Lecture 3: Fossils, Genes, and Embryos
by David M. Kingsley, Ph.D.
Play Lecture Three in Full
Introduction by HHMI President Dr. Thomas Cech
Introductory interview with Dr. David Kingsley
Laws of nature lead to natural selection
Descent with modification explained conundrums
Major questions resulting from Darwin's theories
Is the earth too young for descent from a single ancestor?
Modern physics shows that the earth is 4.6 billion years old
Where are the transitional forms in the fossil record?
Billion-year-old fossils of early lifeforms
The reinvasion of water by land mammals
Traits suggest manatees evolved from land mammals
Transitional manatee ancestors
The dolphin and its transitional forms
Fossils of transitional forms in stickleback fish
Video: Fossils show 25,000 years of stickleback evolution
Transitional fossils are everywhere
Q&A: What caused rapid replacement in the fossil record?
Q&A: What were the first common ancestors?
Q&A: Does evolution address how life started?
Q&A: Can the evolution rate change over time?
Can rare forms be swamped out?
Mendelian genetics: Variants are not lost by blending
Pocket mouse simulation and real stickleback data
Are animals too different to share an ancestor?
Organisms share molecular pathways and enzymes
Organisms share DNA as the basis for heredity
Different animals share developmental pathways
Hox
"toolkit" genes guide development in mice and flies
Eye development in humans, flies, and mice uses
Pax6
gene
Overexpressing
Pax6
in flies creates eyes in wrong places
Pax6
is a toolkit gene that turns other genes on or off
Animation: How regulatory switches work
Forelimb vs. hindlimb development in vertebrates
Master regulators are expressed in one limb or other
Pitx1
is the master regulator for stickleback hindfin reduction
Pitx1
plays multiple roles in development
Variants have changes in switch regions, not in
Pitx1
Animation:
Pitx1
switching in two types of sticklebacks
Genetic basis of evolutionary change in species
Darwin's predictions supported by multiple sciences
Q&A: How do major changes in gene structure occur?
Q&A: Are the extra eyes on the
Pax6
flies functional?
Q&A: Why are some religions and evolution in conflict?
Q&A: How do you look for single-celled fossils?
Q&A: Has the evolution of viruses been traced?
Closing remarks from HHMI President Dr. Thomas Cech