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With different controlled environments, the experiment targets to note the difference in the size of beaks and the difference in population throughout 100, 200 or 300 years. The primary tool used in this biological experiment was a specially programmed computer application (automated) that enables the adjustment of variables from default figures. When run, accurate results on the changes in the biological structures of living organisms were shown. These results are therefore used to justify the hypothesis.
In the first experiment, the birds evolve smaller beaks when the independent variable (precipitation) is adjusted to higher levels. This is because when rainfall is high, the seeds become softer, and the birds slowly adjust to the changes of nature until they fully adapt. On the other hand, when rainfall is low, the seeds become harder, and the need for additional force to crack the roots arise based similar principle; the birds evolve stronger and larger beaks over time (Sober, 2008). This adjustment may not favour some birds as the adaptation and evolution process is gradual and, therefore, may lead to the death of individuals unable to adjust effectively to the changes of nature.
When essential parameters that influence natural selection, such as precipitation, are manipulated (adjusted to 50cm/year and 0cm/year on Wallace Island and Darwin Island, respectively), it is noted with great significance that only a few individuals can survive and continue reproducing in an environment with low precipitation. This is because of the variation in biological and environmental factors that are very significant for natural selection. Therefore for 300 years, these changes will influence the evolution of Finch beaks and, in turn, affect their population. This fact can be justified by the graphs and tables drawn below.
The experiment aims to express biological and environmental factors that influence evolution by natural selection and simultaneously simulate how changes in beak size and other parameters on the Finch population affect the growth of beak size and other population numbers. It is concluded that an increase in clutch size will result in a population decrease. More generally, environmental setup variations result in organisms' adjustment or mutation to better fit that environment. In turn, selective pressure is created.