GeneticSharp is a fast, extensible, multi-platform and multithreading C# Genetic Algorithm library that simplifies the development of applications using Genetic Algorithms (GAs).
Just answering my question. Yes:
public Population(int minSize, int maxSize, IChromosome adamChromosome)
For 40%, for exp, on a 1000 population:
minSize = 400
maxSize = 1000
Is it possible to select the % of individuals who will survive in each generation?