What is the main evolutionary innovation presented by nematodes? What is the advantage of that innovation?
The main evolutionary innovation of nematodes is the complete digestive system, with two openings (mouth and anus). Since the ingestion and the defecation processes can occur in different extremities of the digestive tube, beings with a complete digestive system have the advantage of ingesting new food while residuals of already eaten food are still inside the body and not yet eliminated.
