use strict;
use warnings;

use Data::Dumper;

@populations = qw(mice cats dogs potatoes);
    
my %hash = gener(@populations);    
    
sub gener {    
    my @populations = @_;
    my %HoH;
    for (@populations) {
        my @chroma = (0...10);
        my @chromb = (0...10);
        my @ind = (0...10);
        $HoH{$_} = {
            individual   => \@ind,
            chromasome1  => \@chroma,
            chromosome2  => \@chromb,
        };
    }
    foreach my $population ( sort keys %HoH ) {                        
        foreach my $info ( sort keys %{ $HoH{$population} } ) {            
            print "$population: $info = ",
                join(', ', @{$HoH{$population}{$info}}),"\n";
        }
    }
    print Dumper(%HoH);
    return %HoH;        # returned as list; to returna ref, use \%HoH
}