What are the major principles of evolution? What are the requirements for evolution to occur? What are the key principles behind macroevolution? What does common descent means? What happens during a speciation events? How does mass extinctions, such as meteor impacts, impact the history of life on earth? What is the origin of chloroplasts and mitochondria? How do we know that multicellularity occurred twice? What is the difference between proximate and ultimate causation in biology? What is genetic drift and when is it most likely to play a major role? What is neutral evolution? What is a gene duplication and how does it differ from exon shuffling? Why does sexual reproduction occur? Do gene trees differ from species trees as why? What is the difference between allopatric and sympatric speciation?
What does the tree of life look at? How to you build a phylogenetic tree? What is the difference between a monophyletic group and a paraphyletic group? How do we know that carnivorous plants have independently evolved over half a dozen times? Why is the evolution of endoparasites so complicated? What have the Anolis lizards been up to in the Caribbean? When did the ozone layer form and how did it impact the evolution or large, long-lived organisms? What is the Cambrian radiation and when did it occur? What is Wolbachia and how does it coevolve with its host? What are thrifty phenotypes and what is their connection to evolutionary medicine? What happens to antibiotic resistance prevalence when you ban a certain antibiotic from being used in agriculture? How can evolutionary insights improve chemotherapy strategies to extend the life of people with cancer?
Stephen C. Stearns is the Edward P. Bass Professor of Ecology and Evolutionary Biology at Yale University. His research is primarily in life history evolution and has written several books, both about introductory evolution and evolutionary medicine. He held a course in evolution, ecology and behavior at Yale in the spring of 2009 and the university put all of the video lectures on their Youtube channel later that same year. The entire playlist is available here. This lecture series consists of 36 videos spanning over 24 hours of evolutionary biology knowledge that is put in its ecological and behavioral contexts. Stearns move easily between different levels of analysis, such as basic genetics, genomic conflicts, developmental biology, the impact of environmental variation, the origin of sex, phylogeny, geology, fossils, evolutionary medicine, climate change, island biogeography, foraging strategies, game theory and altruism.
The Nature of Evolution: Selection, Inheritance, and History
This first lecture talks about the history of biological thought and the requirements for adaptive evolution by natural selection, such as traits being heritable, variation in a trait and a correlation between a trait and reproductive success.
Basic Transmission Genetics
This is another basic lecture that revolves around how genes are inherited to the next generation. What is the material basis of heredity? What are the components of the DNA double helix? What is the structure of a gene? What is the genetic code and how does DNA replication work? How does cell division occur and what is the difference between mitosis and meiosis?
Adaptive Evolution: Natural Selection
This video lecture covers the different kinds of natural selection, why the rate of evolution is sometimes rapid and sometimes slower, and about the contexts in which selection occurs.
Neutral Evolution: Genetic Drift
Evolution is more than natural selection and this lecture discuss what happens to traits that do not affect reproductive success. Do these change over time and, if so, why?
How Selection Changes the Genetic Composition of Population
There are four major genetic systems that capture most of the genetic variation and the equations behind population genetics. Which are they?
The Origin and Maintenance of Genetic Variation
What is the mutation rates in different organisms? How do overdominance, drift, selection negative frequency-dependent selection maintain genetic variation? These are many other questions are discussed in this lecture.
The Importance of Development in Evolution
Stearns highlights why developmental biology plays a crucial role in evolutionary biology. How does development constrain and facilitate evolution. How are genes regulated in development and what role is placed by concentration gradients on gene products?
The Expression of Variation: Reaction Norms
This video talks about developmental plasticity and reaction norms. Did you know that the effects of certain genes can depend crucially on the environment. How do some small crustaceans develop horns in helmets in response to dissolved molecules in the water?
The Evolution of Sex
Why and how did sexually reproduction evolve? Sex is costly and vulnerable to invasions by asexual reproducers, so why is it so common? What role does parasites and pathogen have? What about mutation and repair? The risk spreading of recombination?
Stearns explores male sterility in some plants, conflict between plasmids and bacteria, nuclear and cytoplasmic genomes, mother and father, as well as mother and fetus.
Life History Evolution
Why are some organisms big while others are small? Why do some have thousands of offspring, while some have very few? Why do some organisms become over a hundred years, while some only live a few weeks? Stearns takes us on a journey in his own research specialty that provides one of the most fascinating interfaces between ecology and evolution.
How does evolution lead to certain specific sex rations and why do these differ between organisms that have two separate sexes, organisms that are sequential or simultaneous hermaphrodites and is there ever a time where differential investment should depend on social status? Stearns takes us through the Shaw-Mohler theorem.
What is the trade-off between mating success and survival? Why do peacocks have big and beautiful tails? What is the surprising about elephant seal body length and harem size?
Species and Speciation
Stearns transitions to macroevolutionary topics and ponders different kinds of species definitions, different types of speciation, the experimental evidence for speciation, and finally the genetics of speciation.
Phylogeny and Systematics
This video lecture gives surprising results from molecular systematics, such as birds being dinosaurs, whales are closely related to horses and hippos. Stearns also explains the basics of how to build a phylogenetic tree.
Comparative Methods: Trees, Maps, and Traits
What is the connection between ancient human migration and arthropod speciation in Hawaii? Did you know the ancestors of ectoparasites on wasps where actually endoparasites? Stearns complicates the process of creating trees and maps. How do you handle the problem with species not being independent samples? How can you tell that the last common female ancestor of our mitochondrial genomes lived in a population that consisted of at least 10 000 people?
Key Events in Evolution
Stearns goes over central evolutionary events in history, such as origin of self-replicating RNAs, membrane transport, eukaryotes, and cytoskeleton.
Major Events in the Geological Theatre
This lecture takes a different perspective on the history of life and looks at events in geological time, such as origin of photosynthesis and the relationship between the ozone layer and mutation rates, algae, shelly invertebrates, invasion of land, vascular plants, mammals and humans. Glaciations and their relationship to evolution are also discussed.
The Fossil Record and Life’s History
Stearns finishes this section on the history of life by looking at the origin of the different groups of animals through examining the fossil record.
How does the intracellular parasite Wolbachia ensure that infected host becomes a female? What risks are there to the sexually reproducing host? What is the Red Queen hypothesis and how does in impact coevolution? How does coevolution work between reef-building corals and dinoflagellates? Leafcutter ants and domesticated fungus?
What is the connection between variation in response to medicine, antibiotic resistance, preeclampsia, selective abortions, imprinting and some mental illnesses, the arms race between pathogens and the host, the origin of HIV, the emergence of new infectious diseases, aging and the heterogeneous of cancer?
The Impact of Evolutionary Thought on the Social Sciences
Are humans in the middle of another evolutionary transition? What does evolution has to say about aggression and cooperation? Group norms?
The Logic of Science
Stearns jumps into the philosophy of science. What is science? Why is it valuable to keep multiple, alternative hypotheses in mind when doing science? What is falsifiability and paradigm shifts? Why are these simplistic views problematic? Why is the postmodernist attack against science largely invalid?
Climate and the Distribution of Life on Earth
This lecture starts the ecology block of the course, looking at the background theater in which evolution occurs. What is the physics and chemistry of climate? How do hurricanes and El Niño Southern Oscillation work? What is the history of climate on earth? What is a biome?
Interactions with the Physical Environment
How do animals and plants reduce water loss? What about regulating body temperature? What is a concurrent heat exchanger? This lecture deals primarily with physiological ecology.
Population Growth: Density Effects
This video lecture deepens our understanding of population growth and the effects of density and age.
Organisms do not just compete with other individuals within the same species, but also with other species. Stearns focus on experimental evidence of interspecies competition, such as birds, barnacles, Paramecium and flowering plants.
What happens when you remove an apex predator? How does size-selective predation affect freshwater communities? What is a trophic cascades? How can you reconstruct the history of forests from pollen? What is a meta-community?
Island Biogeography and Invasive Species
Island biogeography involves an equilibrium between rates of colonization and extinction, a source population, and effects related to areas and distances. But there are criticisms of these ideas. What are they?
Energy and Matter in Ecosystems
This lecture transitions from biological interactions between organisms and physiology to the flow of matter and energy through ecosystems, biomes and the planet. What is the difference between tropical forests and limestone from coral reefs? How does the phosphate cycle work?
Why So Many Species? The Factors Affecting Biodiversity
Why should we care about biodiversity? Is there an ongoing extinction crisis? What are the ecological, economic, evolutionary perspectives on biodiversity?
Economic Decisions for the Foraging Individual
What does the marginal value theorem have to do with animal foraging? How do we know that a male dung fly should have sex for about an hour? How do Marsh tits deal with variation in seed availability? What is aggressive mimicry?
Evolutionary Game Theory: Fighting and Contests
How can we apply mathematics to evolution of behavior? What is the Dove-Hawk game? How does prisoner’s dilemma work? Are there any good biological examples of these games, or do real-world scenarios differ in fascinating ways?
Mating Systems and Parental Care
What mating systems do elephants have? What is polygyny and polyandry and when are they likely to occur? Why should high-status females invest in males? Why do siblicide occur in raptors? What are the benefits and costs of parental care?
Alternative Breeding Strategies
Why are alternative breeding strategies crucially dependent on frequency? What are the conditions for female choice? What is sperm competition and how does it work? How do small male bullfrogs try to sneak onto females? What are parasitic male reproductive behavior? Why are alternative breeding strategies so common in fish? This penultimate lecture covers this controversial topic.
Selfishness and Altruism
Competition can easily be understood in evolutionary terms. But what about altruism? This final lecture discuss kin selection, reciprocal altruism and ecological constrains and punishments. Why doesn’t group selection work?
This course provides a fascinating and straightforward introduction to modern biology with a strong focus on evolutionary biology, both molecular mechanisms, deep geological time and animal behavior. The course website also has made two midterm exams and their solutions available. Should these links every go dead, the Internet Archive also has both of them cached here and here.