Is thyroid gland an intelligent design by the designer?

The ductless gland found on both sides of the windpipe secretes the hormone...thyroxine, a compound of iodine and thyrosine, which controls the rate of metabolism in the human body affecting its growth and activity. Lack of thyroxine causes slow development of the body and brain and if it is in excess, causes excitability....Now think....can it be evolved by natural processes...or it is an intelligent design by the designer?