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  • Genetic Switches

    Genetic Switches

    Click & Learn

    Learn about how gene switches can control expression of genes in different tissues.

  • From Butterflies to Humans

    From Butterflies to Humans

    Lecture

    (58 min 30 sec) How and why butterflies and fruit flies got their spots, and the fossil record for human evolution.

  • Fossils, Genes, and Embryos

    Fossils, Genes, and Embryos

    Lecture

    (58 min 30 sec) The genetic mechanisms by which evolution occurs, and an overview of the evidence for evolutionary theory.

  • Selection in Action

    Selection in Action

    Lecture

    (58 min 29 sec) Comparing the artificial selection of dogs and corn with the natural selection of the stickleback fish.

  • Evolution: Constant Change and Common Threads

    Evolution: Constant Change and Common Threads

    Lecture

    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?

  • Stickleback Environment

    Stickleback Environment

    Clip

    (1 min 27 sec) At the end of the ice age, the retreating ice sheet created many new lakes, some of which were colonized by sticklebacks.

  • Interview with Sean Carroll

    Interview with Sean Carroll

    Interview

    (4 min 56 sec) An interview with Dr. Carroll.

  • Gene Switch

    Gene Switch

    Animation

    (1 min 15 sec) Regulatory "switches" are found upstream from a gene. Regulatory molecules bind to the switches and recruit RNA polymerase to bind to the gene's promoter region, increasing the transcription of the gene into messenger RNA.

  • Paintbrush Gene

    Paintbrush Gene

    Animation

    (49 sec) In two related Drosophila species, a so-called paintbrush gene is activated to "paint" the pigment on the body. In one species, an extra switch activates the gene, resulting in spotted wings.

  • Pitx1 Expression

    Pitx1 Expression

    Animation

    (55 sec) In the stickleback fish, pelvic-fin reduction resulted from changes in the regulatory switch elements of the Pitx1 gene. In the marine ancestor, the Pitx1 gene is activated in the pelvic-fin region during development to generate the fin. In the pelvic-reduced stickleback, the regulatory switch that normally turns on the Pitx1 gene is either missing or non-functional.

  • Pocket Mouse Evolution

    Pocket Mouse Evolution

    Animation

    (1 min 5 sec) This simulation shows the spread of a favorable mutation through a population of pocket mice. Even a small selective advantage can lead to a rapid evolution of the population.

  • Pocket Mouse and Predation

    Pocket Mouse and Predation

    Animation

    (20 sec) The rock pocket mouse is found in two color variants, or morphs: light and dark. In different environments, their visibility to predators such as owls varies. The dark morph is more vulnerable on light sandy desert, and the light morph on dark lava rock.

  • Fossil Record of Stickleback Evolution

    Fossil Record of Stickleback Evolution

    Clip

    (2 min 34 sec) A quarry site in Nevada carries the evolutionary history of a population of stickleback fish that resided there when it was a freshwater lake.

  • Wing Morph

    Wing Morph

    Animation

    (29 sec) This "morph" animation demonstrates how the expression of a particular toolkit gene in a butterfly larva corresponds to the location of the wing eyespots in an adult butterfly.

  • Sexual Evolution: From X to Y

    Sexual Evolution: From X to Y

    Lecture

    (1 hr 28 sec) Dr. Page explains how successive inversions and deletions of the Y chromosome during mammalian evolution have reduced it to its present form—small and sparsely populated with genes.

  • The Meaning of Sex: Genes and Gender

    The Meaning of Sex: Genes and Gender

    Lecture

    Four talks focus on sex determination—the molecular and genetic mechanisms that determine whether an organism will be male, female or a hermaphrodite.

  • Clonal vs Sexual Reproduction

    Clonal vs Sexual Reproduction

    Clip

    (8 min 56 sec) 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.

  • The Y Chromosome

    The Y Chromosome

    Animation

    (2 min 46 sec) The Y chromosome has been likened to a hall of mirrors because its sequence contains many sections that appear to be palindromes. These palindromes provide a clue to some interesting events that may have occurred during the course of the chromosome's evolution.

  • Evolution of the Y Chromosome

    Evolution of the Y Chromosome

    Animation

    (5 min 39 sec) How did the human Y chromosome become so small relative to its X counterpart? This animation depicts the 300-million-year odyssey of the sex chromosomes that began when the proto X and Y were an identical pair.

  • Emerging Infections: How Epidemics Arise

    Emerging Infections: How Epidemics Arise

    Lecture

    (59 min) Dr. Ganem analyses the complex causes of epidemics—how changes in the environment and in human social behavior can give rise to new infectious diseases.

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