In order for a species to evolve, there must be some factors put in place. Many question whether natural selection is a way of finding that a population is at the brink of early speciation. We know that evolution, ecology, natural selection, and environment are all related to one another. But, what is it that makes a species what it is? What allows them to inherit certain traits? This paper will focus on the study by Beren Robinson who chose to study the threespine fish of the coastal British Columbia lakes.
The Threespines Sticklebacks
Brenan Robinson chose to study the fish known as the threespine sticklebacks from the Gasterosteus family. He found that they had undergone a rapid period of speciation and that the ones that inhabited the lakes of coastal British Columbia, more specifically those that inhabited Cranby Lake, were among the youngest species on Earth. He believed that no more than two species of a particular fish could occur in any one lake. Judging by what he must have already observed, he came to the conclusion that he needed to compare the different species that had evolved independently of other pairs.
Question and Hypothesis
Robinson had questions about whether or not constraints imposed by distinct environments were responsible for the evolution of the pairs of species that he was finding in the different lakes. He hypothesized that the fish represented certain phenotypes that were products of natural selection, which promoted divergence within the populations. He wondered whether or not divergence could potentially occur when the species face trade offs, which involved different tasks for different species depending on what environment they were in (Smith and Smith, 2009). One of his observations was t...
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...tronger than the other or healthier than the other. If there is a larger number of one species as opposed to the other, then I would wonder about this as well and hypothesize that it could also have something to do with their eating habits.
Conclusion
Brenan Robinson’s study is a good way to look at how morphological differences have occurred with the threespine spicklebacks. These are the kind of studies that open up doors for further research. The questions don’t end where Brenan Robinson’s study ended. There is much more that scientist can take from one study alone. This study is a good study for people in several fields of science and it will probably be studied again with different hypothesis and questions in the years to come.
References
Smith, T. M., & Smith, R. L. (2009). Elements of Ecology (7th ed.) San Fransisco, CA Benjamin
In this entertaining, search into global fish hatcheries, New York Times writer Paul Greenberg investigates our historical connection with the ever changing ocean and the wild fish within it. In the beginning of the book Paul is telling his childhood fishing stories to his friends, that night Paul discovers that that four fish dominate the world’s seafood markets in which are salmon, tuna, cod, and bass. He tries to figure out why this is and the only logical answer he could come up with is that four epochal shifts caused theses wild fish population to diminish. History shows that four epochal shifts happen within fifteen years causing certain fish species populations to diminish. He discovers for each of the four fish why this happened to
http://eaglenet.lambuth.edu/facultyweb/science/biology/RCook/community%20ecologyS10.pdf. Impacts on the Biodiversity. Quebec Biodiversity Website -. Web. The Web.
Darwin: A Norton Critical Edition, Second Edition ; ed. by Philip Appleman; copyright 1979, 1970 by W.W. Norton & Company, Inc.
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.
The second of Tinbergen’s questions Phylogeny looks at the evolutionary explanations of development, as opposed to just how behaviour has adapted, including mutations in response to environmental changes. Some of these mutations remain in species even after necessity has gone, and can influence future characteristics of that species. The third of Tinbergen’s questions looks at Causation,...
In 2000, Dr. Philip D. Gingerich, a paleontologist from the University of Michigan, and his associates discovered two primitive whale fossils in the Balochistan Province of Pakistan. By dating the limestone located in the Habib Rahi Formation of the Balochistan Province, Gingerich estimated these fossils to be about 47 million years old. According to author David Braun of National Geographic News, “The researchers have classified one, Rodhocetus balochistanensis, as a new species of an existing genus, and the other, Artiocetus clavis, as a new species and new genus” (Braun, 5). The discovery of these two fossils suggests that the closest living relative of these primitive whales could possibly be the modern day hippopotamus. This suggested relationship is based on similarities in the bone structure between the two animals.
Purpose: The purpose of this lab is to investigate the various components of different ecosystems in a smaller representation and study the conditions required for the ecosystem’s sustainability as well as the connections between
Charles Darwin’s theory of natural selection explains the general laws by which any given species transforms into other varieties and species. Darwin extends the application of his theory to the entire hierarchy of classification and states that all forms of life have descended from one incredibly remote ancestor. The process of natural selection entails the divergence of character of specific varieties and the subsequent classification of once-related living forms as distinct entities on one or many levels of classification. The process occurs as a species varies slightly over the course of numerous generations. Through inheritance, natural selection preserves each variation that proves advantageous to that species in its present circumstances of living, which include its interaction with closely related species in the “struggle for existence” (Darwin 62).
Mills, Scott L., Daniel F. Doak, and Michael E. Soule. "The Keystone-species Concept in Ecology and Conservation." BioScience 43.4 (1993): 219-25. Apr. 1993. Web. 30 Oct. 2011.
Raven, Peter H., George B. Johnson, Kenneth A. Mason, Jonathan B. Losos, and Susan R. Singer. "Quantifying Natural Selection." Biology. Tenth Ed. New York: McGraw-Hill Companies, 2013. Print. 8 Apr. 2014.
Chapter two consists of Darwin continuing his studies. He talks about variation in the natural world compared to the domesticated species. He defines species variation and says that every naturalist has a different idea of the definition. He explains to the reader that linking other species together by characteristics of variation is challenging because some are so similar but vary in other ways. Environmental conditions could be effecting the variation. Climate, temperature, the separation of the animals could transform them. The species changes over time and have chi...
He realized that snake embryos had bumps where there should be legs. Which mean they probably evolved from a creature with legs. He noticed that whale embryos had teeth, but adult whales did not have teeth. The most shocking of his embryotic studies involved human embryos. He noted that the human embryos as slits around the neck, the same in fish. The difference is that in fish the develop into gills, and in human the become the bones of the inner ear. This showed that humans must be descended from fish. This led him to the conclusion that all species were somehow connected. He theorized that beginning with a common ancestor, species had changed dramatically over generations. Some species may add new body features, or lose them. He called this descent with
Many scientists in the past, such as Aristotle and Plato, believed that there were no changes in populations; however, other scientists, such as Darwin and Wallace, arose and argued that species inherit heritable traits from common ancestors and environmental forces drives out certain heritable traits that makes the species better suited to survive or be more “fit” for that environment. Therefore, species do change over a period of time and they were able to support their theory by showing that evolution does occur. There were four basic mechanisms of evolution in their theory: mutation, migration, genetic drift, and natural selection. Natural selection is the gradual process by which heritable traits that makes it more likely for an organism to survive and successfully reproduce increases, whereas there is a decline in those who do have those beneficial heritable traits (Natural Selection). For example, there is a decrease in rain which causes a drought in the finches’ environment. The seeds in the finches’ environment would not be soft enough for the smaller and weaker beak finches to break; therefore, they cannot compete with the larger and stronger beak finches for food. The larger and stronger beak finches has a heritable trait that helps them survive and reproduce better than others for that particular environment which makes them categorized under natural selection (Freeman, 2002).
Darwin’s observations from the islands made him want to come up with some explanation to why this occurred. He began to do research of each the species that had lived on these islands and observe all of the characteristics that had. He noticed that the islands h...
Verrill, A. E. "Remarkable Development of Star-Fishes on the Northwest American Coast; Hybridism; Multiplicity of Rays; Teratology; Problems in Evolution; Geographical Distribution." The American Naturalist 43.513 (1909): 542. Print.