Question

fossils of a long-extinct species have been discovered in both asia and north america. how is this discovery best explained? individuals of this species swam across the ocean from one continent to the other. asia and north america were once connected, but the continents have drifted apart. similar environmental conditions led the species to evolve separately on different continents. when some of the organisms died, their bones drifted across the ocean to the other continent.

Explanation:

• The first option is unlikely as most extinct species wouldn't have the ability to swim across oceans between continents.
• The second option aligns with the theory of continental drift, where continents were once connected (like the Bering land bridge or earlier supercontinents), and over time drifted apart. This would explain how the same species' fossils are found on both Asia and North America as they lived in a connected landmass before separation.
• The third option is incorrect because evolving separately would result in different species, not the same extinct species being found in both locations.
• The fourth option is not feasible as fossilized bones would not typically drift across oceans intact to be deposited in another continent's fossil record.

Answer:

B. Asia and North America were once connected, but the continents have drifted apart.