Chapter 16, Problem 13A

Summary Introduction

To define:

The given vocabulary term

Introduction:

The hominins include humans and all their extinct relatives. They have bigger brains than other hominoids, with more complexity in parts of the brain where high- level thought occurs. The hominin face is thinner and flatter than other hominoids. They have long thumbs and flexible writs that provide them with high level of manual dexterity.

Answer to Problem 13A

Hominins are bipedal, that is they can walk upright on two legs.

Explanation of Solution

When hominins evolved the landscape of Africa was changing and bipedalism was an adaptation to the new savanna environment. Food resources were sparse and far apart. The hominins had to travel long distances. By walking upright they could travel long distances more efficiently.

The area of body exposed to sunlight also reduced due to walking upright and subsequently the area exposed to cooling winds increased.

Bipedal hominins were able to carry objects in a better manner and use their hands for other purposes.

The upright position helped hominins reach fruits on low branches easily as they travelled from tree to tree.