Chapter 8: Primate Life Histories and the Evolution of Intelligence

Chapter Outline

1. Big Brains

1. Natural selection does not allow features that are costly to maintain unless they confer an adaptive advantage.
2. The investment made in a morphological feature is linked to the benefit obtained from the investment.

2. Life History Theory

1. Fundamental trade-offs constrain reproductive options.
2. A juvenile phase allows an organism to sexually mature.
3. When organisms age, fertility declines.
4. Strong selection exists against deleterious alleles that affect the young.
5. Early reproducers are small, have large litters, and have high rates of mortality.  Late reproducers are larger, have small litters, and have lower rates of mortality.

6. Primates are late to reproduce and have low rates of mortality, large brains, and long life spans.

3. Why Did Primates Evolve Large Brains?

1. Competitive pressures produced by sociality
2. Need to successfully exploit feeding niches
3. Need to eat foods that require complex processing techniques
4. Need for behavioral flexibility and innovation
5. How can we test these hypotheses?
• By determing neocortex ratio
• By assessing ecological factors related to intelligence
• By studying the executive brain ratio

4. What do monkeys know?

1. They have knowledge of relationships that they aren’t directly involved in.
2. They understand kinship relations within their group.
3. They understand dominance hierarchies and rank relationships.
4. They can predict what others will do and adjust their behavior accordingly.

In This Chapter

The Norton Gradebook

Instructors now have an easy way to collect students’ online quizzes with the Norton Gradebook without flooding their inboxes with e-mails.

Students can track their online quiz scores by setting up their own Student Gradebook.

Go to the Norton Gradebook

Norton Ebooks

The ebook version How Humans Evolved, Fifth Edition, offers the full content of the print version at half the price. The Norton ebook format replicates actual book pages for a pleasant reading experience and allows students to take notes and highlight with ease, print pages as needed, and electronically search the text.

Norton Ebooks

Links

Norton Website
College Books
Professional Books
Trade Books
Help Desk

About W. W. Norton

W. W. Norton & Company has been independent since its founding in 1923, when William Warder Norton and Margaret D. Norton first published lectures delivered at the People's Institute, the adult education division of New York City's Cooper Union. The Nortons soon expanded their program beyond the Institute, publishing books by celebrated academics from America and abroad. By mid-century, the two major pillars of Norton's publishing program—trade books and college texts—were firmly established. In the 1950s, the Norton family transferred control of the company to its employees, and today—with a staff of 400 and a comparable number of trade, college, and professional titles published each year—W. W. Norton & Company stands as the largest and oldest publishing house owned wholly by its employees.