Chapter 41, Problem 8TYU

Summary Introduction

To analyze: The evolutionary concept of “decent with modification” showing the respiratory and digestive path of mammals with the imperfect anatomy that causes chocking of food in mammals.

Concept introduction: In humans, the digestive tract starts from the mouth then to the esophagus and then the respiratory tract opens up from the nasal opening to the trachea. At the point of the pharynx, the two paths share a passage, where mistiming of entering food and gas causes chocking.  The chocking of food while the food and air intersect in their path explains the imperfect anatomy of the pharynx.