A Fuller Exploration of the System

Now we're going to change the code to look for the smallest set of digits (all 0s).
You need to do two things.
The first is to change WORST_VALUE at the top. You can just change the comments so that the big number (all 9s +1 is worst).
The second is to change firstIsBetter. Note that there is a warning (a yellow bit on the right) by firstIsBetterSmall. Change firstIsBetter to firstIsBetterLarge and firstIsBetterSmall to firstIsBetter. (The yellow bit should now be on firstIsBetterLarge the uncalled function.)
Now if you run it, you should move toward 0.
It may not get there. You can run it longer and it will.
However, it's all based on randomness, and each time you run it, you get the same random numbers. You can change the seed, right below WORST_VALUE, to get a different set.
You can also play with POPULATION_SIZE, PARENTS_BREEDING, MUTATION_RATE and of course GENERATIONS_TO_RUN to explore. You can even change GENES_IN_MEMBER.
Finally, you can also change it to search for particular digit strings.
In evaluateMember, switch the comments so that you're calling evaluateMemberDistanceFromSearch instead of evaluateMemberSum.
You can also change the searchValue string. (If you pick a number closer to 0 than 90, you need to change WORST_VALUE too.)