Well, you could use prototypes to do this.

use Data::Dumper;
sub two_hash(\%\%) {
    my ($genes,$totals)=@_;
    return  { %$genes,%$totals }
}


my %foo=qw(1 2);
my %bar=qw(A B);

print Dumper two_hash(%foo,%bar);
[download]

But I have this horrible feeling that my saying this is like giving a loaded gun to a baby to play with. Don't do it this way until you understand why I have this feeling.

:-)