Skip Navigation
You are viewing an older version of this Concept. Go to the latest version.

Evolution Acts on the Phenotype

Describes how natural selection acts on the traits or characteristics of an individual.

Atoms Practice
Estimated2 minsto complete
Practice Evolution Acts on the Phenotype
This indicates how strong in your memory this concept is
Estimated2 minsto complete
Practice Now
Turn In
Meat Over Mind
Teacher Contributed

Meat Over Mind


Human Carnivory

Student Exploration

Are You Going To Eat That?

The size and sophistication of the human brain, relative to body size, is a hallmark of Homo sapiens and a defining characteristic of the species. But how did we develop these big brains? Various theories exist as to how we accomplished this feat given the energetic requirements of our brains. Some say it was tool-use, some say it was group hunting and some say it was meat itself. None of these ideas are mutually exclusive, they all fit together to some degree. But recent work by scientists indicates that maybe it's all about meat.

Now that you've heard some of the reasoning behind how our diet led to our brains, read about the latest evidence that meat was the key.

Extension Investigation

  1. How is the size of a gut related to the quality (net caloric value in this case) of food? What happens to digestion time when an animal has a large gut?
  2. What organism has tapeworms most closely related to tapeworms in humans? What does this relationship suggest about past behavior of Homo sapiens? Do you find this evidence convincing? Why or why not?
  3. How much more energy does brain tissue use than muscle tissue on a pound per pound basis? What kinds of limitations does this represent for Homo sapiens?
  4. What do some scientists feel is a drawback of eating raw food? On average, how many hours a day does a chimpanzee (Pan troglodytes) chew?
  5. How does cooking meat make it easier to eat? Explain your answer as fully as you can.
  6. Why do scientists feel that understanding the length of time Homo sapiens breastfeed is key to understanding how we've changed over time? How does meat figure into this theory?

Resources Cited

Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Show More

Image Attributions

Explore More

Sign in to explore more, including practice questions and solutions for Evolution Acts on the Phenotype.
Please wait...
Please wait...