Question

which statement describes a difference between the continents on earth as scientists think they existed 540 million years ago and their existence today?
the continents were located mainly in the southern hemisphere 540 million years ago; today they are distributed throughout both hemispheres.
the continents were influenced by underlying convection currents in the mantle 540 million years ago; today this factor is no longer an influence.
the continents were moving 540 million years ago; today they no longer move.
the continents were devoid of life 540 million years ago; today they are full of living organisms.

Explanation:

• Plate tectonics theory indicates that continents were mainly in the Southern Hemisphere 540 million years ago in a super - continent called Gondwana. Today, continents are distributed throughout both hemispheres. Mantle convection currents still influence continents' movement today, and continents are still moving due to plate tectonics. Also, life was present on Earth 540 million years ago (Cambrian period).

Answer:

The continents were located mainly in the Southern Hemisphere 540 million years ago; today they are distributed throughout both hemispheres.