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In this article, we'll examine scientific ideas about the origin of life on Earth. The when of life's origins (3.53.53, point, 5 billion years ago or more) is well-supported by fossils and radiometric dating. But the how is much less understood. In comparison to the central dogma or the theory of evolution, hypotheses about life's origins are much more...hypothetical. No one is sure which hypothesis is correct - or if the correct hypothesis is still out there, waiting to be discovered.

This clicker case addresses several concepts related to the evolutionary ecology of herbivore defenses. A survey of several different studies that investigated chemical defenses in Thymus vulgaris (thyme) gives students the opportunity to develop hypotheses, pose potential experiments, and interpret data to develop a better understanding of not only herbivore deterrence, but also how natural selection can involve different pressures selecting for different phenotypes. The case study incorporates group discussion, analysis of experimental design, and data evaluation as central activities. It can be taught in a single 50-minute class session, an economy that is achieved in part by using a "flipped" approach. Students prepare outside of class by watching several short videos (one of which was made by the author) that teach the basics of herbivore deterrence and abiotic and biotic forces in the environment that can influence plant adaptations. The case study was designed for use in a large introductory-level class, but would also be appropriate for smaller classes or upper-level evolution courses.

Researchers have pinpointed a catalytic trigger for the onset of Alzheimer's disease - when the fundamental structure of a protein molecule changes to cause a chain reaction that leads to the death of neurons in the brain.

Sure, we know insufficient serotonin levels get a bad rap when it comes to depression, but that's like blaming one person in a full-scale riot. Depression isn't caused by only one factor. In fact, study co-author Elyse Aurbach says we're probably not getting to the core of why people are depressed because "the brain is immensely complex." In this study, the research team conducted eight experiments (four on animal brains, four on brains of the deceased human kind) of varying sample sizes - from 20 to 90 brains in each - and found that the brains of deceased humans who'd been depressed had increased levels of hippocampal FGF9 and that live animals with increased FGF9 levels demonstrated depressive, anxious behavior. "This is not just a correlation," study leader Huda Akil of the University of Michigan says. Less really may be more, at least when it comes to FGF9.

Taylor must write a report about a natural toxin while she is home from college on break. After a family dinner conversation about the latest attempt to poison a politician via a letter, Taylor decides to explore how ricin acts as a poison. Students work in small groups to help Taylor by working through figures from primary literature papers and exploring the use of an in vitro translation system, sucrose gradient fractionation and the effect of inhibiting various steps of translation.  A shorter, second day activity involves students looking further at the effect of ricin upon ribosome function and at the ricin protein itself.  Students individually complete a cumulative assignment of writing a letter back to Mom and Dad about how ricin has its effects. This case was designed for use in a second semester biochemistry course or a molecular biology course that incorporates the mechanism of transcription. Prerequisite knowledge includes a general understanding of the steps of translation and the ability to interpret data from agarose gels.

This clicker case study follows a dialogue between two college students, Lucy and Dan, as they discover how alternative splicing of mRNA molecules can allow a single gene to code for multiple proteins. Dan is participating in a clinical trial for a drug that may treat his migraines by inhibiting calcitonin gene-related peptide, and Lucy is working in a summer research lab that studies the protein calcitonin. They soon realize that the two proteins are both encoded by the same gene, and through their questioning and dialogue they come to understand the phenomenon of alternative splicing. They also learn about other steps of mRNA processing and about monoclonal antibodies. This case was designed to be taught in a flipped classroom, but could easily be adapted for a more traditional classroom setting if content covered in the pre-class videos is covered during the case study instead. It was designed for an introductory-level molecular biology course, but could be adapted for higher levels by including more information about the physiology and regulatory mechanisms involved.

At first, the researchers assumed that genes would shut down shortly after death, like the parts of a car that has run out of gas. What they found instead was that hundreds of genes ramped up. Although most of these genes upped their activity in the first 24 hours after the animals expired and then tapered off, in the fish some genes remained active 4 days after death.

Sometimes, a genetic tweak can make a really big difference in an animal's appearance. That's what likely happened when the predecessors of modern snakes lost their legs, a process that started some 150 million years ago, two separate groups of scientists have discovered. Although the teams took very different approaches to solve the mystery of how those limbs vanished, both came up with similar results: Mutations in DNA located near a gene key to limb formation keep that gene from ever turning on, they report today.

28 min video on DNA, RNA, protein

7 minute video summarizing translation, cartoon style

college website

3minute animation

3 minute video

3:30 min video emphasizing key molecules

Website with array of games and resources 

Venom - information on protein structure and function, following scenario of a scorpion bite.  Interactive game and activities included on site.

3:40 video A dynamic, 3-D, computer-animated video that takes you "inside" for a close-up look at how we're made. Watch as the mysteries of the Human Genome are literally "unraveled."

University of Vermont site with information on numerous genetic topics

7:00 video: This film is the first of a two part series on the evolution of new genetic information. Here we focus on Point Mutations - the simplest natural mechanisms known to increase the genetic information of a population. Our second film of the series will focus on duplication events - natural mutations that increase the total amount of genetic information of an individual. This film was produced under the guidance of molecular biologist Dr. Nicholas Casewell. http://www.lstmed.ac.uk/about/people/... Point mutations are small, natural edits in the DNA code of an individual. These edits can be passed from parent to child. Because they are mere edits, point mutations usually do not increase the total amount of information in an individual. As new information is gained, old information is lost. Point mutations do, however, increase the total amount of information within a population. In this film you will see several examples of beneficial point mutations which have enhanced a creatures abilities or even given rise to entirely new abilities. The first two examples were directly observed in bacteria by scientists in the lab. The third is a case found in domestic dogs, the last example was discovered in several species of wild animal.

The collection of proteins within a cell determines its health and function. Proteins are responsible for nearly every task of cellular life, including cell shape and inner organization, product manufacture and waste cleanup, and routine maintenance. Proteins also receive signals from outside the cell and mobilize intracellular response. They are the workhorse macromolecules of the cell and are as diverse as the functions they serve.