# Thread: Probability of Mutation

1. ## Probability of Mutation

The probability of a mutation happens is 10^-8.

In a genome with 3*10^9 positions, what is the probability of it happens at least once, and the probability of it happens in a specific position of the genome ?

2. Originally Posted by deadlock
The probability of a mutation happens is 10^-8.

In a genome with 3*10^9 positions, what is the probability of it happens at least once, and the probability of it happens in a specific position of the genome ?

The distribution of the number of mutations is binomial with mean $30$ and sd $\approx \sqrt{30} \approx 5.5$.

So $1/2$ a mutation is $\approx 5$ sd below the mean, so the probability of $0$ mutations is essentially $0$.

RonL

3. Originally Posted by CaptainBlack
The distribution of the number of mutations is binomial with mean $30$ and sd $\approx \sqrt{30} \approx 5.5$.

So $1/2$ a mutation is $\approx 5$ sd below the mean, so the probability of $0$ mutations is essentially $0$.

RonL