Group items tagged

Origins of Life Abiogenesis article in Wikipedia. The Origin of Life - Abiogenesis, a youtube video produced by Chuck Kopec.  A Simpler Origin for Life, an article by Robert Shapiro in Scientific American. The Miller-Urey Experiment article in Wikipedia. RNA and the RNA World Exploring the New RNA World, an essay by Thomas Cech published on the Nobel Prize website. RNA Video Clips from the HHMI website that include demonstrations of catalysis and interviews with Thomas Cech. A World Apart, an HHMI article about RNA World reseearch and the role of RNAs in medicine.  RNA World article in Wikipedia. Protocells The Emergence of Cells During the Origin of Life, an essay by Irene Chen published in Science.  What Came Before DNA? an article published in Discover featuring Jack Szostak and Steven Benner.  The Szostak Lab Astrobiology The National Astrobiology Institute, established by NASA to study life in the universe.  The SETI Institute, studying the origins, nature and prevalence of life in the universe.  Astrobiology: The Search for Life, a website hosted by the Exploratorium.

This case study focuses on the relationship between evolution and plasticity using a hands-on, inquiry-based approach. Students view examples from the literature that illustrate the difference between nature and nurture, or the relative contributions of genes and the environment in shaping phenotypes. Using the Trinidadian guppy system as an example, students learn about seminal work in the field in addition to exploring quantitative genetic techniques used to partition phenotypic variance between genes (G) and the environment (E). They use real data from one of the publications cited in the case to graph reaction norms illustrating GxE interactions at the family and population level. The inquiry-based approach means that students are introduced to new concepts in a stepwise fashion, and asked to develop and build their understanding using causal, explanatory evidence. The case concludes with an exercise in which students apply their knowledge to a real conservation problem in Trinidad and Tobago, where guppies are native. This case would be appropriate for an upper level biology, genetics, or evolution course.

Sheep ranching has destroyed habitat and decimated species in many areas of the world, but in Patagonia declining wool prices provide an opportunity to turn the tide. This case study places students in the role of advisor to an international NGO that has funds to advance conservation goals. A PowerPoint slideshow is used to present the Patagonian landscape, species, and variables that should be considered in conservation decisions.  After the presentation, students are given two maps: the first shows park boundaries, topography, roads, and major land forms; the second includes land prices overlaid on the first. Student groups are assigned a budget, and with the help of a set of guiding questions, students identify and defend a potential land purchase to develop as a protected area. The case is intended for use in an undergraduate class in conservation biology, environmental science or ecology, and presupposes another case in our collection, "The Great Patagonia Land Grab" by C.E. Quinn and J.E. Quinn

The Aedes aegypti mosquito is the major vector for transmission of numerous viral diseases, including yellow fever, dengue, and now, Zika. Interestingly, different subspecies of A. aegypti are known to exist in close proximity but with considerable genetic divergence between them. One major difference between a "forest" form and a "domestic" form is a strong preference in the latter subspecies for human over non-human blood biting. This difference was explored with genetic and neurophysiological approaches by a research group at Rockefeller University and published in a 2014 paper in Nature. This flipped case study uses parts of the Nature paper to focus on elements of the scientific method as well as evolutionary questions raised by the difference in biting preference between the two subspecies. Students prepare for class by watching a video that provides background information about the published study that forms the basis for the case. In class students then work in groups to develop a hypothesis, predictions and proposed experiments to test the idea of different biting preferences.

This 5 lesson unit, which was designed by teachers in conjunction with scientists, ethicists, and curriculum developers, explores the scientific and ethical issues involved in stem cell research. The unit begins with an exploration of planaria as a model organism for stem cell research. Next, students identify stages in the development of human embryos and compare the types and potency of stem cells. Students learn about a variety of techniques used for obtaining stem cells and the scientific and ethical implications of those techniques. While exploring the ethics of stem cell research, students will develop an awareness of the many shades of gray that exist among positions of stakeholders in the debate. Students will be provided an opportunity to become familiar with policies and regulations for stem cell research that are currently in place in the United States, the issues regarding private and public funding, and the implications for treatment of disease and advancement of scientific knowledge. The unit culminates with students developing a position on embryonic stem cell research through the use of a Decision-Making Framework. Two culminating assessments are offered: In the individual assessment, students write a letter to the President or the President's Bioethics Committee describing their position and recommendations; In the group assessment, students develop a proposal for NIH funding to research treatment for a chosen disease using either embryonic or 'adult' stem cells.

Paul Andersen describes the major mutations found in the living world. He starts with an analogy comparing the information in DNA with the information in a recipe. Changes in the DNA can result in changes to the protein, like changes in the recipe can result in changes in the food. He describes the three major point mutations; substitutions, deletions and insertions. He also describes several chromosomal mutations.

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.

In July, the AP reported that its first round of tests showed disease-causing viruses directly linked to human sewage at levels up to 1.7 million times what would be considered highly alarming in the U.S. or Europe. Experts said athletes were competing in the viral equivalent of raw sewage and exposure to dangerous health risks almost certain. The results sent shockwaves through the global athletic community, with sports officials pledging to do their own viral testing to ensure the waters were safe for competition in next year's games. Those promises took on further urgency in August, after pre-Olympic rowing and sailing events in Rio led to illnesses among athletes nearly double the acceptable limit in the U.S. for swimmers in recreational waters.

More than 400 scientists, bioethicists, and historians from 20 countries on 6 continents have gathered this week in Washington, DC, for the Human Gene Editing Summit. The attendees are a veritable who's who of genome editing: Jennifer Doudna of the University of California, Berkeley, Emmanuelle Charpentier of Max Planck Institute for Infection Biology, and Feng Zhang of the Broad Institute of MIT and Harvard-the three discoverers of the CRISPR-Cas9 system's utility in gene editing-plus dozens of other big names in genome science. Cal Tech's David Baltimore along with the heads of the four national societies hosting the meeting (US National Academy of Sciences, US National Academy of Medicine, Chinese Academy of Sciences, and the U.K.'s Royal Society) provided opening remarks on Tuesday (December 1). And as I sat stage right in the NAS auditorium, I noticed the unmistakable rear profile of Harvard Medical School's George Church three rows in front of me. Church was scheduled to speak at a session later that afternoon about the application of CRISPR and other new precision gene editing techniques to the human germline-a hot-button topic since April, when a Chinese group published it had successfully modified the genomes of human embryos, and the National Institutes of Health (NIH) said it would not fund such research. Then in September, the U.S./U.K.-based Hinxton Group, an international consortium of scientists, policy experts, and bioethicists, said it supported the use of genetic editing in human embryos for limited applications in research and medicine.  

This case study introduces students to the complex field of immunology and the wide variety of host-pathogen interactions that drive evolutionary change.  The case begins with a basic overview of the phases of the immune response and how each contributes to host defense against an invading pathogen.  In order to delve deeper into each phase, students explore the metaphor of a battle in which a host and pathogen are locked in combat in order to understand the individual components of the immune response.  Once students successfully understand how the immune system works in general, they are then asked to think creatively about how a pathogen that wants to survive could evolve to evade the immune response, and to find concrete examples in the literature.  The overall goal is for students to gain a deeper understanding of the immune response and how host-pathogen interactions drive coevolution of both host immune components and the pathogen itself. The case was originally designed for an introductory biology course, but can easily be adapted for use in a variety of different courses and levels.

This case study tells the story of a group of ten men, recently released from federal penitentiaries, who are housed in a residential reentry center for the remainder of their sentences. Their stay is intended to bridge the gap between incarceration and return to life in the community. Due to the length of time served, the men are poorly skilled in healthy behaviors and self-reliance in the areas of food and activity. Although a work of fiction, the narrative realistically portrays a variety of challenges that the men face including a chronic health issue, menu planning, tight budgets, hunger, boredom, lack of cooking skills, and life without a local supermarket. Innovation, trial and error, and collaboration result in a story of resilience and health behavior change in a sparsely populated area of Northern Michigan. The case was originally developed for a college-level nutrition course, but could also be used in social work, community health, and health education, nursing, and dietetics classes.

In this interrupted case study developed for use in a flipped classroom, students read about a picnic that takes place in autumn during the peak of fall color and along the way learn about light absorption by photosynthetic pigments, why leaves turn color in the fall, atmospheric CO2 concentrations and their effect on photosynthesis, and the C3, C4, and CAM photosynthetic pathways. The case is designed to provide introductory biology students with a basic understanding of photosynthetic pathways and how environmental factors affect plants using these pathways. The activity could also be used in an advanced high school biology course covering photosynthesis. The case includes several short videos that students watch as homework before coming to class so that they are prepared to work together in class in small groups to answer the case questions.

This PowerPoint-driven, flipped case study begins with a short video about a woman suffering from cystic fibrosis (CF) in the 1970s, a friend of the lead author's, whom she met in college and who died in her twenties. Hooked by this personal story, students then delve into the genetics and biology of cystic fibrosis as they learn about the difference between dominant and recessive genes, make Punnett squares that depict various types of inheritance, distinguish between probability and actual numbers, differentiate types of mutations, and learn about the opportunistic infections that CF patients often succumb to.  Students conclude the case by watching two additional videos on chest compression machines and the contemporary life expectancy of patients with CF.  In addition to the scientific content presented in the case, it is hoped that students will empathize with, and be motivated by, the young people presented in the videos as they struggle with a very real, incurable disease deeply rooted in genetics.

The life science/biology course is divided into 12 instructional segments grouped into four sections. In the first section, From Molecules to Organisms: Structures and Processes, students develop models of how molecules combine to build cells and organisms (IS1 [Structure and Function]; IS2 [Growth and Development of Organisms]; IS3 [Organization for Matter and Energy Flow in Organisms]). In the second section, Ecosystems: Interactions, Energy, and Dynamics, students zoom out to the macroscopic scale to show how organisms interact (IS4 [Interdependent Relationships in Ecosystems]; IS5 [Cycles of Matter and Energy Transfer in Ecosystems]; IS6 [Ecosystem Dynamics, Functioning, and Resilience]; IS7 [Social Interactions and Group Behavior]). Students return to the role that DNA plays in inheritance during the third section, Heredity: Inheritance and Variation of Traits (IS8 [Inheritance of Traits]; IS9 [Variation of Traits]). The class ends tying together interactions at all these scales by explaining evolution and natural selection in Biological Evolution: Unity and Diversity (IS10 [Evidence of Common Ancestry and Diversity]; IS11 [Natural Selection]; IS12 [Adaptation and Biodiversity]). A vignette in IS12 illustrates the level of three-dimensional understanding students are expected to exhibit as a capstone of the course.

Problem-based learning (PBL) is an exciting way to learn biology and is readily incorporated into large classes in a lecture hall environment. PBL engages students in solving authentic biological case problems, stimulating discussion among students and reinforcing learning. A problem-based learning environment emulates the workplace and develops self-directed learners. This is preferable to a mimetic learning environment in which students only watch, memorize, and repeat what they have been told. The examples given here are suitable for use in a first year college biology lecture theater, but the method is applicable to any class size and educational level. [A more detailed explanation of PBL in Biology may be found in Chapter Four of INSPIRING STUDENTS, published in 1999 by Kogan Page.]

This case study synthesizes students' knowledge of the central dogma and cell structure by examining a rare health disorder in order to understand protein targeting and its medical consequences. Students first identify the molecular alteration in affected members of a family with renal Fanconi syndrome as reported in the New England Journal of Medicine (2014). Students then use an online bioinformatics tool to analyze the wildtype and mutant proteins and examine their subcellular localization. Finally, students use this information to explain the symptoms of affected family members. The case is delivered with a PowerPoint presentation that includes a selection of brainstorming prompts and "clicker questions." Students complete a worksheet (included in the teaching notes) before class, making the activity suitable for a flipped classroom. A second worksheet (also included in the teaching notes) is completed during class. The case is written for an introductory biology course for majors, but could also be used as a unit capstone in a non-majors human biology course; the case is also scalable to upper division courses in physiology that specifically explore kidney function.

This interrupted case study, designed for an introductory biology or environmental science course, introduces students to the complexity of ecosystems by examining changes in trophic interactions and abiotic factors in a freshwater ecosystem as a result of human actions. The case narrative describes the recent and undesirable appearance of decomposing algae (Cladophora glomerata) on a public beach in the Laurentian Great Lakes. Students are asked to use the scientific method by creating hypotheses and examining observational data to describe biotic and abiotic components of the Great Lakes ecosystem. The case requires students to differentiate between benthic and pelagic environments (e.g., the influence of depth and phytoplankton density on light availability, and the availability of phosphorus) and the interactions between organisms in both environments. Students also examine shifts in these interactions as a result of the newly introduced zebra and quagga mussels, which have ultimately resulted in the algae's presence on the beach. There are also opportunities to discuss the impact of these ecosystem changes on people who own property and/or visit the beach.

This case study examines the molecular methods that were used to reverse engineer the 1918 influenza virus strain in order to try and solve the mystery of why it was so deadly. The story starts in the 1950s with the unsuccessful attempts to culture the influenza virus and follows scientists through to the turn of the century when cutting edge molecular tools enabled scientists to finally resurrect the 1918 virus through reverse genetics. The history and methods involved in resurrecting this deadly virus are reviewed in class with a PowerPoint presentation containing clicker questions (answered with a personal response system) and discussion questions (answered in small groups). This "clicker case" is suitable for high school biology and lower division undergraduate biology classes for non-majors. It could also be used in any lower division non-major class focused on human disease and the history of human disease.

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.

In this interrupted case study students analyze the complexities surrounding identification and confirmation of cancer clusters. The case challenges students to consider the evidence from two different perspectives; a local family physician representing the community, and a cluster investigation officer who has worked on several cancer cluster investigations. This case was inspired by the discussion about a possible cancer cluster in Clyde, Ohio, where around 20 cases of childhood cancer since 2001 fueled public concern, leading to an investigation by the Ohio department of health in 2006. This case was designed for introductory courses in biology and environmental sciences, taken by both science majors and non-science majors. In addition to introductory college classes, this case could also be used in advanced high school biology classes.