Dispersion Lab Write-Up
Introduction:
The purpose of this lab was to determine whether the dispersion of fiddler crab burrows were either clumped, uniform, or random, using Morisita’s Index and a chi-squared test. Fiddler crabs are small crabs, and males are known for having one claw that is much larger than the other one. Fiddler crabs live along sea beaches and other areas close to water, and one can usually determine whether there are many fiddler crabs in an area by looking for their dwellings, which are small holes in the ground where the fiddler crab burrowed. Using Morisita’s Index and a chi-squared test, one can determine whether these burrows that are made by the fiddler crab are either clumped, uniform, or randomly dispersed. Morisita’s Index is a formula that directly tells you whether the dispersion of a population is clumped, uniform, or random.…show more content… If the number is equal to 1, this means that the dispersion of the population is completely random, and if the number is equal to 0, this means that the dispersion of the population is perfectly uniform. As the number gets higher in value towards infinity, the dispersion is more clumped. A chi-squared test does not directly test the dispersion of a population, but instead tests a hypothesis in a similar manner as a t-test. If Χ² > Χ²α, than the data is significant from random. If Χ² < Χ²α, than the population randomly
