Ch2 Development of Evolutionary Theory Flashcards
Stasis vs. Change
Stasis
- Things not changing, (geographic landscapes and organisms) everything exists like it always had
Change
- Idea of change is relatively new in Western science (17th century)
- Not used to gradual change, all changes had been earthquakes etc.. No one had seen the evolution of a new species
Fixity of Species
- The notion that species were created once and did not change after that
- “God’s great design”- Driven by Christianity
Plato
- Forms could only be perceived by the mind
- “reality existed as the form of the thing we interpret as in-perfect”
- It was our imperfection that prevented us from seeing things in their true form
Aristotle
- Great Chain of Being
- Ordered, hierarchical, static view
- Essentialism- all things exist in a fixed position as they are where they are
- Simple to complex
European Middle Ages (5th -15th AD)
- Ideas of Christianity were the only “truth”
- To challenge this idea was punishable by death
- All life on earth was created by god exactly as it exists today
- Fixity of Species
- Why anatomical structures look and work the way they do
God the “grand designer” made everything in a perfect form to meet the purpose they were required
European Enlightenment (17th-19th C)
- Socio-political, economic, and scientific revolution
- Set off by debate about whether earth revolves around the sun
Geocentrism
- The idea that we are the centre of the universe
- The sun revolves around the earth
Heliocentrism
- Argued earth goes around the sun
- Challenged the perception that we are the centre of the universe, and suggested that we are just one of many planets
Three Major Paradigm Shifts
- Time
- Diversity
- Mutability
Time: James Usher
Based his chronology on:
- Lifespan of makes from the old testament
- Length of Reign of kings
- Theorized the age of the earth and the age of mankind 4004
Time: James Hutton
- Uniformitarianism
- Erosion, replacement, etc. of rocks, and realized that these changes must have taken an infinite amount of time to get to where it is now
- Came up with the idea that the same forces that were operating in the past and present are the same, sediments build up, volcanoes emerge
Time: Georges Cuvier
Catastrophism
- He proposed that there were “addition” events that happened after catastrophic events, creating more animals (god)
- Father of vertebrate palaeontology
- Developed comparative method that established extinction as a fact
- Compared fossils to living forms of those animals
- **Did not believe in evolution
Diversity: John Ray
- Came up with species and genus
- Placed reproductively isolated organisms into categories
- Groups of plants and animal separated from other groups by ability to mate and produce fertile offspring
Diversity: Carlous Linnaeus
- Founded modern method of taxonomic classification Ex. CLASS Mammalia ORDER Primates GENUS Homo SPECIES Sapiens
- Included humans in the scheme – controversial
Mutability: Count Buffon
- Founder of zoogeography
- Strong links between biology and geography
Micro vs. Macroevolution
Micro
- Change in frequency of characteristics within a population over the span of a few generations
Macro
- Speciation events, generally occurring over a long period of geologic time
Jean-Baptiste Lamarck
1809 book “Zoological Philosophy: Exposition with Regard to the Natural History of Animals”
Two laws:
- Use and disuse
- Use or disuse will cause development or reduction of parts - Inheritance of Acquired Characteristics
- Changes resulting from use and disuse can be transmitted to offspring
Thomas Malthus
1978 book “An Essay in the Principle of Population”
- In nature, populations increase in size but the amount of resources stay the same
- Competition for resources
Reproductive Fitness
- A measure of success of an individual in the production of offspring across generations
Sir Charles Lyell
Principles of Geology
- Built on Hutton’s work to demonstrate forces of wind, water, erosion, flooding, frost, decomposition, volcanoes, earthquakes etc. and how they produced the geological landscape of today
- Most are slow acting
Charles Darwin
1844 book “Vestiges if the Natural History of Creation”
1859 “On the Origin of Species”
- 5-year scientific voyage on the HMS Beagle 1831
- Galapagos Islands- studied the differences in finches’ beaks
Natural Selection
- All individuals vary
- size, colouration, behaviour, speed, health, prowess, ect. - some of this variation is heritable (passed onto offspring) - All populations reproduce at rates in excess of resources
- Competition for resources occurs among individuals within populations
Therefore favourable traits will be passed to next generation
Speciation
- Later generations become more and more distinct from their ancestor
- Over time new species will appear
Opposition to Evolution (USA) (After ww1)
- After WW1 conservative Christians in the United States wanted to resort to “traditional values”
- Tried to ban the public mention of evolution
- In 1925 in Tennessee a law passed that banned evolution
- This continued in some states until 1968
Bill Nye vs. Ken Ham
- February 4th, 2014 debated the question “Is Creation a Viable Model of Origins”
- Drew significant national attention, more than 3 million live viewers when it happened
- Many scientists feel that even debating this with creationists gives their ideas too much credit and validity
