The Devil Lake Trout Population Study

Genetic diversity allows the population to adapt to changing environments and it contributes and adds to the gene pool.

Figure 3. This graph depicts the average allele frequency of male cichlid fish when the change of fitness in the homozygous dominant (AA) and the homozygous recessive (aa) are decreased to 0.5 and 0.6 based on their ability to find food sources after the hurricane hit. The average value over five trials is shown to be 0.496.

This occurs when a species is separated and mate with a different species, changing their genetic composition, if then the two species were to be brought back together and mate again, it would cause what is called ‘gene migration’. This process gives so many different variations among the species, which allows more and more variation and population. This process also explains endangered species and extinction.

This study was undertaken in order to compare the heterozygosity of three Lake Trout populations at various loci. Samples of twenty-five Lake Trout were collected from three lakes: Devil, Eagle and Loughborough, all three of which are situated north of Kingston, Ontario. An autoradiograph was used to analyze the genotypes of the individuals at six different loci of microsatellites, which are repeat sequences in the DNA that are neutral and do not code for proteins. This data was used to compare the genetic diversity of the three different trout populations. Numerical

Natural sources of variation include: mutations, gene flow, and genetic shuffling. Mutations are random changes in DNA that result in beneficial, harmful, or no changes in an organism. Gene flow can also be referred to as migration. It is the exchange of genes of individuals from one population to another. Genetic shuffling occurs in meiosis when alleles switch to create new combinations of genes. The steps of natural selection are overproduction, variation, competition, and selection. Overproduction is important because it keeps the species from becoming extinct and allows for more variation in offspring. Variation is what can either help the organism have a higher chance of surviving or could lower the chance of surviving.

Genetic diversity provides a species with its form and function. A species genotype refers to their genetic code; what their cells are going to be used for – hair cell, eye cell, muscle cell, etc. A species phonotype refers to the way in which that species gene will be expressed – blonde hair, blue eyes, large muscle tone; which significantly impacts the success of that individuals genes. Without genetic diversity among populations the gene pools would be very limited, which gives way to a rise in mutations and inevitably the end of a species. “Genes regulate body size, shape,

The blue crab Callinectes sapidus is a wide-ranging, ecologically and economically important species along the Atlantic and Gulf of Mexico (GMx) coasts of North America. Consequently, its basic biology, life history, population genetics, and demography have been the subjects of numerous studies. For my dissertation research, I propose to focus on two critical areas concerning the ecology and evolution of blue crabs that have broader implications for our understanding of marine organisms with biphasic life cycles. For the first chapter I will investigate the unusual finding of extreme temporal and spatial variation in the genetic composition of settling blue crab larvae along the Texas coast. Since it was reported in 1993, this finding been

The purpose of this conservation assessment is to provide land managers and the general public with an overview of the distribution and status of common trout (brook trout Salvelinus fontinalis; brown trout Salmo trutta; and rainbow trout Oncorhynchus mykiss) on the Grand Mesa, Uncompahgre, and Gunnison National Forests (hereafter, GMUG). Common trout species are part of a suite of Management Indicator Species (MIS) “…which are monitored during forest plan implementation in order to assess the effects of management activities on their populations and the populations of other species with similar habitat needs which they may represent (Forest Service Manual 2620.5).” MIS assessments are revised every five years and each is a synthesis of the most recent field-based observations and peer-reviewed science pertaining to the species.

For instance, the Itaipu Reservoir on the Paraná River in South America is a man-made cistern that utilizes hydropower for the area in the form of dams and reservoirs. When the reservoir inundated the Guaira Falls which served as an ecological filter separating most species, fish that had lived in the lower part of the Paraná River gained access to the upper Paraná River (Vitule, 2012). In order to quantify homogenization, Vitule employed Jaccard’s coefficient which measures similarities between species in the same community. From the data, he concluded that homogenization occurred in the area not by the elimination of threatened species but by the unidirectional movement of fish. More than half of the species in the upper Paraná Basin were distributed from the lower Paraná Basin after the reservoir flooded. Thus, homogenization and consequent loss of biodiversity of the Itaipu area was directly influenced by anthropogenic

However, it must be considered that a population already well adapted to the laboratory environment may experience outbreeding depression when elevated recombination rate is coupled with significant outcrossing. I speculate that outbreeding depression will not be observed in these short-term experiments with the wild isolates but will likely be observed in the N2 strain. Among the wild isolates, I predict that the elevation of recombination rate will allow the population to adapt more quickly to the environment, resulting in an increase in fitness after 100 generations, and this effect will be proportional to the rate of outcrossing. Dissecting the role of a changing environment and the degree of initial local adaptation are areas that could be explored as extensions of this

Genetic diversity in a population is the genetic variability in the genotype of species. It serves as a way for a population to adapt to an evolving environment because more variation allows species to survive in natural selection (“Introduction To Genetic Diversity,” n.d.). This can be assessed in various ways such as counting the allele frequency per loci, using chi-square to analyze “the differences among loci and breed,” testing for “Hardy-Weinberg Equilibrium” between gene and genotype frequencies and calculating the average heterozygosity (“Measuring Genetic Diversity,” 2011, p23-25). Also, measuring the nucleotide diversity in a population is not only another way of assessing genetic diversity but it allows researchers to determine the causative

To simulate the introduction of genetic drift, selection, and non-random mating into a population, www.virtualbiologylab.org, specifically the PopGen Fish Pond was used. This simulator allows experiments to be conducted online without the need of anything tangible besides a computer. The website specifically describes the simulator as “simulating natural environment with the way life responds to changing conditions”. Within the simulator, parameters and conditions can be adjusted to model the population with the forces accordingly. For this experiment, parameters were set as follows: initial size-50, carrying capacity-50, rr-1, Rr-0.5, RR 0.5, strength of assortment-0.6. The remaining parameters were left as they were set by the simulator.

In most sexually reproducing species, individuals will have different alleles to each other but have the same genes, the combination of all the possible alleles in the population is known as the gene pool. There is variation in alleles and phenotypes within the gene pool of a population due to segregation, independent assortment and crossing over between homologous chromosomes during meiosis causing the offspring to be genetically identical to its parents. In nature different environmental factors act as selection pressures for organisms and over time traits that are beneficial to the organisms survival will be selected for an increase in allele frequency, this process is known as natural selection.

The populations are expected to follow Hardy-Weinberg Equilibrium; therefore allele frequencies will not change from one generation to the next. However, this was not the case. The smaller population will followed non-directional genetic drift, while the larger population followed natural selection, a directional change from generation to generation. This is seen in the chi-square probability distributions, where although the small population’s probability is considered non-significant the chi-square value was only 0.211 (Table 1) less than the significant chi-square value. The small population allele frequency (p) was non-directional and varied greatly between groups and generations (Figure 1). The large population chi-square value was noticeably larger and was affected more than the small population (Table 2). The large population shows a much more directional change toward wild-type flies. The large population allele frequency (p) was directional and followed a general pattern between groups, where by the last generation the frequency (p) had increased from the original, 0.5 (Figure 2). Genetic drift drift typically behaves differently in each population, as seen in the small population (Figure 1), while the results of natural selection are consistent from population to population, as

The way genetic diversity is defined is by probability, from the same population two random alleles are chosen, that is how they determined the genes (6). The total amount number of