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Taxonomy is the study of scientific classification, in particular the classification of living organisms according to their natural relationships. Taxonomy's first father was the philosopher Aristotle (384-322 BC), sometimes called the "father of science." It was Aristotle who first introduced the two key concepts of taxonomy as we practice it today: classification of oranisms by type and binomial definition.

Early classification systems probably grouped organisms as to whether they were beneficial or harmful. Another ancient classification system recognized 5 animal groups - domestic animals, wild animals, creeping animals, flying animals, and sea animals.

This case study teaches students about allopatric speciation through an investigation of the benthic and limnetic sticklebacks of Paxton Lake, which are among the youngest species on Earth, diverging from each other after the Pleistocene glaciers melted and the Gulf Islands formed. Researchers at the University of British Columbia have carried out a variety of fascinating studies on these hardy little fish. Results from this research (formatted as data sheets included in the teaching notes) are provided to students who design experiments and then compare actual data to investigate why benthic and limnetic sticklebacks seldom interbreed in Paxton Lake. Developed for a first-year biology course for majors organized around the general theme of evolution and the history of life on Earth, this case study is an updated version of another case in the collection, "Something's Fishy in Paxton Lake" (Sharp, 2001). The current version is especially suited for a flipped classroom in which students prepare for class ahead of time with a reading assignment that also involves the viewing of a video by the case authors that introduces the mechanisms of allopatric speciation.

Scientists and healthcare professionals initially exhibited little concern over the Zika virus even after evidence of human infection was first identified in 1952; Zika appeared to be both rare and unassociated with morbidity or mortality. Around 2015 all of this changed as journalists, scientists, public health officials, and laypeople scrambled to learn about its varied modes of transmission and devastating consequences (e.g., birth defects and autoimmune disorders). Although research continues to rapidly evolve, this case study directs students to reliable scientific sources (e.g., Centers for Disease Control and World Health Organization) that will likely continue to provide the most current information in order to explore questions such as: Where did the virus come from? How does it spread? What can we do to prevent it? Students will also consider the public health challenges and possible solutions associated with emerging infectious diseases. The case was originally written for an upper-level biology or public health course in which students already have some basic background knowledge regarding viruses, vaccines, and infectious disease.

When it's completely unraveled, DNA is known to extend approximately six feet in length, yet is somehow able to cram itself into a cell's nucleus. In a study published today (July 27) in Science, researchers created a novel visualization method that revealed a 3-D glimpse of chromatin as it sits jam-packed within the nuclei of human cells. The researchers found that, contrary to how it's depicted in most textbooks, chromatin does not fold in on itself in an organized manner to create distinct structures. Instead, it forms a pliable, inconsistent chain characterized by a wide variety of folding patterns. 

This flipped case was designed to introduce students in a general introductory biology course to basic protein structure. The two videos and interrupted case use keratins in hair as model proteins. From the videos students learn how amino acids regulate protein structure, and how small changes in amino acid sequence have large impacts on overall protein organization and function. The case story focuses on a puppy whose hair changes from straight to curly when it sheds its coat. The protagonist tests the adult versus puppy hair, and discovers that the amino acid composition is different in the curly versus straight hair samples. Students apply basic principles of protein structure to hypothesize why the dog's coat switched from straight to curly. The case intentionally stops short of providing a complete answer to the mystery, so students think through the molecular processes logically rather than having a final "correct" answer. An optional activity is provided that makes the case more appropriate for an introductory cell biology class.

"This case study introduces students to Duchenne muscular dystrophy (DMD) and its underlying genetics, cell biology, and some of the associated biochemical pathways.  DMD is an X-linked disorder characterized by progressive muscle weakness and wasting due to the absence of a protein called dystrophin, which in turn causes degeneration of skeletal and cardiac muscle. There is currently no established cure for this disease.  The case follows the progress of "Casey," an undergraduate student who has just declared her biology major and is interested in expanding her scientific understanding of the different fields of biology. The case is organized in three parts: genetics, cell biology, and biochemistry, each exploring DMD through its unique lens. Throughout the case, Casey is presented with multiple outlets of information, including class lectures, direct e-mail interaction with a professor, scientific journals and websites, from which she (and any student engaged with the case) gathers knowledge about DMD."

A common misconception is that Darwin suggested that something as complex as the eye could not have evolved through natural selection. While the misunderstanding often comes from an incomplete reading of his argument, we have long known that intermediate varieties of eyes (e.g., eyespots, cupped eyes, and complex camera-type eyes) exist in a variety of organisms. Eyes are so common that it was thought that they had evolved independently 40-60 times. More recent molecular work, however, has identified the role of Pax6 genes and their homologs in the formation of eyes during development. The basic information for eye formation appears to have been present in the common ancestor to all bilaterans, and perhaps may be more ancient than that. This interrupted case study examines the history of evidence for eye evolution from Darwin's initial postulates, through evidence of multiple intermediate forms, concluding in an examination of Pax6 homologs. The case is primarily for an introductory biology class but an additional section would be appropriate for upper-level evolution or developmental biology courses.

This index organizes teaching resources by topic-related issue and provides teaching resources (case studies, problems, videos, articles, activities, and other resources) which can be used to to facilitate the teaching of introductory non-majors biology using Problem or Case Studies Based Learning.

The article "The difference makers" (10.9 readability score) gives an overview of transposons, or "jumping genes," and how these bits of genetic material have affected genetic variety and evolution in humans and other organisms. Students can focus on details reported in the article, follow connections to earlier articles about transposons and human evolution, explore crosscurricular connections to other major science topics, and construct a phylogenetic tree of primate evolution based on the locations of retroviral sequence insertions in chromosome 21

Behold the microscopic jungle in and around you: tiny organisms living on your cheeks, under your sofa and in the soil in your backyard. We have an adversarial relationship with these microbes -- we sanitize, exterminate and disinfect them -- but according to microbiologist Anne Madden, they're sources of new technologies and medicines waiting to be discovered. These microscopic alchemists aren't gross, Madden says -- they're the future.

Imagine you swallowed a small bird and suddenly gained the ability to fly … or you ate a cobra and were able to spit poisonous venom! Well, throughout the history of life (and specifically during the evolution of complex eukaryotic cells) things like this happened all the time. Adam Jacobson explains endosymbiosis, a type of symbiosis in which one symbiotic organism lives inside another.

Their nervous systems have changed over time to fight off the powerful chemicals-an extraordinary example of evolution in action, according to a new study. "I've been wanting to understand how organisms could acquire neurotoxins, [which] requires an animal to reorganize their nervous system," says study coauthor Rebecca Tarvin, a biologist at the University of Texas at Austin and National Geographic Society grantee.

Hilary Brown is a PhD student, working in the infection genomics group at the Wellcome Trust Sanger Institute. In this film he describes how to work safely in the lab with bacteria from the human gut including culturing them on agar plates and extracting the DNA for genome sequencing. The infection genomics programme uses a variety of different research approaches to study the biology and evolution of disease-causing organisms such as viruses, bacteria and parasites and understand how they cause disease in humans and other animals.

Across the planet, humans eat on average between 1 and 2.7 kilograms of food a day, and every last scrap makes its way through the digestive system. Comprised of ten organs covering nine meters, this is one of the most complicated systems in the body. Emma Bryce explains how the different parts of the digestive system work to transform your food into the nutrients and energy that keep you alive.

When it comes to what you bite, chew and swallow, your choices have a direct and long-lasting effect on the most powerful organ in your body: your brain. So which foods cause you to feel so tired after lunch? Or so restless at night? Mia Nacamulli takes you into the brain to find out.

But if Gánti's theories had been more widely known during the communist era, he might now be acclaimed as one of the most innovative biologists of the 20th century. That's because he devised a model of the simplest possible living organism, which he called the chemoton, that points to an exciting explanation for how life on Earth began.

The activity begins with students observing different organisms or phenomena and developing questions based on their observations. They then sort their questions into those that can and cannot be answered using the methods of science. Students practice writing scientific questions, designing experiments to address scientific questions, developing questions that involve cause and effect, and understanding the importance of cause and effect questions in scientific research. At the end of the activity, students determine the research questions being asked from reading journal article titles and parts of a published paper or other reported results. Several possible extension activities are provided for continuing the investigation and research of phenomena.

The data comes from the open Tree of Life Project, a collaboration among biologists and other scientists around the world. It contains decades' worth of work in phylogeny, evolutionary history of and relationships among groups of organisms. The project is about a year away from a complete tree of all life, Rosindell said. He wanted a system in place that could visualize it as soon as it's ready. Right now, OneZoom only contains mammals, but that's still more than 5,000 species, all correlated with each other and color-coded according to their threat levels. Rosindell has big plans for the rest, and he even wants to build a searchable app for smartphones, showcasing the history and relationships between all life on Earth.

From single-celled organisms to giant redwoods, Life Science explores all of Earth's life forms. Use interactive, animated activities to identify the living and nonliving components of an ecosystem, design a Venn diagram to compare the migrations of monarch butterflies and red knot shorebirds, and take a virtual field trip to a solar farm. Resources in Life Science gives you a wide range of topics, including the cell cycle, genetic disorders, and bioethics.