NOTES: GENETIC DRIFT Objective: What is genetic drift and how does it affect the diversity of a population?

Title Box 1: What is genetic drift?  Changes in a small population’s allele frequency due to random chance  Not based on fitness its about luck

Title Box 2: What causes genetic drift?  Natural disasters: hurricanes, volcano, tsunami, earthquakes, fire, etc.  Random Events: stepped on, ran over, picked up, etc.

Title Box 3: What are the types of genetic drift? Founder’s effect: part of the population immigrates to and colonizes a new area Bottleneck effect: a disaster happens leaving few survivors from an original population

Talk it Over and Write it Down: Look at the population of cats before and after. 1)What do you notice happen to the phenotypes? 2)What happened to genetic diversity? 3)What type of genetic drift happened? Title Box 4: Quick Write DIE in flood

Title Box 5: What does genetic drift do to a population?  Decreases diversity within a population  Affects small populations

Genetic Drift WS 1.Roll dice put dot next to that # worm 2.Example roll 3 put dot next to worm 3 3.Roll 5 more times (total 6 times) 4.Color the next generation worms those colors with dots 5.Repeat until you get to generation 4

Title Box 6: Exit Ticket At the bottom of today’s notes answer the following questions in complete sentences: Explain how genetic drift affects the diversity of a population. How does this affect the fitness of the population?

What is genetic equilibrium?  When allele frequencies remain the same  No change means no evolution

What are the conditions for genetic equilibrium? 1. Random mating 2. Large population 3. No immigration/ emigration 4. No mutations 5. No natural selection