- The NPR article says that scientists were studying the bones of different primates, including humans. Besides humans, can you name some other primates?
- Primates are mammals that include monkeys (such as baboons and howler monkeys), apes (such as gorillas and chimpanzees), and prosimians (such as lemurs and marmosets). Learn more about primates here.
- The scientists in the article studied fossils of humans, human ancestors (such as Australopithecus africanus, Paranthropus robustus, and Homo neanderthalensis), and chimpanzees.
- The scientists discovered that modern human bones were less dense than the bones of other primates. What does this mean? What are characteristics of dense bones?
- Bone density measures the amount of minerals per square centimeter of bone.
- Dense bones are usually stronger and heavier than less-dense bones. Denser bones can withstand more pressure and are harder to break.
- Before the recent discovery, when did scientists think humans developed less-dense bones than other primates?
- Why did scientists think less-dense bone structure developed millions of years ago?
- “Having lighter bones would have made it a lot easier to travel long distances.”
- Today, some scientists think “The change [in bone density] occurred much later in our history.” Why do these scientists think the change happened about 12,000 years ago?
- “That’s right when humans were becoming less physically active because they were leaving their nomadic hunter-gatherer life behind and settling down to pursue agriculture.” Learn more about the development of agriculture here.
- The Hadza, a community in Tanzania, is one of the last societies that live a primarily hunter-gatherer lifestyle. Watch the video on our site or above, showing the diet of a Hadza family. What foods do you see them hunting? What foods to you see them gathering?
- meerkats and other small mammals
- honey (they’re using smoke to get rid of the bees!)
- tubers or other plant roots
- Why would the NPR writer say agriculture-based diets create “wimpy” or “lazy” people?
- She’s joking by saying that less-dense bone structure makes someone “wimpy.”
- She’s making a half-serious point by saying that hunter-gatherer lifestyles such as the Hadza require much, much more physical activity than “lazy” lifestyles whose diets rely on agriculture.
Nat Geo: What is agriculture?
(extra credit!) Proceedings of the National Academy of Sciences of the United States of America: Recent origin of low trabecular bone density in modern humans