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Gene Frequency and Natural Selection Team Brainstormers (BS) Spring Feb 2015.

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Presentation on theme: "Gene Frequency and Natural Selection Team Brainstormers (BS) Spring Feb 2015."— Presentation transcript:

1 Gene Frequency and Natural Selection Team Brainstormers (BS) Spring Feb 2015

2 Gene Frequency ∗ Random genetic mutations occurs ∗ Inherent Variation ∗ Sexual reproduction Relationship between Gene Frequency and Natural Selection Natural Selection ∗ Influences from the surrounding environment ∗ Eliminating incompetent individuals ∗ Does not produce perfect organisms ∗ Highly selective and specific (According to Hardy-Weinberg, changes in frequency will not occur in a population if these five conditions are not met.) 1.No mutations 2.No natural selection 3.Very large population 4.Random mating 5.No gene flow

3 ∗ Different populations of prey ∗ Different predators ∗ Adaptation by prey and predators ∗ Different environments ∗ Natural disaster-bottleneck effect ∗ Different rates of survival and reproduction of prey populations Natural Selection Methods

4 Gene Frequency Methods ●A starting population of 50 individuals represented by 100 alleles (beads) were picked out of the cup at random; this essentially signifies random mating. ●Allele pairs were added or removed based on the rate of survival to replicate the introduction of selective pressures. ●The allele pairs were then counted and beads were added depending on the rate of survival and reproduction for each case. ●Beads were picked out in pairs at random again, these signify individuals of the second generation. ●This process was repeated for six generations for all runs except for one case due to a shortage of beads. ○That run was carried out until the fourth generation; therefore, all comparative analysis can only be carried out to the fourth generation and forecasting was used for the subsequent generations. ●The rates of survival and reproduction for our various runs are greatly exaggerated, with rates rare- if ever found in nature. ○The exaggeration is so that we can see the explosive/depressive effects of adaptability, or lack thereof, to a given environmental condition.

5 Gene Frequency Results ●According to the graph, each of the genotype frequencies remain constant, therefore reinforcing the fundamental points outlined in the Hardy Weinberg principle.

6 ●This graph entails the projections of the genotype frequency percentages up for future generations.

7 Natural Selection Results First Environment Second Environment Population Size Data G1G2G3G4G5G6 Blue202840281213 Light Purple203340372840 Orange203540 11 Yellow2032403210 Green2016201600 Pink20211316913 Dark Purple2029402499 Aqua00002024

8 ●The second figure displays the combined representation of all of the species ●According to the first Figure (Populations with Projected Decay), the population counts in the first 6 generations fluctuated, but mainly had decreased in numbers.

9 Gene Frequency vs. Natural Selection ●Selection against one genotype can result in an overall positive effect on others by freeing up resources such as food and habitat. ●Fluctuations within subsets of a population are normal, overall change in allele frequency is usually gradual unless a subset completely dies out.

10 ★ Natural selection and allele frequency are closely related, if natural selection is in action, then allele frequencies are changing. ★ The correlation between natural selection and gene frequency can be modeled in the laboratory using simple non-living systems, in living systems with much greater complexity, and can probably be modeled using highly sophisticated computer programs. ★ The allele frequency of the previous generation determines the phenotypic distribution of the current generation. ★ Natural selection acts upon this generation to refine the positive traits, weeding out the negative traits due to selective pressures such as predation, sexual selection, and relative fitness. ★ Therefore natural selection is a direct cause of allele fluctuation within a population. Conclusions

11 ●Reece, J. (2011). Campbell biology Jane B. Reece... [et al.]. (9th ed.). Boston: Benjamin Cummings. ●The Paleontological Research Institution and its Museum of the Earth. Types of Natural Selection. NY. Paleontological Research Institution. [cited 2015 Feb 19]. Available from http://bivalves.teacherfriendlyguide.org/ ●Philip McClean. Evolutionary Genetics [Internet]. Bison (ND): North Dakota State University; 1997 [updated 1998; cited 2015 Feb 25]. Available from: http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen4.htm http://www.ndsu.edu/pubweb/~mcclean/plsc431/popgen/popgen4.htm ●"Modern Theories of Evolution: Hardy-Weinberg Equilibrium Model."Modern Theories of Evolution: Hardy-Weinberg Equilibrium Model. Available from: http://anthro.palomar.edu/synthetic/synth_2.htm References


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