Drosophila Lab Abstract

In a large, randomly mating population where mutations, migration, and natural selection are no longer viable, the allele and genotypic frequencies will remain at equilibrium. If any of these conditions are changed, then the allele and genotype frequencies will be unable to maintain genetic equilibrium.

According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.

From the data we can conclude that different traits or parameters can effect a population in many different ways. It can decrease or increase a population depending on the trait. After a hurricane hits Lake Malawi the cichlid fish male population must adapt to the new factors that have been put upon them. Mutation within the population supports the fact that it can cause dominant and recessive allele frequency to decrease. Migration causes the allele frequency to lower as well due to movement of the population after the hurricane. The cichlid male fish with a higher fitness are more suitable for their environment, but when their fitness is lowered, their allele frequency decreases. This

Throughout this experiment a number of random and procedural errors were apparent; these errors could have affected the results of the experiment in a number of ways. One experimental error that occurred during the experiment was that some flies became stuck in the food source and died. The main cause of this was the fact that the fly vials were stood up (vertically) before the flies had fully recovered from the anaesthetic. This could be overcome in future experiments by ensuring that the vials are kept horizontal until all of the flies fully recover from the anaesthetic.

86% of the F1 generation had to be killed due to the selection against them. These plants had ten or less trichomes. 14% of this population contained more than ten trichomes and were allowed to cross-pollinate to create an F2 generation. This population resulted in a larger percentile of hairy plants. It went from 14% to 40%. Only 60% f this population were bald. These results proved Darwin's Theory of Natural Selection which is significant because it allowed us to test his theory using artificial selection. Darwin's theory was present among populations whose heritable traits were passed on through generations and the traits that were not useful to the species would slowly fade out due to this theory. In the case of this experiment the plants with ten or more trichomes were more suited

The parents are both homozygous. The homozygous dominant would represent the wild type. And the homozygous recessive would represent the other fly parent of a different strain. The F1 generation would consist of 100% Wild Type but they would all be heterozygous in carrying the recessive gene.

The Evolution Lab simulates environmental situations to determine effects on evolution over periods of time. This lab experiments with the evolution of finches on two different islands over 100, 200, and 300 years. By manipulating parameters that influence natural selection, the effects that natural selection have on the evolution process can be studied.

To set up this experiment, two twenty-five gallon aquariums, 3 petri-dishes, 200 flies, rotten bananas, and yeast were used. The bananas chosen to be an accelerant for the growth of the yeast and were frozen so they would be easier to cut. The yeast was used because the drosophila melanogaster prefer this as a food source.  The vestigial and wild type flies were sexed (to determine their sex), sorted, and counted.  An initial population size of 100 total flies was decided so that it would be easier to determine the phenotypic percentage of the total population. Fly paper was placed in one of the sets of cages to impose a method of natural selection as well as the sexual selection which is being solely tested by the other set of cages.

It would be expected that the mutant F1 flies would be heterozygous for the allele responsible for the grounded trait. If two F1 flies were mated, the percentage of flies that would be expected to be wildtype in the F2 generation would be 25% mutants given that the mutant allele (ap) is predicted to be recessive and, leaving 75% to be wildtype (ap+).

Heterozygotes, which have the wild type phenotype, have normal sight which gives them the advantage of finding a mate and have a better success with attracting a mate with their courtship song (Kyriacou et al, 1978). The male heterozygous Drosophila had a better advantage at mating than the homozygotes, which were the ebony, and therefore we predict there will be more wild type by the end of the experiment.

we said goodbye and placed them in the fly morgue. We allowed the F2 larval

One reason is that, due to their short lifespan, it is possible to evolve many generations of fruit flies in a relatively short time period. Genescient’s, a biotech company, evolved Drosophila over 30 years, which represents about 800 standard generations of fruit flies. To evolve mice over a comparable number of generations would take about 200 years. This gives accurate results.

In most kitchens the small flies that are found are Drosophila Melanogaster also called fruit fly. They are often brought in by ripened tomatoes, grapes and other perishable items from the garden. Drosophila melanogaster is a little two winged insect about 3mm long two winged insect that belongs to the Diptera, the order of the flies. The drosophila egg is about half a millimeter long. Fertilization takes about one day the embryo to develop and hatch into a worm-like larva. The larva eats and grows continuously, after two days as a third in star larva; it moults one more time to form an immobile pupa. Over the next four days, the body is completely remodeled to give the adult winged form, which then hatches from the pupal

This experiment looks at the relationship between genes, generations of a population and if genes are carried from one generation to another. By studying Drosophila melanogaster, starting with a parent group we crossed a variety of flies and observe the characteristics of the F1 generation. We then concluded that sex-linked genes and autosomal genes could indeed be traced through from the parent generation to the F1 generation.

Allele frequency is a measure of the relative frequency of an allele on a genetic locus in a population; which is usually it is expressed as a proportion or a percentage ("Allele frequency," 2014). In population genetics, allele frequencies show the genetic diversity of a species population or equivalently the richness of its gene pool ("Allele frequency," 2014). The frequencies