my $str = "((mouse,rat),(human,chimp))";
my $str2 = "(mouse,(human,chimp))";

##</code><code>##

my $aoa = [['mouse','rat'],['human','chimp']];
my $aoa2 = ['mouse',['human','chimp']];

##</code><code>##

my $str = "((mouse,rat),(human,chimp))";
$str =~ s/\(/\[/g;
$str =~ s/\)/]/g;
print "$str\n";

my $aoa = eval($str);