Peppers_Biology

Scientists have discovered a previously unrecognized genus of extinct horses that roamed North America during the last ice age. The new findings are based on an analysis of ancient DNA from fossils of the enigmatic 'New World stilt-legged horse'

Archived 1/19/17 EPA website

How can a mixture of molecules, too small to be seen with even a high-powered microscope, be separated from one another? Such was the dilemma facing scientists until the development of a process that is now standard in laboratories worldwide-gel electrophoresis. Laboratories rely heavily on this proven and reliable technique for separating a wide variety of samples, from DNA used in forensics and for mapping genes, to proteins useful in determining evolutionary relationships.

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.

It is now well known that non-native species have the potential to be harmful to an ecosystem, but that wasn't always the case, and getting rid of non-native invasive species is usually a difficult task. This brief, interrupted case study tells the story of kudzu's introduction into the United States in the late 1800s. It also examines (and even questions) how we define words like "native" versus "non-native" and "invasive" versus "non-invasive." Students will learn how invasive species impact ecosystems and why some non-native species never become established. They also will address questions related to eradicating non-native invasive species. For example, is it okay to attempt to get rid of a non-native species with another non-native species? As part of the activity, students also will have to decide whether or not kudzu should be considered "native" since it has been in the United States since 1876. Originally designed for a general biology course for majors, the case has also been used in a biology class for non-majors as well as an environmental biology class.

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.

This case study uses an interactive activity to illustrate density dependence in ecology classes. We developed a "hunt" using paper butterflies with warning signals on the upper side of the wings and symbols that indicate if a butterfly is noxious underneath the wings. Butterflies are distributed in four different patches with varying densities of noxious and palatable butterflies, simulating Batesian or Müllerian mimicry. Students can catch as many butterflies they want for a period of time, but if they catch more than three noxious butterflies they are out of the game. After the activity, students calculate the survival rate of each type of butterfly in each patch and discuss the implications of density and warning signals according to their results. Students then answer questions and build graphs using the data from the activity and knowledge from the class and the discussion. With this case study, students will be able to understand negative and positive density dependence, as well as predation, learning, and convergent evolution, while recalling or being introduced to Batesian and Müllerian mimicry.

The scientists are from the Centers for Disease Control and Prevention, and they have embarked on this watery journey to solve a decades-old mystery about a rare and fatal disease: monkeypox. A cousin to the deadly smallpox virus, the monkeypox virus initially infects people through contact with wild animals and can then spread from person to person. The disease produces fever and a rash that often turns into painful lesions that can feel like cigarette burns. It kills up to 1 in 10 of its victims, similar to pneumonic plague, and is particularly dangerous in children. Monkeypox is on the U.S. government list of pathogens such as anthrax and Ebola with the greatest potential to threaten human health. There is no cure.

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.

Paul Andersen explains how eukaryotic cells were formed through a process of endosymbiosis. He describes how aerobic bacteria became mitochondria and cyanobacteria became chloroplasts. He mentions an example of symbiosis that occurs today and mentions the importance of Dr. Lynn Margulis in the development of this modern theory.

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.

Dr Adam Rutherford discusses the early evolution of complex life on Earth with geneticists Professor Steve Jones and Dr. Nick Lane.

Scientists have discovered that the newly found Tapanuli orangutan of Sumatra is more closely related to its cousins in Borneo than it is to its fellow Sumatran apes. The Tapanuli population numbers only around 800 individuals.

Redwood trees, those ancient living monuments to California's past, are as mysterious to science as they are magnificent, so a team of researchers led by a San Francisco conservation group is attempting to unlock the genetic secrets of the towering conifers. Scientists affiliated with the nonprofit Save the Redwoods League are attempting for the first time to sequence the genomes of coast redwood trees and their higher-elevation cousins, the giant sequoias, a complex and expensive undertaking that experts hope will help preserve the trees' ancient groves as the climate changes over the next century.

This flipped case study tells the story of Joyce, a biology student who notices the development of some unusual symptoms (foot slapping and slurred speech) in her mother. In an effort to understand the cause, Joyce views a documentary-style trigger video (created by the case author) that suggests to Joyce that her mom may in fact have amyotrophic lateral sclerosis or ALS. The rest of the case walks Joyce through understanding how normal neurons compare to neurons in ALS patients and how that might affect muscle function. The case explores the link between genes, particularly SOD-1, to the formation of malformed proteins and its potential role in the development of ALS. The case concludes with a discussion of drug development and highlights the timeline and costs associated with drug discovery as Joyce becomes concerned about the lack of drugs in the pipeline for ALS, which her mother is ultimately diagnosed with. The case is appropriate for a number of classes including general biology, biotechnology, anatomy and physiology, upper level-cell biology, or any human health and disease-related course.

A simple animation explaining what Turner Syndrome is, how it is caused, the symptoms, and how it is diagnosed and treated. We hope this video will be useful to you and those around you.

"Some of the most exciting things that we've seen from looking at gene expression in space is that we really see an explosion, like fireworks taking off, as soon as the human body gets into space," Twins Study principal investigator Chris Mason said in a statement.

Behind every fart (and poop) is an army of gut bacteria undergoing some crazy (and crazy useful) biochemistry. Learn what they have in common with beer brewing, and why we'd want to know about this science anyway...

By taking near-atomic, high-resolution X-ray images of proteins from primitive bacteria, investigators at Arizona State University and Pennsylvania State University have extrapolated what the earliest version of photosynthesis might have looked like nearly 3.5 billion years ago.

In this clicker case study for a flipped classroom, students familiar with the stages of meiosis work in small groups to determine the predicted genetic makeup of the parthenogenetic offspring of a Komodo dragon, based on four different types of parthenogenesis. Students then learn about the actual genetic makeup of the offspring and determine how meiosis was modified to allow parthenogenesis in this fascinating lizard. The sex of the offspring is explained, based on ZW/ZZ sex determination. A video specifically made for this case prepares students for the in-class activities, which are guided by a PowerPoint presentation. The case also examines how facultative parthogenesis may be adaptive in Komodo dragons and the implications of facultative parthogenesis to conservation of these vulnerable lizards. The case was developed for a general biology class, but could also be used in an introductory course on conservation or cell biology.