But they are quoted here from perl - these backticks would go to the SQL engine. Recently I've switched to PostgreSQL so I can't check it but perhaps MySQL uses them for quoting fields with spaces in them.
In SQL, 'foo' is a string. "foo" is a quoted identifier. In MySQL, 'foo' is a string, and "foo" is also a string. So they made the identifier quotation mark the backtick, resulting in `foo`. MySQL isn't SQL :(