1. The Hardy-Weinberg Principle

2. Modern biologists’ definition of “evolution” = the change in genetic makeup (or gene pool) of a population over time. What’s a gene pool? = the frequency of each of the alleles within a population.

3. Hardy & Weinberg (two mathematicians) G.H. Hardy Wilhelm Weinberg - Developed the Hardy-Weinberg Principle  in large populations in which only random chance is at work, allele frequencies are expected to remain constant from generation to generation.

4. What does this mean?

5. For Example:

6. What causes evolutionary change? Any of the following 5 factors that cause a change in the allele frequencies: 1) Natural selection – favours the passing on of some (advantageous) alleles over others. 2) Small population size – increases likelihood of genetic drift. 3) Mutation – introduces new alleles to a population. 4) Immigration or Emigration – introduces or removes alleles in a population 5) Horizontal gene transfer – the gaining of new alleles from a different species (i.e. Conjugation in bacteria).

7. The Elephant Problem