>>12435100f1 first generation hybrid, has a full set of chromosomes from each pure parent
f2 second generation hybrid between two f1s, a random mix of genes
imagine one population carried a gene that caused premature heart attack or cancer risk but had evolved another gene that cancelled out this effect, in the f2 there's a high chance of having this illness causing gene but not the gene that cancels it out
the human genome is 3bn base pair long, how many of these do you think exists?
