Hi, 
This is a statistics question! I hope you may help me ! 
On a DNA sequence region, there are several mutation hits. I want to know if the hits distribution follow or not a random distribution. 
In other words, imagine a target dart. How can get a p-value, to know if darts has been throw randomly or not . 

![Exemple][1]


  [1]: https://framapic.org/2fsQ36tnHGKL/LU4FryMZ2IDU.png
Both distributions are random, with the number of variants in a region as a discrete random variable. The opposite of random is deterministic, which would mean that the number of events is fixed, which is obviously not what you mean. Your second example shows a **uniform** distribution of events, while the first case should look like a deviation from uniform distribution, such that you would look for a test for deviation from uniformity. See here: https://stats.stackexchange.com/questions/25827/how-does-one-measure-the-non-uniformity-of-a-distribution
The simplest test proposed here is a Chi-square test.