Data Collection

1. Turn in Evolution Webquest to tray!Warm-Up: On page 5 answer ques.1. Why does natural selection not affect individual organisms? 2. How do elements of natural selection result in differential reproductive success? 3. How does natural selection and adaptation relate to the diversity of the species? Mechanisms of evolution

2. Data Collection

3. Mechanisms of Evolution

4. How Populations Evolve Populations Evolve…Individualsdonot! • Populations evolve because of changes in allele frequencies due to the evolutionary forces that act upon them. • Hardy-Weinberg Principle—frequencies of allele in a population change due to 5 forces: mutation, gene flow, nonrandom mating, genetic drift, and natural selection. HW Equillibrium

5. What is a Mutation? • Changes in DNA nucleotide sequence • Occur infrequently—1 to 10 times per 100,000 cell division—so only affect evolution over long period of time. • Not all mutations change phenotypes, so not all will impact evolution. • Mutations are a source of variation, so it can lead to evolution.

6. What is Gene Flow? • The movement of individuals to or from a population—migration—move alleles into and out of a population. • Introduces new alleles into a population and increases variation. Gene Flow

7. What is Genetic Drift? • Frequency of allele is greatly changed by chance / random event—more pronounced in a small population • Often occurs with natural disasters • unlucky beetles 

8. The model shows a demonstration a student prepared using black and white marbles to show how populations of organisms can change. Which of the following concepts is best illustrated by this demonstration? a. Evolution of a predatory species b. Genetic drift accompanying natural selection c. Environmentally induced genetic mutation d. Immunity from virulent microorganisms 5.

9. Recombination • The production of gametes in meiosis and sexual reproduction produces a wide variety of genetic possibilities. • This provides variation among organisms and increases diversity.

10. Non Random Mating • Some individuals prefer to mate with others that live nearby or have a similar phenotype. • Who would you choose to mate with ladies??? Comparing random and non-random mating

11. Natural Selection • There is variation in traits.For example, some beetles are green and some are brown. • There is differential reproduction. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do. • There is heredity. • End result:The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues, eventually, all individuals in the population will be brown.