Effect of Precipitation on the Evolution of Finches - Assignment Example

One particular animal, which gained Darwin’s attention, was the finches on the island. It was through studying these finches that Darwin came up with one of the most important terms in evolutionary biology which is one of the driving forces for evolution: natural selection. Natural selection plays into the role that nature selects organisms, which are best fit for the environment. Those that have the traits that give them the best advantage in environmental conditions will survive and proliferate while those who have the inferior traits will not thrive and die out (Darwin, 2010).

In this particular simulation, we were looking at what the effects of precipitation on two separate islands and how it would affect the size of the beak of a species of finches. We can make this hypothesis because we know that the amount of precipitation will influence the different types of flora and seeds, which will grow on the island. This can affect the size, hardness, and shape of the seeds and this will have a direct effect on the size of the beak of the finch that inhabits the island. Our hypothesis was that of non-directionality, meaning that we did not know how precipitation was going to affect beak size in any particular direction, but we knew that the precipitation was going to affect how flora grew on the island, thus this would affect beak size.

Since this was an interactive simulation, very few materials were needed to complete this lab. A computer with an active Internet connection was necessary to use the online simulation software to collect the data because this observational data would be impossible to be collected over thousands of years.

 The first step of being able to run the experiment was to log onto the site to experiment. Next, depending on the experiment, the experimenter has the option to set the variables that they are interested in looking at. For the case of our hypothesis, we are looking at the beak size of precipitation. The independent variable is the initial size of the beaks. The experiment calls for modifying the precipitation on the islands to see if this affects beak size. On one island, move the precipitation to the extreme if there is no precipitation and then on the other island, move the precipitation to the maximum amount of precipitation the island can have. Set the amount of time to look at over three hundred years and run the experiment. Then look at and analyze the data to see if the data matches the proposed hypothesis.

As can be seen from the graph, we have an interaction effect at the start and then both populations diverge from each other as time progresses. On Darwin Island, where the precipitation was observed to be 100.0 cm, there was an increase in beak size as time increased. On Wallace Island, where the precipitation was observed to be 0.0 cm, there was a decrease in beak size as time increased. Based on this result, we can conclude that over 300 years, the amount of precipitation on the island played a role in the physiological evolution of the finches on their respective islands. Because of this, our non-directional hypothesis was correct in that there was an observable change in the beak size when compared to the amount of precipitation. Just looking at the amount of precipitation on the island is not enough to justify the change in beak size. Because it is shown that the amount of precipitation affects the flora and beak size, other factors such as the amount of competition of other finches on the island as well as the size of the island could have the same effect on the size of the beak on the finches.

Based on the data collected from the experiment, it was shown that the data supported our hypothesis that the amount of precipitation on the island has a direct effect on the size of the beaks of the finches living on the island. This shows that at least one environmental factor can result in a drive for evolution. This is also based on natural selection in that nature affected the way the flora grew, which had an inherent effect on beak size depending on the variables in which the seeds were affected.