The present invention relates generally to novel, selectable hybrid polypeptides useful as agents for the treatment and prevention of metabolic diseases and disorders which can be alleviated by control plasma glucose levels, insulin levels, and/or insulin secretion, such as diabetes and diabetes-related conditions. Such conditions and disorders include, but are not limited to, hypertension, dyslipidemia, cardiovascular disease, eating disorders, insulin-resistance, obesity, and diabetes mellitus of any kind, including type 1, type 2, and gestational diabetes.