Question

Which of the following was not an anatomic change in the evolution of the Homo line from australopithecine ancestors to Homo erectus?

Options

• Decrease in the ratio of humerus to femur length

• Modifications of the limbs for upright walking

• Increase in brain size from roughly 450 cm³ to roughly 1000 cm³

• Increase in sexual dimorphism

Answer 1

Increase in sexual dimorphism

Explanation:

During human evolution from Australopithecus to Homo erectus:

• There was a decrease in humerus/femur ratio,

• Limb structure adapted for bipedalism,

• Brain size increased significantly.

However, sexual dimorphism (differences between males and females) actually decreased, not increased, males and females became more similar in size and form.