NATURAL SELECTION AND GENE FREQUENCY WHAT IS THAT

NATURAL SELECTION AND GENE FREQUENCY

WHAT IS THAT? • Natural selection is a key mechanism of evolution. • It is the process in which individuals with certain heritable traits survive and reproduce at higher rates than other individuals without those traits. • These traits allow them to adapt to various environmental pressures, favoring their survival and • Gene frequency demonstrates the occurrence of an allele compared to other alleles of the same gene in a population. • The Hardy-Weinberg Principle states allele frequencies will remain the same through generations in a population: with

The Natural Selection Experiment The Hardy Weinberg Experiment Purpose: The natural selection lab aims to simulate the process by which biological traits become more or less prevalent in a population that has a changing environment. The natural selection lab will also attempt to show the relationship between predators and prey. Purpose: To create a population and demonstrate how consistent Hardy-Weinberg's principle really is. To observe the survival rates in genotypes and phenotypes of a population over a span of 6 generations. Hypothesis: We predict that the predator will naturally pick out the prey that is most contrasting in color to its Hypothesis: Since there are mutations, certain allele frequencies will decrease dramatically due to the

SPECIMENS & MATERIALS The Natural Selection The Hardy Weinberg Experiment Specimens: • 40 small colored paper dots which represent the prey • One clawed and double clawed predators that Materials: the species. • kill 1 plastic cup for the “dead” dots • 2 distinct fabric mats which represented different environments for your dots Specimens: • Red, white, and black beads which represented alleles. Materials: • Red beads were used to represent red alleles. • Black beads were used to represent black alleles. • White beads were used to represent white alleles. • 6 cups to place different allele combination in.

NATURAL SELECTION METHODS 1. Provided by the instructor, obtain one of the bottles of colored dots and gather 40 paper colored dots of one color per each individual in your group. 2. The instructor will then provide a fabric board that will serve as an “environment” for your species. 3. Place your colored species around the board in any order. Next, designate a predator for each group and send them to another environment where they will simulate the killing of a species by “eating them” for an allotted time set by the instructor. 4. After the event has occurred, calculate

NATURAL SELECTION RESULTS

NATURAL SELECTION ANALYSIS The different colored dots represented the genetic variation between species. We predicted that those species that stood out from their environment were less likely to survive. Those species that adapted to their environment over • Predators play a role in enforcing evolution and natural selection time had a better chance at survival. because they choose which populations survive and which do not. Those species newly introduced thrive because the predators are not yet familiar with them as shown in the previous slide the newly introduced dark green dots thrived more than any of the other populations. • When a population is brought into a new environment their

HARDY WEINBERG METHODS Case 1 -2 1. Gather all materials and count out 50 white 2. 3. 4. 5. 6. beads and 50 red beads. Put the red and white beads into a single cup so that the beads will mix. Have 3 separate cups available for your RR, Rw, and ww bead combinations. Have a member of the group randomly grab two beads at a time and put the appropriate bead combinations into its corresponding cup. Once the team member has randomly picked all the beads, have someone count and record on your excel document how many of each combination was acquired. Depending on which case you’re doing have a team member calculate the amount of white

GENE FREQUENCY RESULTS: Mutation Effects

GENE FREQUENCY RESULTS: Population Percent

GENE FREQUENCY ANALYSIS Our hypotheses were validated because the mutations affected allele frequencies significantly. The positive mutations led to an increase in population % whereas the negative mutations lead to a decrease in population %. Also, new species • In this population, the red allele is dominant while the white allele is emerged with the introduction of the recessive. The dominant phenotype of red is selected for, represented black allele dominant producing. Rw. favored by the homozygous dominant RR and heterozygous This phenotypes black andits dark red. favored trait is passed on to more offspring, ofincreasing allele frequency. • In both cases of 67% survival and 0% survival of the white allele, its frequency decreased dramatically over time. However, we see that it is almost impossible to eliminate the recessive alleles because of the heterozygous Rw genotype that codes for the favored phenotype.

• Natural selection can increase HOW ARE THEY the frequencies of alleles if they are RELATED? advantageous to a species survival and reproductive abilities. If they somehow produce a phenotype that is not a selective advantage, their frequency will decrease. • The change in allele frequencies is one way of defining evolution. A population evolves as “better” alleles increase in frequency in the gene pool. • This means that gene frequency and natural selection go hand in hand. They affect one another directly because the frequency of a gene makes it better suited for natural selection, while simultaneously, natural selection chooses which genes are

WORKS CITED Campbell, Neil A. , and Jane B. Reece. Campbell Biology. San Francisco, CA: Benjamin Cummings, 2011. Print. Darwin, Charles. "On The Origin of Species. " The Origin of Species by Charles Darwin. Usenet Newsgroup, n. d. Web. 17 Feb. 2015. Photo Credits Darwin’s Finches: http: //www 1. northbrook 28. net/~pamendelson/Mrs. _Mendelsons_Site/Natural_Selection_Classification_files/shapeimage_3. png Colorful Chromosomes: http: //genetics. thetech. org/sites/default/files/Kary. Color. gif Natural Selection Banner: http: //i. ytimg. com/vi/a. Tfty. Fbo. C_M/maxresdefault. jpg Hardy Weinberg Penguins: http: //i. ytimg. com/vi/o. G 7 ob-Mt. O 8 c/maxresdefault. jpg NS Cartoon Fish: http: //media-cache-ak 0. pinimg. com/736 x/1 d/d 1/34/1 dd 13452486 e 4 fd 130930 d 50 d 2 acbb 53. jpg Gene Frequency Goats: http: //farm 7. staticflickr. com/6128/5916685986_f 891 ba 6255. jpg Natural Selection Birds and Beetles: http: //uedata. berkeley. edu//media/3/52571_evo_resources_resource_image_380_original. gif All other photography were done by SCC Biology 3 Students