If It Ain't Broke

Resource for Grades 9-12

| Citation

Media Type:
Video

Running Time: 1m 24s
Size: 8.1 MB

Source: The Human Spark: "Becoming Us"

Learn more about The Human Spark.

Resource Produced by:

Collection Developed by:

Collection Credits

Collection Funded by:

Major funding for The Human Spark is provided by the National Science Foundation, and by the Alfred P. Sloan Foundation. Additional funding is provided by the John Templeton Foundation, the Cheryl and Philip Milstein Family, and The Winston Foundation.

Related Resources:

To Make a Spear
(Video)

As their brains evolved to become larger, early humans developed an innovative tool – the stone hand ax. The hand-ax was created about 1.6 million years ago to butcher large animals. Hundreds have been found in an excavation site in Kenya. Once the basic design was established, people in Africa continued to use the hand ax for over one million years. The fact that the tool changed so little in over one million years leads paleoanthropologist, John Shea to believe the tool was effectively designed for its purpose.

Permitted use:

Download and Share

Accessibility Features: Transcript

Discussion Questions

1. Why does archaeologist John Shea believe the design of the hand ax changed so little for so long?
2. What does he mean by “powerful natural selection?”
3. How does the expression Shea uses in the video, ‘If it ain’t broke don’t fix it’ relate to the previous phrase he used?

Print Discussion Questions

Transcript

ALAN ALDA (NARRATION) With bigger brains came new abilities. One of the earliest and most enduring examples of our new-found skills was the invention, about 1.6 million years ago, of stone hand axes, probably used to butcher large animals.

Hundreds were found at this site in Kenya.

Once they were invented the basic design didn’t change, and people went on making them in Africa for over a million years.

JOHN SHEA What that tells me as a scientist, it tells me that tool is not under powerful natural selection. There’s nothing pushing the people to make different tools. It’s a tool that’s adequate to its task and they don’t need to change it. We have saying where I’m from, if it ain’t broke, you don’t fix it.

ALAN ALDA (NARRATION) John Shea is one of the leading experts on stone-age technology – and remarkably adept at creating stone tools using the same techniques as our ancestors. In real time a hand axe takes him about ten minutes.

It’s a pretty basic tool, yet our ancestors kept making it, generation after generation—for perhaps 50 thousand generations. In some ways it marks a very early sign of our brains’ new abilities. But in others, it also points out how far we still had to go.