Evolution

Evolution 17: Evolution and Us

Students develop a presentation (comic, slideshow or video) to help scientists convince the public that learning about and understanding evolution is directly relevant to people’s lives. They shared these presentations within the classroom. Check out some of the presentations below!

Evolution 16: Manipulating Genes

Students search a collection of websites for information about one or more technologies that people have developed to affect traits of organisms. They summarize the key points from at least two sources and synthesize the information. They evaluate each source according to a set of criteria. Students share the results of their research with their peers. Finally, students consider the possible trade-offs of using these technologies.

Links about selective breeding and artificial selection

Where does seedless watermelon come from?

Fruit breeder hits the sweet spot with Cotton Candy grapes

U apple breeder is Minnesota's 'Captain crunch' - StarTribune.com

Heritage and Ancient Grain Project Feeds a Growing Demand | CALS

Cassava is Genetically Decaying, Putting Staple Crop at Risk | CALS

Creating Cooler Chickens for a Warming Earth - Modern Farmer

Breeding resistant chickens for improved food safety

Two of the world's top three insecticides harm bumblebees – study | Environment | The Guardian

The turning of wolves into dogs may have occurred twice | Science News for Students

Dog domestication happened just once, ancient DNA study suggests | Science News

Links about genetic modification and genetic engineering

GMO Basics | GMO Answers

The Truth about Genetically Modified Food - Scientific American

Genetically Modified Foods

Why genome editing offers a targeted way of breeding better crops

Pharming for Farmaceuticals

How did Roundup Ready and Roundup develop? | GMO Answers

Bt-Corn: What It Is and How It Works | Entomology

Why Roundup Ready Crops Have Lost their Allure - Science in the News

Farmers Say GMO Corn No Longer Resistant to Pests - Scientific American

Genetically Engineered Salmon Approved for Consumption - The New York Times

Genetically Modified Mosquito Sparks a Controversy in Florida - Yale E360

Good as Gold: Can Golden Rice and Other Biofortified Crops Prevent Malnutrition?

Evolution 15: Bacteria and Bugs: Evolution of Resistance

Students obtain information about four types of organisms that have evolved resistance to chemical control methods. Students identify the cause-and-effect relationship between human activity and the evolution of resistance to chemical controls, and they consider whether this pattern is likely to continue in the future. They conclude by using the principles of natural selection to explain the phenomenon of the evolution of antibiotic resistance.

Evolution 14: The Sixth Mass Extinction?

Students examine a graph showing rates of extinction over time and identify episodes where rates of extinction were well above the background rate of extinction. They match information on cards about the five major extinction events identified by scientists to the graph. They also summarize the possible causes for these extinctions. Students then read about rates of extinction since 1500 and examine possible causes for those extinctions. Students consider whether there is currently a sixth mass extinction due to humans and, if so, whether people should do anything to prevent it.

Bioprospecting

Learn more about how humans might be affected by extinction of species and loss of biodiversity.

Bioprospecting in Yellowstone National Park

Read about the growing scientific interest in bioprospecting and extremophiles in Yellowstone National Park.

Bioprospecting with the Leafcutter Ant

Read about how scientists are bioprospecting for novel antibiotic drugs with the leafcutter ant.

Evolution 11: Family Histories

Students draw and compare double bar graphs showing changes in the numbers of fossil families in the fish, reptile, and mammal classes over geologic time. From this evidence, they can conclude that both speciation and extinction have occurred in all classes of vertebrates for as long as each class has existed. Students discuss how this evidence provides further support for a branching model for evolution.

Evolution 10: Fossil Footprints

Students interpret fossilized footprint evidence that is presented to them in stages. Through this process, they develop their skills at distinguishing observations from inferences, and at modifying hypotheses in light of new evidence. They also learn about other kinds of evidence that can be gathered from fossils, such as behavior. The fossil footprint model is based on real dinosaur tracks from Dinosaur Ridge, outside Morrison, Colorado. 

Evolution 6: Mutations and Evolution

Students use a computer simulation to extend their investigation around the inheritance of the hemoglobin mutation. The simulation first extends their data from the previous activity through 30 generations. Then students are able to adjust the environmental conditions to see how access to resources and the prevalence of malaria influence the distribution of the hemoglobin gene over time. 

Evolution 5: Mutations: Good or Bad?

Students follow the inheritance of a hemoglobin mutation through two generations. Students identify patterns in their data and investigate the cause-and-effect relationship between environmental conditions and the frequency of a trait in a population. Based on their data collection and analysis, students construct explanations for how changes to a gene influence an organism’s ability to survive and reproduce. Specifically, students use the example of hemoglobin to explain how structural changes to genes (i.e., mutations), lead to changes in protein structure and function, and how this can lead to changes in the function of red blood cells which, in turn, can affect survival of individuals with the mutation.

Evolution 4: Battling Beaks

In this entertaining activity, the students simulated the effect of natural selection on an imaginary forkbird species. Genetic mutations, represented by tosses of a number cube, introduced variation into the population. They discover that mutations provide the variation on which natural selection acts. Some mutations cause traits that have the effect of enhancing an organism’s survival in its current environment. Students explain that individuals possessing these adaptive traits survive to have relatively more offspring. Thus, these traits become proportionally more common in the next generation. At the close of the activity, the class discussed the role of variation in the process of natural selection.

Evolution 3: A Meeting of Minds

In this activity, the students role-played an imaginary meeting between Charles Darwin, Jean-Baptiste Lamarck, a modern-day science reporter, and a middle school student. In the role play, Darwin and Lamarck engage in scientific argument as they present and compare their explanations for how a change in a species occurs. Students learn that Darwin’s explanation has been accepted as the Theory of Natural Selection and that this theory is essential to our understanding of evolution.The students learned that natural selection can be summarized as follows:

1. Variation within a species occurs naturally. (We now know this is due to genetic mutations occurring during chromosome replication.)

2. Organisms must compete for limited resources to survive.

3. The individuals that are better fit for current environmental conditions (due to their traits, which we now know are encoded at least in part in their genes) survive and reproduce more often than the others do (“survival of the fittest”).

4. As a result, the genes and traits that are most common in a population can change through time. 

Evolution 1: The Full Course

To begin the Evolution unit, students brainstormed questions to add to our Driving Question Board. They thought about the Unit Issue, "How are people affected by and affecting evolution??" and the Anchoring Phenomena, "Populations change over time. Some changes take place over very long time periods, while others take place over observable time periods. People can cause and be affected by these changes." Then students generated questions.  After sharing out their questions, they wrote the question they most want to answer on a sticky note. We then looked at the three driving questions for the Evolution Unit, and placed their questions near the driving question closest to their own. 

• How do populations change over time?

• What information can we learn from fossils?

• How are humans affecting evolution?

In this first activity, the students model the effects of antibiotics on a population of disease-causing bacteria during an infection. Students toss number cubes to determine whether an infected individual remembers to take the prescribed daily dose of antibiotics, which in turn affects the size and antibiotic resistance of the bacterial population in the patient. Students keep track of and graph the population size of the remaining bacteria depending on their resistance to antibiotics. Students consider the effect of changing the chemical environment on the survival of bacteria with varying levels of antibiotic resistance.