Doing Science

Epistemic values and an introduction to Evolutionary theory

Epistemic values

From Michael Ruse Mystery of Mysteries (1999): a contrast to cultural values

Promote the "truth-seeking" nature of science

Epistemic values: a good theory should show


What are we trying to explain?

Theory must accommodate these observations

Natural selection as the mechanism


Evolution by natural selection is a consequence of these conditions

  1. potential for rapid reproduction — most organisms can produce more offspring than the environment is capable of supporting
  2. because of condition 1, the availability of resources (food, water, space, light, etc.) will limit the size of the population
  3. where there is heritable variation in traits that influence reproductive success, individuals with those traits should become increasingly predominant in the population.

As a consequence of the three conditions listed above, over a long period of time, the frequency of alleles that result in higher fitness should increase over time.

Note that neither Darwin nor Wallace knew anything about the mechanisms of inheritance.

The precise definition of evolution, according to the modern "Neodarwinian synthesis" is: Change in the relative frequencies of alleles in a population over time. (This definition will make more sense after the third evolution talk.)

If over a long time, populations become so different that they are no longer capable of interbreeding, they are then considered to be different species. This outcome of the evolutionary process is called speciation.