuge was established in the 1960s to protect wilderness and wildlife. But the oil industry has often complained that it also holds an estimated 10.3 billion barrels of petroleum oil under the ground. Republicans have long argued that the refuge holds the keys to energy independence which inother words would make the U.S. less reliant on other countries for oil. They also think it couldbring more wealth and jobs to the U.S. Meanwhile, Democrats have often said oil and gas drillingwill disrupt delicate ecosystems and the communities that rely on them. Typically, Yarnold notes, oil and gas companies must follow certain rules about thewildlife and environment around them as they drill for oil. But this bill, he says, makes drilling themain focus, not the plants and animals that live nearby.
ecological footprint part c one criticism of the ecological footprint methodology is that it ignores human population growth. If this criticism is correct, which of the following statements would also be true?
The ecological footprint is likely to underestimate the future natural capital needs of the planet our growing population will continue to need more resources
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part d) suppose that the initial population was 10, but the graph growth rate was 5% (instead of 2.3%). How would the linear-scale graph differ?
The linear graph would show rapid population growth beginning at an earlier generation A higher growth rate means more rapid population growth, which would show up earlier on the linear-scale graph.
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part f) Which statement is true about pros and cons of representing data on the two graph scales?
The linear-scale graph clarifies the timing of rapid population growth while the logarithmic scale graph simplifies identifying actual population sizes as a population goes from quite small to quite large Linear and logarithmic scales are useful for different reasons
Environmental scientists study phenomena that range in size from individual molecules to the entire Earth and that occur over time periods lasting from fractions of a second to billions of years. To simultaneously and meaningfully represent data covering so many orders of magnitude, scientists have devised a variety of mathematical and graphical techniques, such as exponential notation and logarithmic scales below are two graphical representations of the same data, representing the growth of a hypothetical population from an initial size of 10 individuals at a rate of increase of approximately 2.3% per generation The graphic part (a) uses a conventional liner scale for the population size; the graph in part (b) uses a logarithmic scale part e) suppose that the initial population was 10, but the graph growth rate was 5% (instead of 2.3%). How would the logarithmic-scale graph differ?
The logarithmic graph line would have. a greater slope than the graph shown A higher growth rate would result in a line with greater slope
Graphs
The type of figure you will use most frequently is a graph. Like tables, graphs present data to the reader, but do so in a visual manner that it often superior to tables Note that the independent variable is graphed on the x-axis and the dependent variable on the y-axis, the x-axis (horizontal) and y-axis (vertical) are labeled, units are listed where appropriate If "time" is a factor in your graph, it should be graphed on the x-axis The scaling of the axes is an area that tends to give students trouble The scale on an axis should cover the range of values in your data set, and does not have to start at zero start slightly below lowest value and slightly above greatest value divide the increments between equally scaling can make a big difference in data interpretation. The graph on the left seems to suggest no difference in pH level in the two treatments, but with proper scaling the differences in the groups become apparent There are exceptions to this rule, though. If you are comparing percentages (e.g., exam scores), it is conventional that you make the axis run from 0% to 100%
Binomial Distribution
This distribution describes the probabilities for events when you have two possible outcomes (heads or tails) and independent trials (one flip of the coin does not influence the next flip). ex: shape of the curve with 50 trials is much smoother than the curve for 10 trials, and more representative of a normal curve
Let's assume that a researcher is attempting to determine the effects of pesticide pollution on the hatching success of fish eggs. He has noticed that fish eggs in streams near agricultural fields fare poorly, while those is undisturbed areas hatch successfully. The researcher sets up a lab experiment in which ten groups of fish eggs are allowed to develop in unmanipulated stream water, and ten groups of eggs develop in stream water with the addition of pesticide. The proportion of eggs hatching in each group is tallied (Table 1), and descriptive statistics for the two groups compared. Table: Effects of pesticide pollution on hatching success of fish eggs. Proportion eggs hatching [(Group 1)(No Pesticide = 0.80)(Pesticide = 0.50) (Group 2)(No Pesticide = 0.76)(Pesticide = 0.45) (Group 3)(No Pesticide = 0.81)(Pesticide = 0.68) (Group 4)(No Pesticide = 0.90)(Pesticide = 0.77) (Group 5)(No Pesticide = 0.95)(Pesticide = 0.64) (Group 6)(No Pesticide = 0.84)(Pesticide = 0.60) (Group 7)(No Pesticide = 0.88)(Pesticide = 0.54) (Group 8)(No Pesticide = 0.99)(Pesticide = 0.57) (Group 9)(No Pesticide = 0.86)(Pesticide = 0.62) (Group 10)(No Pesticide = 0.93)(Pesticide = 0.57)] Statistic [(Mean proportion eggs hatching)(No Pesticide = 0.87)(Pesticide = 0.59) (standard deviation)(No Pesticide = 0.07)(Pesticide = 0.09)]
To compare these two data sets, we must first state our hypothesis. Our null hypothesis would be that the two groups are not different, and that both data sets belong to the same distribution. Ho: The mean proportion eggs hatching in the two groups is not different OR Ho: The two experimental groups are part of the same distribution We then conduct a t-test on the data set, which will examine the differences in mean and dispersion in the two groups, and provide a probability that the two groups are part of the same distribution. t-statistic: 7.56 p<0.0005 As the p-value returned by the test was less than 0.05, we can reject our null hypothesis, conclude that the two groups are indeed from different distributions, and that they are significantly different from one another. researcher can therefore conclude that pesticide exposure reduces the hatching success of eggs of this species
Inferential Statistics: Probability
We are therefore essentially testing the hypothesis that the observed data fits a particular distribution Given that 95% of the values in a distribution fall within two standard deviations of the mean, statisticians have decided that if a result falls outside of this range, you can determine that your data does not fit the distribution you are testing whenever a statistical test returns a probability value (or "p-value") equal to or less than 0.05, we reject the hypothesis that our results fit the distribution we are testing
ecological footprint part e If Mathis Wackernagel and Ian Moffat were to engage in a debate about the usefulness of the ecological footprint, Mathis Wackernagel might conclude by saying the ecological footprint is the best tool we have to measure sustainable resource use and we are refining the methodology. Ian Moffat might conclude his remarks by saying: a. making policy decisions based on unscientific methodology is a mistake b. we are ready to continue addressing the problem of conspicuous consumption c. clearly, the ecological footprint has overestimated global overshoot d. The ecological footprint should be abandoned because of its flaws
a. making policy decisions based on unscientific methodology is a mistake
t-test
a statistical test that compares the distributions of two data sets to one another an inferential statistic that enables you to compare the means of two groups and determine if they are statistically different from one another *compares both the means and distributions of data sets in order to determine if they are different from one another the test compares the distributions of the two data sets to one another, and tests the hypothesis that the two data sets belong to the same distribution. If there is a low likelihood that the two data sets belong to the same distribution (probability less than or equal to 5%), then we can conclude that true differences in the means of the two groups exist, and the two groups are significantly different from one another. looks at the ratio of the difference in group means to variability, in essence taking the ratio of the "signal" (the means) versus the "static" (the variance).
sustainability
a way of living so that the Earth's resources can sustain us well into the future
science, technology, and society: DDT Part A In animal populations, DDT causes____ a. birth defects b. tuberculosis c. sleeping sickness d. the flu e. malaria
a. birth defects In animals, long-term exposure to DDT can cause death of severe birth defects
science, technology, and society: DDT Part B DDT is____-soluble so it accumulates in____. a. fat...milk b. water...milk c. water...streams d. fat...streams e. water...oceans
a. fat...milk fat-double DDT accumulates in the fats of milk and from there can be transferred to children
ecological footprint part d a second criticism of the ecological footprint is the possibility that the current estimate of 25% global overshoot may be incorrect if humans are in fact still below global biocapacity, that implies: a. we may need to change some of our practices, but we have more time to make those adjustments b. It's already too late for change-- our civilization is headed for collapse c. all our practices are sustainable d. We can increase our natural resources without cause for concern
a. we may need to change some of our practices, but we have more time to make those adjustments Shifting to more sustainable practices can reduce the chance of ecological overshoot
Hypothesis
aa testable statement that attempts to answer a scientific question
Statistics
allow us to summarize large volumes of mathematical information, and so are found wherever there's data to be presented Collection of methods for planning experiments, obtaining data, organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on data. The most recognizable use of statistics for the typical college student is when exam grades are posted. your score and the class average class average matters because it is an easy way for you to compare your performance with the "average" statistics can be important when comparing players' performance Statistics also play a prominent role in politics The gathering and analysis of data forms the backbone of science Statistics are used to describe numerous parameters (temperature, growth rates, age, etc.) and to make comparisons between experimental groups
control
an unmanipulated point of comparison for treatments in an experiment
ecological footprint part a According to Mathis Wackernagel, ecological overshoot is caused by an overuse of resources. Which of the following practices could contribute to ecological overshoot? a) replanting trees as timber is harvested b) catching fish more rapidly than the population can sustain c) recycling materials after they are used d) switching to renewable energy sources with lower CO2 emissions
b) catching fish more rapidly than the population can sustain
removing lead from gasoline part c following the ban of lead from U.S. gasoline, scientists played an important role in measuring the subsequent impact on human health The following graph shows the amount of lead used in gasoline (metric tons per year) and the average blood lead concentration (micrograms per deciliter) in U.S. children (ages 1-5) between the years 1970 and 2010 As a researcher, you have been asked to analyze trends in the decline in lead use in U.S. gasoline over time. Based on the data in the graph, by what percentage did the amount of lead used in gasoline decrease between the years 1970 and 1985? a. 50% b. 80% c. 100% d. 20%
b. 80% The total amount of lead in U.S. gasoline went from approximately 250 metric tons in 1970 to approximately 50 metric tons in 1985, or an 80% decline
Lab2Q4: Humans are a visual species (hence, "a picture is worth a thousand words"), and figures are therefore beneficial in that they depict information visually. What type of graph is pictured below:
bar graph
Lab3Q8: In order to "think like a scientist" rather than "like a student," you should:
be critical of what you read or hear
red wolf research- natural experiment
observation, question, hypothesis, prediction, test, results
science, technology, and society: DDT part c a. DDT does not help prevent disease from passing from agricultural animals to humans b. Cost was a major factor in the United States government's decision to ban DDT c. Many African governments concluded that the potential long-term health effects of DDT were not as serious as the immediate problem of insect control d. DDT cannot accumulate in the fat of animals e. The DDT ban in the United States has made it very difficult to control agricultural in sect pests
c. Many African governments concluded that the potential long-term health effects of DDT were not as serious as the immediate problem of insect control they concluded that the immediate benefits of DDT outweigh the possible long-term harmful effects
ecological foot print
causes, consequences, solutions total amount of functioning ecosystem needed both to provide the resources a human population uses and to absorb the wastes that population generates the impact of a person or community on the environment, expressed as the amount of land required to sustain their use of natural resources. "an average amount of productive land, fresh water, and ocean required to supply the person food, wood, energy, water housing, transportation and waste disposal."
removing lead from gasoline part b following the ban of lead from U.S. gasoline, scientists played an important role in measuring the subsequent impact on human health The following graph shows the amount of lead used in gasoline (metric tons per year) and the average blood lead concentration (micrograms per deciliter) in U.S. children (ages 1-5) between the years 1970 and 2010 pretend you are a public health official giving a presentation to the local community about the dangers of lead exposure as you show data from the graph in the previous part, what is the most important "take home" message you might share with audience, based on the relationship between the amount of lead in gasoline and blood lead concentration in children between the years 1970 and 2010 a. Although there was a considerable decline in both the amount of lead used in gasoline and average blood lead concentration between 1970 and 2010, the graph suggests that there is still considerable work to be done in further reducing levels in gasoline b. despite a steep drop in the use of lead in gasoline from 1970 to 2010, average blood lead concentration in children changed little during this time suggesting that lead exposure is not as harmful as what was once believed c. As the amount of lead in gasoline dropped sharply from 1970 to 1990, the average blood lead concentration increased steadily in children, indicating that the lead ban in gasoline was not a successful strategy reducing human lead exposure d. A sharp drop in the amount of lead used in gasoline was followed by a similarly sharp decline in blood lead concentrations in children between 1970 and 1990, suggesting the lead use in gasoline was strongly correlated to lead exposure, and the ban on lead had a major impact on reducing exposure in the United States
d. A sharp drop in the amount of lead used in gasoline was followed by a similarly sharp decline in blood lead concentrations in children between 1970 and 1990, suggesting the lead use in gasoline was strongly correlated to lead exposure, and the ban on lead had a major impact on reducing exposure in the United States The graph shows a clear parallel between the decline in the amount of lead used in gasoline and the decline in blood lead concentrations in children between 1970 and 1990 in the United States. This relationship supports the conclusion that much of the lead exposure was the result of lead use in gasoline, which is why the lead ban was so successful in reducing human exposure to lead.
removing lead from gasoline part a following the ban of lead from U.S. gasoline, scientists played an important role in measuring the subsequent impact on human health The following graph shows the amount of lead used in gasoline (metric tons per year) and the average blood lead concentration (micrograms per deciliter) in U.S. children (ages 1-5) between the years 1970 and 2010 Based on this data, which statement is most accurate regarding the change in lead use in gasoline and average blood lead concentration in children over time? a. although there was a brief increase in the amount of lead used in gasoline for a few years following 1975, this was not followed by a similar increase in average blood lead concentration in children b. based on the data, there is no clear correlation between the amount of lead used in gasoline and the average blood lead concentration in children between 1970 and 2012 c. as lead use in gasoline declined to zero by 1995, the average blood lead concentration in U.S. children to rise until 2010 d. both lead use in gasoline and blood lead concentration in U.S. children declined most rapidly between 1975 and 1985
d. both lead use in gasoline and blood lead concentration in U.S. children declined most rapidly between 1975 and 1985 based on the graph, both the amount of lead used in gasoline and average blood lead concentration in children dropped more rapidly during 1975-1985 than in any other time period between 1970 and 2010
range
describes the highest and lowest values in a data set is commonly used in weather reports, high and low temperatures are reported
Lab3Q9: t-statistics: 0.9640 p-value: 0.3633 Ho: the two experimental groups are part of the same distribution using the data above, where the p-value = 0.3633 do you accept or reject the null hypothesis?
do Not reject the null hypothesis (Ho). By conventional criteria, this difference is considered not to be statistically significant. (not equal to or under 0.05)
Lab3Q4: p = 0.56 Reject or do not reject the null hypothesis?
do not reject (not equal to or under 0.05)
peer review
evaluation of scientific, academic, or professional work by others working in the same field.
Measures of Dispersion
having an idea of the spread (dispersion) of data points is necessary to accurately interpret a data set we will look at three measures of dispersion: the range, variance, and standard deviation
Ecological footprint You have learned that one of the ways to quantify human impact is by calculating an ecological footprint for an individual, or a population. Follow this link to the Global Footprint Network to learn more about ecological footprints, and how they are calculated. Questions for review - How many earths do we need to accommodate the resources we are currently using globally? (FYI this is different for the US and the globe). https://data.footprintnetwork.org/#/
highest for each between 1961-2018 canada: 5.41 earths Central African Republic: 1 chad: 1.37 Chile: 2.71 etc. etc.
Ecological footprint measures
how fast we consume resources and generate waste carbon footprint -> energy built-up land -> settlement forest -> timber & paper cropland & pasture -> food & fiber Fisheries -> seafood
t-test calculator
http://www.graphpad.com/quickcalcs/index.cfm (1.) Select the "Continuous data" option, then the "Continue" button. (2.) Select the "t test to compare two means" option, then hit the "Continue" button. (3.) Simply enter your data in the columns by group, select "Unpaired t-test", and then hit the "Calculate now" button. Your p-value and t statistic will be listed on the results page [For a given data set to be suitable for analysis with a ttest, it must meet two assumptions: (1.) the variance in the two groups being compared cannot be significantly different from one another, and (2.) the data must roughly fit a normal distribution]
Lab3Q6: In the Basic Skills lab module capstone, what were you supposed to compare for the final experiment?
leaf/needle size
Lab2Q5: What type of graph would you use to represent the rate at which a child grow in height?
line graph
Lab3Q7: inferential statistics....?
may be used to make comparisons between data sets
Mean
mean of a data set, commonly called the "average". you sum all of the values and divide by the number of values
Central Tendency and Dispersion
mean, coupled with the standard deviation, is a good way to summarize a data set as it provides the reader with a measure of both the central tendency and the dispersion of the data. You should not, however, always limit yourself to these two statistics
Lab2Q11: When looking at a data set, scientists are often interested in knowing the "center" of a group of values. Which of the following are measures of central tendency?
mode, median, and mean
interdisciplinary
natural and social sciences
Lab2Q3: In statistics, standard deviation is useful when coupled with the mean because it allows us to examine the dispersion of a data set quickly and easily. In the picture below, which colored area shows data points which fall within one SD of the mean?
red on lab question (blue in quizlet image)
Lab2Q1: What type of graph/plot is this?
scatter plot
t-test formula
signal/static = difference/variability [This ratio is the t-statistic, and the value of this statistic is used to determine the p-value for your test.] looks at the ratio of the difference in group means to variability, in essence taking the ratio of the "signal" (the means) versus the "static" (the variance).
experiment
tests the validity of a hypothesis
Comparing Measures of Central Tendency If I have to describe the central tendency of a data set, which statistic should I use?
the mode is usually not representative of the central value in a data set, so it is rarely used in this capacity When deciding whether to use the median or mean, it often falls to a value judgment on your part New data set: 97, 93, 90, 88, 88, 85, 83, 82, 77, 75, 74, 71, 69, 66, difference between the median and the mean went from 2.1 points to 5 points with a change in only one grade. This shows the influence of "outliers" on means. means will be heavily influenced by outliers. Medians, which fall in the middle of the data set regardless of the magnitude of the largest and smallest values, will be less affected the median can also be unrepresentative of the central tendencies of a data set. While many students scored in the 90-100% range, there were many students with much lower scores, and the median doesn't give you any indication of that. At the same time, the mean value for this data set is 81.5, and yet not one of the 15 students scored even remotely close to this value on the exam the choice of the most appropriate statistic often depends upon the data set. What we really need is a statistic that gives us an indication of the data's "center", and another that describes the "spread" of the data around that value
Lab2Q7: The variance describes how far each value is from the mean. A measure of data dispersion in the same units as the mean, is obtained by taking the square root of the variance. This value is known as....?
the standard deviation
standard deviation
the standard deviation is useful because it allows us to examine the dispersion of a data set quickly and easily. Data that have a bell-shaped distribution when plotted, such as those shown in Figure 1, are said to have a "normal" distribution A normal distribution is symmetrical, with the majority of the points near the center (mean) and fewer as you progress away from the center we can conclude that about 68% of the data points will fall within one SD of the mean, 95% will fall within two SD's of the mean, and 99% will fall within three SD's of the mean ex: the SD = 10.8 points, so we can conclude that 68% of the scores fell between 69.0 and 90.6 points. convention dictates that you list the mean first, followed by the standard deviation in parentheses with a plus/minus sign. scores example would therefore be written as: mean (SD) = 79.8 (±10.8)
Types of Graphs
the two types that you will use most often in this course: bar graphs and line graphs If you can break your data into discrete groups like those shown here, then a bar graph is appropriate. Bar graphs are useful for graphing non-continuous data, such as data from different experimental groups If your data are continuous (each point is directly related to the next and can be connected by an infinite number of intermediate points), then a line graph is the way to go Line graphs are commonly used in scientific studies to present data when time (a continuous variable) is one of the variables involved. There is another type of graph worth mentioning - the scatter plot. In some cases you may need to graph two variables against one another to determine their relationship. Note that the points form an upward-sloping line, which indicates the two variables have a positive relationship to one another. Had the line sloped downward, this would suggest a negative relationship. If the points were scattered about and no clear relationship was visible, this would mean the two variables are unrelated to one another. The relationship can be indicated by drawing a "best-fit line" through the points.
Lab2Q6: what best describes the relationship of the two variables?
the two variables have a positive relationship
median
the value that occurs in the middle of the data set. examine the values in descending order and find the value in the exact middle of the data set
independent variable
the variable that is manipulated in an experiment
dependent variable
the variable that is measured in an experiment
Lab3Q1: Normal distribution are useful because they allow us to make statistical conclusion about the likelihood of occurence true or flase?
true
Tables
use descriptive statistics to summarize data sets examine the various methods available to visually present data a) Each table is numbered sequentially, b) title of the table should be descriptive. It should include both the dependent and independent c) cells in the table should be roughly equally spaced and the column and row headings should stand out against the data d) units for the data should always be identified, then enter data into the table during the experiment Compare the two ways to present this information - first as a table, and then in paragraph form. Because of this ability to organize information and present values, tables are widely used in scientific reports and articles to present data
Lab3Q3: Inferential statics are....?
used to infer whether two data sets are significantly different from one another
inferential statistics
used to make comparisons between data sets and infer whether the two data sets are significantly different from one another
mode
value that appears most frequently in your data set does not need to be near the center of the data set, it simply has to be the most common can have more than one mode if two or more values appear the same number of times
Outliers
values that fall well outside the range of the other values in the data set
Overshoot
when a population becomes larger than the environment's carrying capacity
Oceans cover a substantial part of our planet's surface, yet sometimes people who live further away from the oceans may forget about them altogether. It is a case of 'out of sight, out of mind' for many people. Nevertheless, humans are having a BIG impact on the world's oceans. To learn more about this impact, visit the website: Questions for review - Are we having an impact on the ocean? After all they are huge, covering 70% of the earths surface. https://incidentnews.noaa.gov/map
yes
