As it turns out, the spineless and the brave stand up to adversity the same way.
A key protein involved in animals' physiological responses to stress has carried out the same function since before any organism developed a backbone, a study of insects has revealed. That finding suggests that the entire "fight-or-flight" stress-response system based on corticotropin-releasing hormone (CRH) dates back to a common ancestor of vertebrates and insects. It lived at least 700 million years ago.
Mark O. Huising of Wageningen University in the Netherlands, and Gert Flik of Radboud University in Nijmegen, the Netherlands searched the honeybee's DNA for a sequence resembling the vertebrate gene that encodes CRH-binding protein. In mammals and other vertebrates, this substance influences the overall stress response.