Lecture 1

• Biological evolution


  A change in allele frequencies in a population over generations
• Evolution is a population phenomenon, not an individual phenomenon
• Factors that change allele frequencies

  • Mutation
  • Drift
  • Migration
  • Selection
• Adaptations


  • They have evolved (gradually) via natural selection
  • They confer different levels of fitness, leading to greater survival and reproductive success in some organisms over others
• All organisms share a common ancestor
• Species


  They form when populations become reproductively isolated from one another
• This explains the vast diversity of life observed today
• Evolution due to mutation, drift, migration and selection

  1. Variation

  2. Heritable genetic variation

  3. Competition and differential fitness
• Typological thinking (or essentialism)

  • Species are composed of similar individuals sharing a fixed set of characteristics
  • Each individual is an imperfect manifestation of the species' perfect, unchanging "essence"
• Population thinking


  • A species does not have an unchanging "essence"; a species is just a collection of varying individuals
  • Variation among individuals in the species at a given time is part of what defines the species at that time
  • Variation is the fuel for natural selection
• Evolution is an observable process by which populations change over time
• Scientific theory


  • A well-evidenced explanatory framework
  • Unlike a colloquial "theory", a scientific theory never becomes a scientific law
• Evolutionary theory explains the fact of evolution
• Evolutionary theory is an active field of research, so some aspects of current evolutionary theory are likely incomplete or incorrect
• Evolutionary Biology


  • It is partially a historical science
  • Evolutionary history and evolutionary causes usually must be inferred from the evidence
• One hallmark of a good scientific theory is its ability to make successful predictions
• Predicting Tiktaalik


  1. Palaeontologist Neil Shubin hypothesized a creature with both fish and tetrapod traits

  2. Shubin predicted that rocks ~375 million years old were likely to contain fossils of transitional creatures

  3. In 2004, Shubin and his team discovered the fossil of Tiktaalik roseae on Ellesmere Island, which had characteristics of both fish and tetrapods
• Theodosius Dobzhansky: '"Nothing in Biology makes sense except in the light of evolution"'
• Proximate cause


  How? - Mechanistic explanation
• Ultimate cause


  Why? - Evolutionary explanation
• Female birds do not sing because they do not need to attract their mate
• Fields impacted by evolutionary theory

  • Medicine
  • Agriculture
  • Forensics
  • Computer Science
• Evolution of antibiotic resistance

  • Livestock improvement
  • Use of phylogenetics to solve crimes
  • Evolutionary algorithms to solve complex problems

  
• In 1990, the US CDC received reports of an HIV-positive woman whose only possible source of HIV infection was her dentist
• A phylogenetic tree was constructed using DNA sequences of the HIV-1 env gene, which showed that DNA sequences of five patients are nested within samples taken from the dentist
• This was the first documented case of clinical HIV transmission, though the exact method of transmission is unknown
• Evolutionary algorithms


  They find good solutions to complex problems through digital "natural selection"
• Religious affiliation plays a role in how Canadians feel about discussing creationism in the classroom

  
• Naturalistic fallacy


  Attempting to derive a moral principle from a natural fact
• Evolutionary theory is descriptive, not normative
• Evolutionary theory cannot be used to justify moral claims or to prove/disprove theological claims
• Evolutionary theory may be incompatible with literal interpretations of some passages in some religious texts, but many religious people accept evolution
• Some UNB profs who study evolution

  • Jason Addison
  • Adrian Reyes-Prieto
  • Aurora Nedelcu
  • Dion Durnford
  • Amy Parachnowitsch
  • Alla Gagarinova

  
• Other evolution courses at UNB

  • BIOL 3113 - Evolutionary Ecology
  • BIOL 3241 - Molecular Evolution
  • BIOL 3293 - Population Genetics
  • BIOL 3873 - Ethology
  • BIOL 4123 - Evolutionary Medicine
  • BIOL 4523 - Phylogenetics
  • BIOL 4533 - Bioinformatics
  • BIOL 4581 - Molecular Techniques in Eukaryotic Microbiology
• Recommended evolutionary biology textbooks

  • Evolutionary Biology by Douglas J. Futuyma and Mark Kirkpatrick
  • Evolution by Douglas J. Futuyma and Mark Kirkpatrick
  • Evolutionary Analysis by Scott Freeman and Jon C. Herron
• Evolutionary biology trade books

  • The Beak of the Finch by Jonathan Weiner
  • The Blind Watchmaker by Richard Dawkins
  • Your Inner Fish by Neil Shubin
  • The Selfish Gene by Richard Dawkins