Lecture 4: From Butterflies to Humans
by Sean B. Carroll, Ph.D.
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Introduction by HHMI Program Officer Dr. Dennis Liu
Introductory interview with Dr. Sean Carroll
Darwin's theory helped in understanding new discoveries
Henry Walter Bates and his trip to the Amazon
Bates returned with 8,000 new species
Batesian mimicry in butterfly markings
Bates's book,
The Naturalist on the River Amazons
Data from butterflies offers insight into our own evolution
How did fruit flies and butterflies get their spots?
Video: Fruit fly courtship behavior
Sexual selection and courtship behavior
Video: Courtship dance of a different species
Spots evolved via new use of old toolkit gene
Butterfly wing spots: An adaptation for survival
Reuse of a toolkit gene creates the wing spots
Animation: Toolkit gene expression at center of wing spots
Much of diversity is due to new uses of existing genes
Genes are reused in different ways via genetic switches
Animation: Paintbrush gene switch in the fruit fly
Evolution acts by gain and loss due to chance mutations
Q&A: Are the switch regions turned off or deleted?
Q&A: Spots the only difference between fruit fly species?
T.H. Huxley in 1863 on human evolution
First Neanderthal fossil supported Huxley's ideas
3-million-year-old bipedal hominid: Lucy
Older evidence of bipedal hominids: Laetoli footprints
Fossil record of Homo sapiens
The evolutionary tree of hominids
Problems with finding hominid fossils
Homo sapiens are a very new species
Hominid skull evolution
Evolution of larger brain size in hominids
Traits that distinguish humans from other apes
What can we learn about human evolution?
Comparing the chimp and human genomes
Loss of jaw-muscle gene could allow a larger skull
Modern genetics tries to pinpoint key evolutionary changes
Resistance to the theory of evolution
Darwin's "endless forms" are endangered
The alternative to thinking in evolutionary terms
Q&A: Why did some hominids last longer than others?
Q&A: Could some hominid species just be variants?
Q&A: Gene or control region mutations more likely?
Closing remarks by HHMI President Dr. Thomas Cech