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This activity guides the analysis of a published scientific figure from a study that modeled the impact of an infectious fungal disease on a bat population. In 2006, a disease called white-nose syndrome (WNS) began wiping out bat populations in North America. Because many of these bats eat insect pests, the spread of WNS may devastate ecosystems and increase pest control costs. In this study, scientists mathematically modeled the effects of WNS to estimate extinction probabilities for the little brown bat (Myotis lucifugus) population in the northeastern United States. This figure shows these probabilities projected for five annual rates of population decline. Each projection is simulated up to 100 years after WNS emerged in the population. The "Educator Materials" document includes a captioned figure, background information, graph interpretation, and discussion questions. The "Student Handout" includes a captioned figure and background information.

For the first time in modern history, the world's population is expected to virtually stop growing by the end of this century, due in large part to falling global fertility rates, according to a Pew Research Center analysis of new data from the United Nations. By 2100, the world's population is projected to reach approximately 10.9 billion, with annual growth of less than 0.1% - a steep decline from the current rate. Between 1950 and today, the world's population grew between 1% and 2% each year, with the number of people rising from 2.5 billion to more than 7.7 billion.

This interrupted case study introduces basic modeling to investigate a decline in an American marten population on an island in Southeast Alaska. Two summer field technicians working on a long-term field ecology project for one of their professors notice that there are fewer marten captures this year. Through discussions with their professor, conversations with a local fur trapper, and based on their own observations, they develop a plan to model the population and the potential causes of the decline to solve the mystery. Students use Excel or other database software along with life tables and introductory population ecology to investigate three potential causes of the marten population decline. This case was developed for use in an environmental science or wildlife management course but could also be used in an advanced science high school course or general ecology course. It would be beneficial for students to have some background in statistics including how to interpret R-squared values, p-values, and 95% confidence intervals.

Gene flow is the transfer of genetic material between separate populations. Many organisms are divided into separate populations that have restricted contact with each other, possibly leading to reproductive isolation. Many things can fragment a species into a collection of isolated populations. For example, a treacherous mountain pass may cut off one herd of mountain goats from another. In human beings, cultural differences as well as geographic separation maintain unique populations: It is more likely that a person will marry and have children with someone who lives nearby and speaks the same language.

In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies (the proportion of members carrying a particular variant of a gene). Immigration may also result in the addition of new genetic variants to the established gene pool of a particular species or population.

Population statistics are like crystal balls -- when examined closely, they can help predict a country's future (and give important clues about the past). Kim Preshoff explains how using a visual tool called a population pyramid helps policymakers and social scientists make sense of the statistics, using three different countries' pyramids as examples.

This hands-on activity, used in conjunction with the film The Making of the Fittest: Natural Selection in Humans, teaches students about population genetics, the Hardy-Weinberg principle, and how natural selection alters the frequency distribution of heritable traits. It uses simple simulations to illustrate these complex concepts and includes exercises such as calculating allele and genotype frequencies, graphing and interpretation of data, and designing experiments to reinforce key concepts in population genetics.

This interactive case discussion was created to emphasize the clinical relevance of population genetics, but is also a suitable resource for teaching the basic principles of population genetics while relating them to human genetic variation. Our understanding of human genetic variation has deepened over the past decade due to fine-scale genome mapping. Applying this knowledge to the evaluation of ancestry-based genetic testing strategies, such as direct-to-consumer genetic testing, is an important component of the practice of culturally-competent medicine and a relevant way to teach the foundations of population genetics, including Hardy-Weinberg equilibrium.

Genetic studies of human disease are more challenging to perform in sub-Saharan Africa because genetic diversity is greater than in other populations. This pilot will increase our understanding of African genome variation and enable the design of large-scale genetic association studies in the region. Studies into the genetic basis of disease in European populations have made major advances in the past few years, yet similar studies in sub-Saharan Africa have been slower to develop. The high level of genetic diversity that exists in populations from sub-Saharan Africa makes genetic associations with disease more difficult to identify. The African Genome Variation Project aims to collect essential information about the structure of African genomes to provide a basic framework for genetic disease studies in Africa.

The following six lessons enable students to use different features of the site to explore trends in population, the environment, and human well-being over the past 2,000 years, as well as projections of future growth. The lessons are designed for high school science and social studies classrooms and address current national and state standards, as well as content for several Advanced Placement (AP) courses. Links to standards and AP course outlines are available in a searchable database.

"This modular case study tells the story of Dan and Annie, a married couple of Acadian ancestry who have a genetic form of deafblindness called Usher syndrome. They live in Southwest Louisiana, home of the largest population of DeafBlind citizens in the United States. Acadian Usher syndrome is caused by an allele of the USH1C gene that came to Louisiana with the first Acadian settlers from Canada who founded today's Cajun population. This allele's single nucleotide substitution creates an erroneous splice site that produces a defective cytoskeletal protein (harmonin) of the cochlear and vestibular hair cells and retinal photoreceptors. This splice site is the target of a promising gene therapy. The case study applies and connects Mendelian inheritance, chromosomes, cell division, vision and hearing, DNA sequences, gene expression, gene therapy and population genetics to a specific gene and its movement through generations of Dan and Annie's families.  After the introduction, each of the remaining sections can be used independently either for in-class team activities or out-of-class extensions or assignments over an entire year of introductory undergraduate biology. "

Students can manipulate mutations in bunnies, such as fur color and teeth length. By altering the environmental factors, students can see how the bunny populations change over time. For example, in a warm environment, more bunnies will have brown fur, but in the cold environment, more bunnies will have white fur. The student worksheet includes instructions on how the simulator works. Then students perform a variety of "experiments" to explore mutations in the populations. I include this as part of a unit on evolution, so students are familiar with VIDA charts. Students complete a chart at the end of the activity to summarize how variations in populations lead to adaptation.

Simulators which display cummulative generation graphs for variables.  Very cool data rich resource!  Includes Carbon cycle, demographis (human populations), Disease transmission, ecology, and energy simulations.

Five distinct humpback whale populations have been identified across the North Pacific Ocean in the most comprehensive genetic study of the mammals in this region yet, a new study reports.

2 min video on human population growth

Before civilization began to impact the human life cycle approximately 10,000 years ago, human beings had high birth and death rates. Today the world is in the midst of a demographic transition - a transition to low birth and death rates - as the ability to control both disease and reproduction increases. Along the way, between these extremes, populations go through an intermediate period of continued high birth rates, combined with low death rates, resulting in a population explosion.

Biologists have long puzzled about how evolutionary selection, known for its ruthless requirement for efficiency, allows the existence of males - when in so many species their only contribution to reproduction are spermatozoa. But research published today in Nature shows that sexual selection - when males compete and females choose over reproduction - improves population health and protects against extinction, even in the face of genetic stress from high levels of inbreeding.

Although Hardy-Weinberg equilibrium is a fundamental part of introductory biology classes, students often have difficulty understanding its implications. This interrupted case study places students in the role of small teams who are conducting preliminary research into the impact of roads on the population structure of timber rattlesnakes in order to apply for a grant for further research. Research groups consisting of 3-4 students work through a series of questions allowing them to use HWE principles to discover for themselves how deviations from HWE can have implications for conservation biology. Periodic interruptions with help sheets (see Supplemental Materials) allow teachers to maintain an active role in the students' progress, while also demonstrating the collaborative nature of scientific research. Ultimately students formulate formal emails summarizing and interpreting their findings in order to "apply" for the grant. The case is designed for undergraduate students in introductory biology or in lower-level population genetics/conservation courses where connecting basic genetic principles to ecology and sustainability is key.

Six years ago, Yale University's Stephen Stearns and colleagues took advantage of a long-running study in Framingham, Massachusetts, to assess whether the effects of natural selection could be discerned among the people in the multigenerational study population. Over the last seven decades, public-health researchers have been monitoring the residents of Framingham, noting their vital statistics as well as blood sugar and cholesterol levels to understand the factors that lead to heart disease. As the initial group of research subjects got older, the study started to include their children, and then their grandchildren. The records provide a unique view of the health of a segment of the American population since 1948.

The short film opens with two questions: "So what determines how many species live in a given place? Or how many individuals of the species can live somewhere?" The research that provided answers to these questions was set in motion by key experiments by ecologists Robert Paine and James Estes. Robert Paine's starfish exclusion experiments on the coast of Washington state showed that removing starfish from this marine ecosystem has a big impact on the population sizes of other species, establishing the starfish as a keystone species. James Estes and colleague John Palmisano discovered that the kelp forest ecosystems of the North Pacific are regulated by the presence or absence of sea otters, which feed on sea urchins that consume kelp. These direct and indirect effects of sea otters on other species describe a trophic cascade. These early studies were the inspiration for hundreds of investigations on other keystone species and trophic cascades, as well as ongoing studies into the regulation of population sizes and species numbers.