One of the failed hypothetical models of DNA is Linus Pauling's triple helix model. This structure would be unstable under normal cellular conditions.
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...
Dr. Michael Gottlieb was the first physician to notice the new disease of AIDS.
Dr. Kandel illustrates the practice of the now-debunked theory of phrenology.
Where and when did humans arise? What distinguishes us from other species? Did our distant ancestors look and behave like us?
How has the amazing diversity of plants and animals evolved? What can fossils, butterflies, and stickleback fish tell us about the deep common ancestry of all living forms?
How Darwin came to publish The Origin of Species, and examples of how quickly evolution can change a population.
The genesis of AIDS, identifying HIV as the virus that causes AIDS, and the modern global epidemic.
Dr. Donald Ganem describes how epidemiologists, physicians, and microbiologists work together to identify and study pathogens.
What is mind? Can molecular biology help us understand mental function?
The history of localization of function in the brain, and research that led to the understanding of localization of memory.
The following classroom-ready resources complement The Day the Mesozoic Died, which tells the story of the extraordinary detective work that led to the stunning discovery that an asteroid struck Earth 66 million years ago, triggering a mass extinction of animals, plants and even...
A short article by Dr. Sean B. Carroll detailing the discoveries covered in the film The Day The Mesozoic Died.
The following classroom-ready resources complement The Making of the Fittest: Natural Selection in Humans, which describes the connection between malaria and sickle cell anemia—one of the best-understood examples of natural selection in humans.
A worksheet designed to show students how scientists make their discoveries. It provides students with background information about how Dr. Allison's work built upon the contributions made by other scientists.
A worksheet designed to actively engage students as they watch the film. Students are asked to answer questions pertaining to the information provided in the film.
Has Earth changed over deep time? How did Earth shape life and life shape Earth? What does Earth's climate in the distant past tell us about the future?
The theory of plate tectonics took many decades to become accepted. The process by which it was finally accepted provides a fascinating glimpse into how scientists build new scientific consensus.
Scientific evidence for global climate change is overwhelming, yet the American public remains skeptical. History provides insights into how a Cold War-era think tank became an influential source of anti-regulation sentiment.
Students discuss the short film after a screening at the 2012 Holiday Lectures on Science.
Continents rose in elevation after ice sheets from the last ice age retreated. This suggested that the underlying mantle is pliable.
The concept that continents float on a pliable mantle is an important element of the theory of continental drift.
Dr. Oreskes explains her switch from research science to science history, and what led her to write Merchants of Doubt...
An early model of continental drift proposed that parts of continental plates can sink into the mantle, allowing for movement.
An early continental drift model proposed that mantle convection can produce continental movement and new plate formation.
This hands-on activity requires students to “visit” different K-T boundary sites.
Plate tectonics is the unifying theory of Earth science.
The golden birdwing provided a striking clue to the natural origin of species.
This activity supports the viewing of the film The Origin of Species: The Making of a Theory. Before and after watching the film, students discuss and evaluate several statements about Charles Darwin, Alfred Russel Wallace, and the specific evidence that led each of them to the theory...
This activity supports the HHMI short film The Origin of Species: The Making of a Theory. Students are presented with a map of the Malay Archipelago and some field notebooks with observations of animals. By plotting which animals are found on which island, the students discover the...
Students are challenged to identify “fact patterns,” or patterns that emerge from a collection of different facts and observations, and draw conclusions about what they suggest.
The richness and diversity of life raises two of the most profound questions in biology: How do new species form? And, why are there so many species?
The following classroom-ready resources complement The Making of the Fittest: The Birth and Death of Genes, which describes how scientists have pieced together the evolutionary history of the Antarctic icefish. The icefish makes an excellent case study for genetic evolution as...
The disappearance of the dinosaurs at the end of the Cretaceous period posed one of the greatest, long-standing scientific mysteries. This three-act film tells the story of the extraordinary detective work that solved it.
The epic voyages of Darwin and Wallace led each to independently discover the natural origin of species and to formulate the theory of evolution by natural selection.
The Double Helix is the story of the scientists and evidence involved in one of the most important scientific quests of the 20th century: the discovery of the structure of DNA.
The following classroom-ready resources complement The Double Helix. This short film describes the evidence that led James Watson and Francis Crick to the discovery of the double-helical structure of DNA and how the structure immediately revealed how genetic information is stored and...
This activity can be used in conjunction with the short film The Double Helix. It introduces students to the classic experiment by Matthew Meselson and Franklin Stahl, which revealed that DNA replication follows the semiconservative model.
Scientists have pieced together the evolutionary history of the Antarctic icefish. The icefish makes an excellent case study for genetic evolution as both the gain and loss of genes have led to key adaptations.
Dutch draper Antonie van Leeuwenhoek (1632–1723) built microscopes that allowed him to observe never-before-seen microorganisms, including this rotifer. He called them “animalcules.”
This animated short video illustrates the life of Alfred Russel Wallace, who independently formulated the theory of evolution by natural selection at the same time as Charles Darwin.
This animated feature celebrates 17th-century citizen-scientist Antonie van Leeuwenhoek, whose discoveries of microbes changed our view of the biological world.