Chapter 5-6 Summary and Analysis

When the Beagle arrives, Darwin decides to stay on in the area of Bahia Blanca. He finds the fossilized skeletons of huge animals, all within a 200 square yard area. He argues modern large animals live in Africa off of fairly sparse vegetation, and this may have been the conditions in ancient South America as well. An assumption has been made and passed from text to text that large animals need lush vegetation, but Darwin believes this to be wrong.

Darwin turns to the birds, starting with how the ostrich swims long distances. The ostrich generally lays eggs in a group, but sometimes single eggs can be found. These do not hatch. Male ostriches tend the nest and will attack men on horseback if they come too close. From the gauchos Darwin learns several females will lay their eggs in...