This Click and Learn explains how DNA sequences can be used to generate such trees, and how to interpret them.
West Nile virus infects mosquitoes, birds, and people—with very different consequences.
Comparing features of a 4.4-million-year-old fossil skeleton to those of human and chimpanzee skeletons sheds light on our evolutionary history.
Lactose tolerance, sickle cell anemia, and bitter taste perception are three examples of recently evolved human traits.
Lactase persistence results from a mutation that changes how transcription factors interact, thereby affecting gene expression.
This survey, developed by Horne and Ostberg, will let you determine if you are a morning or an evening person.
Answer the questions in this online quiz to test your knowledge of what determines the sex of a human, a fruit fly, and a snapping turtle.
Paleoanthropology provides an excellent example of the scientific process at work.
Learn about the nature of vector-borne diseases, and the life cycle of the dengue vector mosquito.
Learn the principles of how DNA is sequenced and assembled into whole genomes using the Sanger method, shotgun sequencing, or ultra-deep sequencing.
Answer interactive questions to explore the logic of the Virochip microarray design, particularly how evolutionary relationships can be used to detect new viruses.
Explore principles of taxonomy by sorting seashells according to their morphological characteristics and constructing an evolutionary tree.
Explore the biology of the symbiotic relationship between the Hawaiian Bobtail squid and bioluminescent bacteria Vibrio fischeri.
Understand how quorum sensing works by reasoning through experiments involving genetically-engineered bioluminescent bacteria.
Learn why verifying a person's gender may be harder than you think.
How both gene chips and microarray slides are created.
Small molecules are chemicals that can interact with proteins to affect their functions. Learn about the structure and biological functions of various small molecules like sugar and caffeine.
Different gaits employed by animals and how the nervous system is able to switch between them.
Measuring neuronal activity, generating action potentials, and recording the firing of individual neurons.
A brief discussion of what makes a virus a retrovirus, and how they differ from other types of viruses.
Problems associated with adherence to antiviral drugs, and a student activity that mimics adherence to a multi-drug regimen.
An overview and comparison of different regenerative capabilities in many different organisms.
An exploration of current and future therapies.
Learn about artificial and natural selection.
Learn about how gene switches can control expression of genes in different tissues.
RNA interference is an exciting new research tool for shutting down genes. It could also yield new medical treatments.
This mini-lesson covers the research on telomeres that has happened since the 1995 Holiday Lectures.
There is no way to directly measure how much fat a living person has. Learn about the various methods used by researchers and fitness advisors to estimate a person’s body fat.
This slide show delves into the various molecular shapes that fat can take.
This slide show explores some of the ways the body processes fat, including digestion, transport, conversion, and energy extraction.
Learn about what p53 does, and how interfering with its function can lead to cancer.
DNA microarrays, or gene chips, are an important new technology for genomic research. Learn how researchers use computing to analyze and interpret the huge datasets generated by microarray experiments.
All living humans originated from populations of ancestors who migrated out of Africa less than 100,000 years ago. Learn how scientists have used genetic markers to trace the migration routes and origins of modern human populations.
The record of life on Earth stretches over 3 billion years. Deep time and Earth history are keys to understanding the present.
Earth's climate is a complex system controlled by many factors. This Click and Learn will examine the two most important factors: solar radiation and the composition of Earth's atmosphere.
Explore the changes in oxygen levels throughout Earth’s history and discover their impact on life.
Finches discriminate between members of their own species and those of a closely related species based on song and appearance.
This interactive explores different anatomical features of the human body and what they reveal about the evolutionary history we share with other organisms, including earlier, long-extinct species.
The fossils of transitional creatures were key evidence for Darwin’s evolutionary theory, but none had been found when he published On the Origin of Species. Now, there are many examples of such fossils, which clearly show that big evolutionary leaps consist of many smaller steps.
A highly visual interactive timeline for exploring the history of Gorongosa National Park, from its beginnings as a hunting reserve and decline in the wake of a civil war, to its return to being one of the world’s foremost wildlife treasures and case studies in conservation biology.
This Click and Learn describes how understanding the structure of the BCR-ABL kinase led to the development of an effective treatment for chronic myeloid leukemia.
Compare and contrast the anatomy of the heart and the circulatory systems of major vertebrate groups and gain insights into their evolution.
This interactive map of Gorongosa National Park allows users to explore different features of the park, including key components of the conservation strategy.
Explore the phases, checkpoints, and protein regulators of the cell cycle in this highly interactive Click and Learn and find out how mutated versions of these proteins can lead to the development of cancer.
Learn about the different ways scientists are able to detect when genes are being expressed in various tissues.
RNA is an information molecule that can also function as an enzyme. Learn about the many different forms that RNA can take.
Learn about the structure and function of this fascinating cellular machine.
Take this quiz to see how well you understand some of the topics covered in the 1999 Holiday Lectures on infectious disease.
Explore key human impacts on the environments and how they have affected Earth’s landscape, ocean, atmosphere, and biodiversity with this engaging interactive.
An overview of the immune system, concentrating on the roles played by B and T lymphocytes, and the antigen-presentation system.