$population = regenrate_population();
...
sub regenrate_population {
    my $new_population = [];
    for my $i ( 0 .. ( $population_size - 1 ) ) {
        my $chromosome1 = get_nonrandom_chromosome();
        my $chromosome2 = get_nonrandom_chromosome();
        $$new_population[$i] = get_child( $chromosome1, $chromosome2 );
    }
    return $new_population;
}