Learning Objectives

7.1.1 Summarize the key stages that make up the life history of an organism.

7.1.2 Explain how genetics and the environment act as controls on life history traits.

7.1.3 Compare the benefits and costs associated with sexual versus asexual reproduction.

7.1.4 Describe how additional complexity in a life cycle, such as larval and adult forms, may benefit a species.

Studying variation in life history traits and analyzing the causes of that variation helps us to understand how life history traits interact with the environment and influence the potential growth rate of populations. In order to understand such analyses, it is helpful first to examine some of the broad life history patterns found within and among species.