Lecture 1: Darwin

How does evolution work?

is the change in allele frequencies in population over generations due to natural selection, genetic drift, gene flow, and mutation

Who was Charles Darwin?

• Proposed the theory of evolution through natural selection

• Helped to revolutionize our understanding of diversity of life on earth

What was the Modern Synthesis?

• combined Darwin’s theory of natural selection with Mendelian genetics

• Key Ideas:

  • evolution is a change in allele frequencies

  • population evolve, not individuals

  • genetic variation is heritable and arises from mutations and recombination

  • natural selection acts on existing variation to produce adaptation

  • genetic drift, gene flow, non-random mating

  • inheritance is non-blending

  • speciation occurs through gradual accumulation of genetic differences

  • evolution is gradual

  • mico and macro evolution are connected

What is primatology?

the scientific study of primates, including their behavior, biology, ecology, and evolution, to understand both nonhuman primates and humans

Define human behavioral ecology

studies how human behavior varies in response to ecological and social environments and how that variation affects survival and reproductive success

What is evolutionary medicine?

explains diseases as the result of evolutionary trade-offs, natural selection, and mismatched between our evolved biology and modern environments

ex: antibodies don’t create resistance, natural selection favors resistance microbes

cancer requires cell mutations, some mutations allows cells to divide faster, avoid death, and evade immune system

microbes evolve quickly in repose to antibiotics, vaccines, and immune systems (host-pathogen coevolution)

mismatch: our bodes evolved under hunter-gather conditions bit modern environment is very different

craving sugar, stress response, immune system

natural selection didn’t design us for modern life !

What was the malthusian catastrophe? How is it related to competition?

highlights how limited resources create competition, which leads to differential survival and reproduction

the core mechanism of natural selection

What were Darwins Postulates?

1. there must be a struggle for existence (more organs than can survive + limited resources)

2. there is variation in features related to survival and reproduction

3. his variation is passes on from generation to generation

How does evolution work?

fitness - potential for an individual to survive

reproductive success - # of reproducing offspring an individual produces

natural selection - differential survival and reproduction due to differences in phenotype

Name some examples of adaptation by natural selection

ground finches

Darwin’s Finches

After the drought, population of the finches reduced

This caused beak lengths to vary bc it effected survival

Beak depth passed on from parent to offspring