Introduction What's the problem? Examples of animals adapting to the environment have been known as far back as the case of the black peppered moths of England in the mid-1800s. In that case, entire populations of the black peppered moths were observed to change color in response to changes in their environment. More recently, bacteria have been known to develop resistance to antibiotic drugs, insects have developed various forms of resistance to insecticide, and plants have adapted to accommodate higher levels of heavy metals in the soil and water. The problem is that it is difficult to locate the genes that stimulate adaptation for three reasons: 1. Traits must be identified based on how they affect fitness and their ecological relevance. In other words, we need to find a trait that clearly makes a difference in whether or not the animal survives. 2. It is challenging to analyze phenotypes when there is little information known about genes. With the moths, nobody knows which of the moth's genes are responsible for the changes in color, so a genetic analysis is extremely difficult to do. 3. Most fitness-related traits are a mixture of many genes. This makes it hard to pin down the adaptations as a result of the actions of one gene. So where do the mice come in? Dr. Nachman's research explores the connection between genotype and coat color in four populations of rock pocket mice. Rock pocket mice live in rocky habitats in the southwest U.S. and northern Mexico. In the 1930s, classical studies revealed that there was a close correlation between the color of a mouse's coat, and the color of the rocks the mouse lived on. Light-colored mice... ... middle of paper ... ...is mice, the alleles did not appear to be responsible for any changes in coat color. The similarity between coat color of the dark mice at Pinacate and the dark mice at Armendaris is probably due to convergent evolution. The Armendaris mice probably evolved the same adaptation (dark coat color) through a separate genetic mechanism. An interesting research project might be to determine the genetic basis of adaptation in the Armendaris population, and make comparisons. Any such results would be enormously useful in showing how evolution affects individual genes. References Nachman, Michael W. Hope E. Hoekstra, Susan L. D'Agostino. "The genetic basis of adaptive melanism in pocket mice." www.pnas.org/cgi/doi/10.1073/pnas.0431157100. Feb. 26, 2003. Purves,William K., et al. Life: The Science of Biology Sixth Edition. Massachusetts: Sinauer Assoicates, Inc. 2001.
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.
An adaptation is the characteristic of an organism that makes it likely to survive. There are three types of adaptations: structural, physiological, and behavioural. Structural adaptations are physical features, physiological adaptations are related to the internal body functions, while behavioural adaptations refer to how organisms respond to stimuli (Beavis 2014). This paper will discuss some adaptations that help koalas and eucalyptus trees survive in their environments.
They evolved into 2 different species by many factors in nature. The factors include genetic drift, mutation, natural selection, and etc. Genetic drift involves the bottleneck effect and the founder effect. I hypothesize that a bottleneck effect took place in the island that the rodents were living in. A natural disaster must of happened and the rodents that had high fitness survived. Therefore since one population survived, that makes them two separate species. I also hypothesize that there was a founder effect in the population of the rodents. A small portion of rodents migrated to Nevis island and reproduced. When this happened this created a whole new population of rodents. Another reason that they could have been 2 different species can be due to gene flow. Some rodents could of migrated to Nevis island.
The idea of the project was to experiment breeding Drosophila Melanogaster (fruit fly) to figure out if certain genes of that species were sex linked or not (autosomal). A mono-hybrid cross and di-hybrid cross was performed. For the mono-hybrid cross, white eyed female and red eyed male were placed in one vial for them to reproduce. For the di-hybrid cross, red eyed and normal winged flies and sepia eyed and vestigial winged flies were placed in their vial to reproduce. In the mono-hybrid cross the results expected were within a 1:1:1:1 ratio. Expected results similar to the expected desired null hypothesis proposed with what the F1 parental generation breeds. The potential results would have had to have been within the ratios of 9:3:3:1. The results were clear and allowed the null hypothesis to be correct. The white eyed gene in the fruit flies is sex linked. Sepia eyes and vestigial wings are not sex linked and are examples of independent assortment.
Audesirk, Teresa, Gerald Audesirk, and Bruce E. Byers. Biology: Life on Earth with Physiology. Upper Saddle River, NJ: Pearson Education, 2011. 268-69. Print.
Some individuals have developed different traits to help them in the process of intra-sexual competition. The organisms with more distinctive traits have greater reproductive success. More genes of those traits are then ‘selected’ and are passed onto the offspring of the organisms. Throughout time variability in these traits becomes
Furthermore, the grey squirrel’s color and size are distinctive traits that separate it from other species. First of all, coloring stays the same when it comes to males and females. Its hue ranges from pale grey to dark grey (Fischer, Lawinczak, Pagad). Its ears, underparts, and tail are all white to pale grey. Ginger-colored fur can be found on this squirrel’s head, hips, feet, and underparts (Lawiczak, Pagad). A natural occurrence among the grey squirrel is melanism, meaning it has an elevated amount of melanin in its pelt (Fischer, Lawinczak, Pa...
Evolution in general, is a hard concept to grasp. There are multiple factors that effect the outcome a species, for example: genetics, nurture, nature, and the environment all play an important role. It was once said that species do not survive due to the fact that they are the strongest or the most intelligent, but because that species is the most responsive to change.
1) Chaplin, G. Jablonski, N. “The Evolution of Human Skin Coloration.” Journal of Human Evolution 39 (2000) 57-106
environments. Evolution is the idea that while organisms exhibit certain traits, they are not fixed and are able to be altered through progressive adaptation. Adaptation occurs through the passing of traits from an organism pa...
Work Cited Colby, Chris. A. Web. " An Introduction to Evolutionary Biology." 28 August 2015.
In textbooks, adaptation, specifically biological adaptation, is usually defined as the method an organism adopts to better survive in its environment and reproduce. In scholarly papers, however, adaptation isn’t always as simple as that. An adaptation can be a structure that gives advantage to an organism over other similar organisms, or a behavior that helps the organism survive in its environment against predators. Sometimes even the adaptation itself wasn’t originally intended for its current biological role, or how it is used in the organism’s environment; this adaptation is sometimes called preadaptation (Kardong, 2006). Because it is difficult to identify which structures are adaptations and which are preadaptations, there is much controversy over the subject in the scholarly world. Often it is helpful to study these adaptations in ancient animals, but as most of these are extinct, scientists can only gather information from their close relatives, and even these aren’t conclusive enough.
more than half the variation was found to be due to heredity. Among these traits were
Sikes, Roberts. and William L. Gannon. "Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research." Journal of Mammalogy 92.1 (Feb. 2011): 235-253. Academic Search Premier. EBSCO. Web. 5 Oct. 2011.