A quarry site in Nevada carries the evolutionary history of a population of stickleback fish that resided there when it was a freshwater lake.
During the process of trying to elucidate the structure of DNA, Jim Watson made some cardboard models to try to understand how DNA nucleotides are paired. It helped him visualize how hydrogen atoms of paired nucleotides interact with each other to form a symmetrical structure that fits the...
The small molecule 'furrowstatin' exemplifies the power of using small molecules to investigate life's processes. When applied to dividing cells, the furrowstatin halts cell division.
Adam Barrett describes his seven-drug antiretroviral regimen and the importance of adherence.
Aplysia californica is a marine snail with a simple nervous system suitable for research on learning and memory.
A touch to the Aplysia's siphon causes a gill withdrawal, a simple reflex for studying memory.
A live recording of muscle activity from Dr. Jessell's biceps and triceps muscles.
Dr. Brett Finlay shows how bacteria can grow rapidly to incredible numbers, and also explains what limits this explosive growth.
A demonstration by Dr. Meyer showing how a balance of molecular elements trigger genetic pathways that determine the sex of a C. elegans worm.
Air is an invisible gas as are hydrogen and helium. How can you tell if a balloon contains hydrogen? Hydrogen has particular physical and chemical properties that can be tested. Dr. Cech enlists student volunteers to show how a chemical reaction can be used to identify a substance.
Adam Barrett, a nurse who is HIV positive, discusses his first symptoms and the challenges of adhering to a drug regimen.
The fight against dengue fever, and the mosquitoes that carry the virus, is being carried out by "brigadistas" in Managua's neighborhoods. Spanish with English subtitles.
Charles Runckel, a graduate student in the DeRisi lab, uses the Virochip to examine the mystery of bee colony collapse disorder.
Zinhle Thabethe describes how antiretroviral therapy has changed her life.
Are you a night owl or a morning lark? Noted researcher Dr. Seymour Benzer discusses how the difference between he and his wife sparked his interest in the topic of biological clocks.
The bobtail squid swims during the night to hunt. During the day, it burrows to hide from predators.
A demonstration by Dr. Barbara Meyer of how a branched genetic pathway can be affected by mutations in different parts of the pathway.
Corn was originally bred from the teosinte plant by native Mexican farmers. The morphologies of modern-day corn and teosinte plants are compared to illustrate how artificial selection can bring about dramatic changes in plants.
Even when distracted by food, the cat's brain encodes and retains the location of an obstacle.
Without an appropriate catalyst some chemical reactions would be so slow as to appear not to occur at all on the human timescale. However, when catalyzed, these reactions can be very dramatic.
HHMI President Dr. Thomas Cech discusses the path he took to become a scientist and his reaction to receiving the Nobel Prize.
Time-lapse microscopy showing cell division from 1 to 2 to 4 cell stages in C. elegans with fluorescent chromosomes.
Video of the fertilization of the C. elegans oocyte, the fusion of the egg and sperm nuclei, and the egg laying.
Video microscopy of mating between a male and a hermaphrodite C. elegans roundworm.
Video closeup of the C. elegans sperm that moves like an amoeba.
“The Assemblers” (Peter Skewes-Cox and Dr. Graham Ruby) sing about DNA and proteins.
Dr. Brett Finlay enlists a student volunteer to show the surprisingly high amount of bacteria found in his own mouth.
What does a stack of fruits and vegetables have to do with the theoretical advantages of sexual reproduction? Find out in this demonstration with student audience members and Dr. David Page.
Dr. Vogelstein shows video taken during a colonoscopy and the removal of a polyp.
Dr. Jessell's leg muscle activation patterns are recorded during walking.
A patient can both comprehend and articulate language, but cannot verbalize what is a clear idea in her mind.
Dr. Olivera demonstrates a live specimen of Conus striatus.
A growth cone contacts a repellant molecule on another axon, collapses, and withdraws.
This species of cone snail immobilizes its prey in a split second with lightning-strike cabal toxins.
A fish-hunting cone snail strikes its prey with a venomous harpoon, causes paralysis, and eats it.
Larger cone snails produce more venom and are more dangerous to human beings in an accidental stinging.
A worm-hunting cone snail species feeds on fireworms, and is unaffected by the prey's sharp bristles.
A species of fish-hunting cone snail quickly immobilizes its prey and swallows it.
A snail-hunting species of cone snail stings its prey repeatedly, inducing the prey to thrash about.
Unlike a hook-and-line type fish-hunter, a net-hunting cone snail lures its prey into its wide mouth.
Video microscopy of a cytotoxic T lymphocyte in action.
Dr. Rosenthal describes how antlers are one of the few examples of complete mammalian regeneration.
Using tic tac mints as anti-HIV drug stand-ins, students experience the challenges of adhering to an antiretroviral regimen.
A live demonstration of how a rapid antibody-based HIV test works.
Several members of a Nicaraguan research team describe the impact of technology transfer.
The many forms of dogs that exist today were all created through selective breeding from the dog's ancestor, the wolf. In a span of less than 10,000 years, breeders have changed traits and body shapes of dogs by artificial selection-for example, emphasizing different aspects of hunting and...
Diversity-oriented synthesis (DOS) is a strategy used by chemical biologists to create a huge diversity of small molecules with potentially useful properties. A scientist working in Dr. Stuart Schreiber's lab shows us how engineering, computer science, chemisty, and biology are all used in DOS...
Fossilized dung beetle balls are part of a comprehensive fossil collection project to reconstruct the habitat of Ardipithecus ramidus.
Dr. Christine Seidman describes a live demonstration of an echocardiogram, with a description of the parts of the heart that are visualized.
Stone tools similar to those found at prehistoric archaeological sites can be made by fracturing rocks, a technique known as flintknapping.