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Chapter 13 Test Quiz

Terms in this set (50)

Industrial Melanism: Darkening of populations or organisms over time in response to industrial pollution.

The dark moths have alleles for increased production of melanin (a pigment that makes them dark). However in 1850 dark peppered moths began to appear more often, usually in heavily industrialized areas. The replacement of light moths by dark moths can be formed using Darwin's theory of evolution by natural selection. Dark peppered moths are common in industrial areas where tree trunks are darkened by the soot of pollution. Dark moths are camouflaged on the soot-darkened bark and so are not eaten by birds. Light moths, on the other hand, would stand out against a dark background and would be easy prey for hungry birds.
Late 1950ss H.B.D Kettlewell performed an experiment. He raised populations of light and ark peppered moths in a laboratory. He ten marked the underside of their wings with a dot of paint so they could be recognized later. Next he released light and dark moths in two separate wooded areas of England. In areas that were heavily polluted and the other unpolluted. He finally set traps around the woods to catch the moths and see of the moths matching the color of the tree trunks in each location survived. The graph shows more of the moths matching the color of the tree trunks in each location survived. Hidden observers even saw birds passing by dark moths on polluted tree trunks and attacking the more easily seen light moths. His concluded that natural selection does cause industrial melanism in peppered moths.
Model of evolution in which gradual change over a long period of time leads to species formation. Charles Darwin and his followers believed that the rate of evolution was very slow and that it took millions and millions of years of gradual changes to bring about the evolution of a new species. The concept that evolution takes place continuously, gradually, and over long periods of time. The accumulation of changes can result in the development of a whole new species over time, and this evidence substantiates the theory of this. The agent of change was mutation. This slow divergence of the population through gradual modifications is the hallmark of this.

Model of evolution, in which periods of rapid change in species are separated by periods of little or no change. 1970s a second model for evolution. Adaptions in species arise very rapidly quickly giving rise to new species. These periods of rapid adaptation are interspersed with periods in which little or no change takes place. 1940s some biologists began to challenge the theory of the other model. Fossils of some species remained virtually unchanged over millions of years which conflicts with the concept of the other model. 1972 biologists Niles Eldredge and Stephen J Gould proposed the idea of this model to explain these phenomenon. It describes evolution as a process that occurs in spurts of rapid change that are followed by long periods with little or no evolutionary change. Sudden dramatic mutation brings about a burst of change that quickly creates the new species. The new species is formed the population grows and a new gene pool emerges.