what is the meaning of this phrase? "A larger population is required if no mutation is used, in order to ensure that the necessary building blocks are present in the crossover"

if true
  % code
end

Answer 1

[Niklas Nylén]

It sounds like you are using an evolutionary algorithm. After deciding which individuals to "mate", the population, i.e. number of individuals, is not large enough to be able to get all the needed pieces of information necessary to create the next generation. You should either increase your population size or introduce mutations which would select the missing information randomly.