Early Ancestors Walk Upright
Humans belong to the primate family of mammals, sharing traits like large brains and forward-facing eyes with monkeys and apes. Millions of years ago, a new branch called hominins appeared in Africa, distinguished by bipedalism, the ability to walk upright on two legs. This 6th grade history skill from Chapter 1 of IMPACT California Social Studies introduces students to human evolution and explains how walking upright freed early ancestors' hands for tool use and other activities, setting the stage for the development of human civilization.
Key Concepts
Humans belong to a group of mammals called primates , which also includes monkeys and apes. Primates share special traits like large brains and forward facing eyes that help them understand their environment.
Millions of years ago, a new branch of the primate family tree appeared in Africa. These were the first hominins , the group that includes modern humans. The most important change for these early ancestors was the ability to walk upright on two legs, a skill known as bipedalism .
Common Questions
What is bipedalism?
Bipedalism is the ability to walk upright on two legs. It was the most important physical change that distinguished early human ancestors (hominins) from other primates. Walking upright freed the hands for carrying food, using tools, and performing other tasks essential for survival.
What are hominins?
Hominins are the group of primates that includes modern humans and our direct ancestors. They first appeared in Africa millions of years ago and are distinguished from other primates primarily by their ability to walk upright on two legs (bipedalism).
Why is walking upright important in human evolution?
Walking upright was important because it freed the hands for carrying objects, making tools, and performing complex tasks. It also allowed early humans to see over tall grass on the African savanna, travel long distances more efficiently, and eventually develop larger brains.
Are humans primates?
Yes, humans are primates, a group of mammals that also includes monkeys and apes. Primates share traits like large brains relative to body size, forward-facing eyes for depth perception, and flexible hands. Humans are distinguished by bipedalism and exceptionally large brains.
Where did the first human ancestors appear?
The first human ancestors (hominins) appeared in Africa millions of years ago. Scientists have found the oldest hominin fossils in East and South Africa, leading to Africa being called the cradle of humanity. From Africa, early humans eventually spread across the entire world.
When do students learn about early human ancestors?
Early human ancestors are covered in 6th grade world history at the beginning of the year. The IMPACT California Social Studies textbook discusses this in Chapter 1: Early Humans and the Agricultural Revolution, where students learn about primates, hominins, and the evolution of bipedalism.