Examining the Evolution of Drosophila melanogaster using Hardy-Weinberg Equation as a Null Hypothesis Austin Rill BSC 2011L Section: 902 10/20/2017 Introduction: Drosophila melanogaster is a model species used commonly for research in the areas of genetics and phylogeny (Kohn and Wittkopp, 2007). Drosophila is a model species due to the abundance of offspring, short generation times, and the ease of identifying wild type vs ebony phenotypes (University of South Florida, 2017, Biodiversity Lab Manual). This experiment is being performed in order to evaluate whether or not a fly culture after 3 generations will conform to the Hardy-Weinberg equilibrium equation. This equation is being used as a null hypothesis and will most likely not be achieved due to the relatively small population of flies …show more content…
Initially, the vials must be made. This includes filling a vial 1/8th of the way with a mixture of food and distilled water. After this there is a fly culture netting is inserted into the vial for the flies to crawl and live on as not to die in the food at the bottom of the vial. The final step for this portion is to plug the vial with either a cotton ball or a plug. Additionally, the flies must be anesthetized before they are observed. To do this an anesthetizing wand must be placed in fly nap, then slid under the plug of the vial. When this is accomplished there is roughly a five-minute wait period until all the flies are anesthetized. When the flies are confirmed to be asleep they can be removed from the vial and counted. After this they must be counted and distributed using five males and five females from each phenotype and placing them into the prepared vial. The number of females, males, ebony, and wild type must be recorded for the experiment and the total fly count should be
The objective of this experiment is to determine what genes are responsible for the white-eye color in two strains of Drosophila melanogaster, known as the common fruit fly. Drosophila is used as the experimental organism for many reasons which include its small size, easy maintenance, short 10 day generation time, and a fully sequenced genome. The characteristics of the wild type, which is the most common phenotype found in nature, include brick red eyes, long wings, gray/tan body, and smooth bristles. Of course, there are mutations that occur that cause specific traits to deviate from the wild-type phenotype. These traits include wing length, bristle shape, body color, and eye color.
Conclusion for class di-hybrid cross: The p value 0.779 is in the non-significant range in the chi square table. The null hypothesis is therefore correct. Sepia eyes and vestigial wings in the flies is a mutation in the genes that is not linked meaning it is a product of independent assortment.
This experiment was designed to illustrate the process of evolution through the use of Origami Birds. It was evident at the conclusion of the experiment that Origami Birds with a smaller in circumference front wing placed 3 centimeters from the end of the straw and larger in circumference back wing placed 3 centimeters from the end of the straw flew further than the Generation 0 birds with the same circumference front and back wings. Our results also indicated that birds with their wings positioned differently than 3 centimeters from either end of the straw did not fly as far as those who were positioned at that 3 centimeter mark. Generation 0's best flyer produced a distance of 2.08 meters with a 3x20 and 3x20 wing ratio. Generation 1's best
They are very popular because they have a relatively short life cycle, which lasts about 9 days. This makes it easy to observe multiple generations in a short period of time. The fly’s life cycle consists of egg, larvae, pupa, and adult stages. At each of these stages of development, Drosophila exhibits different phonotypical identities and mutations. The flies that were crossed contained a genetic mutation called apterous. Apterous can be observed by looking for flied that are missing wings. Flies with apterous will not have any wings. If this mutation is sex linked, it is expected that the male population will only be wingless in the F2 generation. If the mutational is autosomal, it is expected that the mutation to normal fly ratio is
Examining the Crosses Between Drosophila Fruit Flies Introduction The major topic of this experiment was to examine two different crosses between Drosophila fruit flies and to determine how many flies of each phenotype were produced. Phenotype refers to an individual’s appearance, where as genotype refers to an individual’s genes. The basic law of genetics that was examined in this lab was formulated by a man often times called the “father of genetics,” Gregor Mendel. He determined that individuals have two alternate forms of a gene, referred to as two alleles.
We then allowed the larvae to hatch, and counted and recorded the total number of flies, the phenotype, and the sex. After taking down all this information this would allow us to perform a F1 cross, we made sure to examine the flies carefully since we needed virgin flies. We prepared a new vial with the a 1:1 ratio of medium and water. After recording the data of the F1 generation, and picking out the virgin flies for the crossing, and we killed of the rest of the flies using the oil method. After some time passed the F1 generation had larva in the vial. Once we noticed the larva we had to put the flies to sleep and collect the data. We then had to prepare another two new vials and medium and water. Carefully observing the flies and picking out three males and three female virgin flies to place into the new vial. Than killing of the other flies. After about a week we had the F2 generation. This was the most important generation, it was what we were looking for to allow us to observe and compare our experiment to Mendel’s experiment. We were looking for a 9:3:3:1 ratio with our flies. Using a basic Punnett square table and the crossing that we had accomplished our results should have looked like the following Punnett square.
Rienzo, Anna Di. Wilson, Allan. 1991. Branching pattern in the evolutionary tree for human mitochondrial DNA. Evolution 88: 1597-1601.
The purpose of this experiment is to conduct genetics studies using drosophila fly as the test organism. Scientists can study the basic biology that is shared by all organisms using a model organism, such as drosophila fly1. Drosophila fly, or more commonly known as fruit fly, has several qualities that makes it well suited for experimental genetics cross. First, fruit flies are low maintenance organisms. They are small in size (few millimeters long), so they occupy a small space and a lot of them can fit in one vial at the same time. They only require a media to feed on. In this lab, instant media was used, which is efficient as it only requires the addition of water to be used. This media contains ingredients that the fruit fly can feed one,
Robert Warren, Lisa Nagy, Jane Selegue, Julie Gates, and Sean Carroll produced this experiment that wanted to examine homeotic gene expression in butterflies. The hypothesis they tested was do homeotic genes have driven morphological change or do the homeotic genes provide a pre-existing plan where insects segment diversity evolved. The genes Antp, Scr, Abd-A, and Ubx were isolated from a cDNA library and were used to explore differences in limb and wing numbers between flies and butterflies. Where Ubx and Abd-A are expressed, the limb and wing numbers arose. They started to wonder if the expression of BX-C genes were different in butterflies (P.Coeni) and fruit flies (drosophila). When they did tests, they saw that conservation of BX-C and ANT-C homeotic gene expression are fundamentally similar and don’t explain the differences in appendages in each species. They looked into embryogenesis, and at 20% of the embryogenesis of butterflies, they saw Abd-A protein and RNA are expressed in the anterior and abdominal segments. High levels of Antp expression are seen in the thorax. Past the 20% mark of embryogenesis, the patterns seen of Abd-A, DII, and Antp expression differed extremely - no DII or Antp were expressed in the abdominal proleg.
Interestingly, Hawaiian cave planthoppers rank among the highest speciation rates among all animal species, which contradicts the prior assumption of the limited evolutionary potential of obligate cavernicoles. Furthermore, the differentiation between the species is random with regard to cave age and geographic distribution. Overall, the Hawaiian cave planthopper system provides an ideal model for testing models of stochastic effects in evolution in a natural system for several reasons. First, the system is simple enough to allow distinction between different factors affecting speciation rates. Also, the system is essentially a series of populations undergoing “natural experiments” of repeated events under similar conditions, which allows for the assessment of relevant factors. The Hawaiian planthoppers seem to directly challenge the Founder-effect concept by Mayr, which hypothesizes a loss of genetic variation that occurs when a new population ...
According to Klug, &Ward (2009), members of a certain population from another are distinguished by the presence of unique genetic characteristics. It is believed that large populations have greater diversity of alleles, compared to the small populations. In most cases, the diversity of alleles designates a greater potential for any evolution of new genes combination. This also shows greater capacity for evolution in adapting different environmental condition. On the other hand, individuals in small populations are possible to be hereditarily, anatomically as well physiologically more consistently than in large populations.
Web. The Web. The Web. 11 February 2014 “Biology: Evolution”. The New York Public Library Science Desk Reference.
Forensic entomology is the study of insects and arthropods and their relation to a criminal investigation. Forensic entomology can determine the postmortem interval (PMI) or how long since the descendants’ death, whether the body has been moved since expiring, and what injuries may have been sustained (Ryan, 2011). When decomposition begins, insects establish a colony to lay eggs on the remains; these eggs will hatch into larvae that will eat the human organs and tissues. Forensic entomologists can determine the specific insects present in the body and estimate how long a body has been left exposed by examining the stage of development of the fly larvae; however, these findings are not always plausible. The fly larvae look and act different at each stage of development. The time required for stage development is not only affected by environmental influences such as geographical location, climate, and weather conditions, but also by type of insect. The forensic entomologist must consider these conditions when estimating the postmortem interval. Knowledge of insects, their life cycles, and their habits make entomological evidence a priceless tool for an investigation. Forensic entomology has proved its significance in a number of cases; though circumstances such as weather, temperature, and time of year clearly affect the development of insect infestation, and the expert must keep these in the forefront of his/her mind (Innes, 2000).
Zacherl, Danielle. “Biology 171 Evolution and Biodiversity.” National Association of Research in Science Teaching 2007 Annual Meeting, New Orleans LA. (2007):n. page. Print.
The housefly is the most common fly found in our homes. Flies look for food scraps, poo, or anything that is old to eat and lay their eggs on. After laying its eggs, it takes 8 to 20 hours for the egg to become a maggot, or tiny worm. The maggot will stay there and eat the food scraps and poo for about 5 days.