POPULATION GENETICS (FRUITFLY)
NAME: Christopher N. Anah
CLASS: BIOL 2108L
INSTRUCTOR: DR. JAMES BATTEY
OVERVIEW: In this lab the Drosophila melanogaster fly species were used to do genetic test crosses. Students were taught how to manipulate phenotypes, collect data from F1 through the F4 generations, and analyze the results.INTRODUCTION: The basic principles of genetics are very often shared by a vast array of organisms. For that reason, it is usually only necessary to study the genetic structure of a few organisms, in order to gain a general understanding of how it works in many others. Microevolution results due to the changes in allelelic frequencies that occur over time within a population. This type of evolution is calculated by a model used in population genetics called the Hardy Weinberg equation. The Hardy-Weinberg equation allows researchers to determine whether evolution has taken place by adhering to five specific conditions. The law essentially states that if no evolution is occurring, then an equilibrium of allele frequencies will remain in effect in each succeeding generation of sexually reproducing individuals. In order for equilibrium to remain in effect Microevolution must not occur, that is none of the following conditions must be violated: 1. No mutations must occur so that new alleles do not enter the population. 2. No gene flow can occur (i.e. no migration of individuals into, or out of, the population). 3. Random mating must occur (i.e. individuals must pair by chance) 4. The population must be large so that no genetic drift (random chance) can cause the allele frequencies to change. 5. No selection can occur so that certain alleles are not selected for, or against. If even one of these conditions are debasedthan micro evolution has occured. In this lab students were instructed to cause micro evolution in a population of fruit flies “Drosophila melanogaster”. This organism was chosen for a number of different...
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