The concept of interdependence in an ecosystem and its effect on the evolution of populations is further explored through a model of a dam. Students build a dam in the middle of the field, dividing the ecosystem in half to illustrate the effects of geographic isolation. They watch as the grass and then the rabbit populations in that region shift to one variant in the population. When students remove the dam, they observe the ecosystem slowly return to its original state. (Evolution Activity 8 of 10.)

In this activity, students review inheritance with variation. A Virtual Field model has light levels that vary smoothly from top to bottom. A single type of seed grows best in the center of the field, but the model includes variation in the offspring seeds. Since each plant scatters seeds randomly, it happens occasionally that some of these different seeds fall in a location where the light level is just right for it. When this happens the seed will grow into a healthy plant that will produce seeds of its own. In this way, the single type of plant eventually evolves into a full spectrum of different varieties. (Evolution Activity 3 of 10.)

This activity uses a model of the Virtual Ecosystem with three species in it: grass, rabbits, and hawks, enabling the students to explore the effect of predation on the prey population. At first students explore protective coloration as they 'become' a hawk and try to catch and eat brown and white rabbits on a snowy field. The latter blend into the background and are harder to see, so they have a selective advantage. Students then explore how the color of the rabbit population changes as the environment changes over time. (Evolution Activity 9 of 10.)

This transfer activity tests student understanding of variation and inheritance. It starts with five flower boxes, as in 'The Virtual Greenhouse,' and three types of seeds with variations in their roots. The flower boxes differ in the amount of water they receive, and students discover which seeds thrive in which environment. Students are then challenged to produce a crop of plants that can grow everywhere in a field by taking advantage of the small variation in root type from one generation to the next. (Evolution Activity 5 of 10.)

The goal of this activity is to introduce students to how variation in organisms can enable them to live in different environments. For example, plants with different sizes of leaves are adapted to grow under different amounts of light. Students plant three different types of seeds in five different flower boxes and are challenged to determine the light level under which each type of seed grows best. (Evolution Activity 1 of 10.)

Students discover that variation in plants allows some varieties to survive in near-drought conditions. Next, students learn that different types of rabbits prefer to eat different varieties of plants. Students make the connection between rainfall amount and the rabbit population's ability to survive by thinking first about rainfall and plants, then about plants and rabbits. Students discover that when certain plants cannot grow and reproduce, the rabbits that eat those plants will not have enough food to survive. (Evolution Activity 7 of 10.)

In common experience, the term "adapting" usually refers to changes during an organism's lifetime. In contrast, evolutionary biologists use the term "adaptation" to refer to a heritable trait that increases fitness. To help students reconcile these different concepts, this activity introduces the concept of phenotypic plasticity (the ability of an organism to adapt to different environments within its lifetime). Questions guide students in analyzing how the balance between the advantages and disadvantages of a characteristic (e.g. an animal's color) can vary in different circumstances, how phenotypic plasticity can be a heritable trait that can optimize fitness in a variable environment, and how natural selection can influence the amount of phenotypic plasticity in a population. This activity is designed to help high school students meet the Next Generation Science Standards and the Common Core State Standards.

In this online activity, learners discover how random variation influences biological evolution. Biological evolution is often thought of as a process by which adaptation is generated through selection.Œć While it is recognized that random variation underlies the process, emphasis is usually placed on selection and resulting adaptation, leaving a sense that it is selection that drives evolution.Œć This simulation highlights the creative role of random variation, offering a somewhat different perspective: that of evolution as open-ended exploration driven by randomness and constrained by selection, with adaptation as a dynamic, transient consequence rather than an objective.

Students develop their understanding of natural selection by analyzing specific examples and carrying out a simulation. The questions in the first section introduce students to the basic process of natural selection, including key concepts and vocabulary. The second section includes a simulation activity, data analysis, and questions to deepen students' understanding of natural selection, including the conditions that are required for natural selection to occur. In the third section, students interpret evidence concerning natural selection in the peppered moth and answer questions to consolidate a scientifically accurate understanding of the process of natural selection, including the role of changes in allele frequency. This activity is aligned with the Next Generation Science Standards.

Racism began to evolve during the second half of the 17th Century, around 1640.  African Americans made up a few thousand of the total population in the new colonies. Many of those early African Americans experienced life much like their fellow European settlers. The reversals they experienced were subtle at first but then became drastic. Those changes occurred because slavery was being used in the Caribbean to produce sugar so those ideas about labor traveled north easily.  It was also harder to import labor from Europe because the Civil War and the plague had reduced the population there. European colonists were realizing that enslaving African Americans would be more efficient and profitable. 

As technology has evolved over time so has the understanding of the structure of the atom. This module focuses on how the model of the atom has changed over time using The Atomic Theory Timeline including the historical contributions of the scientists involved. This module was developed by Tracey Nipper as part of a Virginia Commonwealth University STEM initiative sponsored by the Virginia Department of Education.

The student will use the poetry of Phillis Wheatley, Jacqueline Woodson, Countee Cullen, and Amanda Gorman to draw conclusions about the historic eras in which they wrote.

Third of three lessons on the changing European borders, students learn about diffusion of the Black Death. The spread of the Black Death illustrates interaction as people, goods, and ideas move through both time and space. The Black Death decimated the population of Europe in the 1300s. Key questions: Where did the Black Death originate? How did the Black Death arrive in Europe? How did the Black Death affect life in Europe?

First of three lessons examine changing European borders, students compare maps illustrating changes of Europe's division of territory from 1000 A.D. (C.E.) to 1450 A.D. (C.E.). Unification of smaller regions into a larger state may form the basis for political power and the ability to exert influence over other countries. Students uncover the relationship between territorial extent and political power. Key questions: How did the consolidation of territory affect the formation of nation states?; How could stable borders contribute to the political stability of a state?

Second of three lessons on changing European borders, students determine the general routes and time span of the Crusades through maps depicting their routes. Includes primary sources to support comparison of the accounts of the Crusader victory in capturing Jerusalem in 1099. Concludes with an evaluation of crusades' success. Key questions: What areas were involved in the Crusades? What areas did the Crusader states seek to control? What role did the Byzantine church play in the Crusades and how they affected the Byzantines? How did the establishment of Crusader states influence the fall of Constantinople?

No sitting American president traveled outside the country before Theodore Roosevelt traveled to Panama in 1906 to see the construction of the Panama Canal. A century later Air Force One regularly carries the head of the executive branch to all corners of the world. The Executive Abroad maps the international trips of presidents and secretaries of state.