my $gene_length         = gene_length();
...
			if ( defined( $genome{$gene} ) ) {
				push( @phenotype, $genome{$gene} );
...
sub gene_length {
	my @gls = ();
	foreach my $key ( keys(%genome) ) {
		push( @gls, length($key) );
	}
	@gls = sort(@gls);
	if ( $gls[0] != $gls[$#gls] ) {
		die("Invalid genotype");
	}
	return ( $gls[0] );
}