Genetic Drift Simulator - Follow Up
A few things to point out in retrospect:


There's inconsistent quotation marks everywhere
Lines like the following are confusing and hard to read: print_result += key + ':' + ratioPopulation[key] + ' '
These (throw) should be throw new Error as it includes a stack trace.
Don't use snake case (temp_drawn) use camel case (tempDrawn)
Be careful about using truthy value checks like (population.length % drawAmount != 0) as it can cause issues relating to booleans, for example false == 0 will return true, but false === 0 will return false. See Truthy and Falsy: When All is Not Equal in JavaScript for more information and examples.
run doesn't match the case of the other functions, it should be Run.
k &lt; ratioPopulation[populationName];: declare the length as a variable within the for loop as it gets rid of the constant length checking which can strain when you have a really large array.
You should consider using an array here instead var final = {}; as it may reduce logic on the loops.