Question

Which evolutionary change took place during the Devonian period?

Animals began to become endothermic instead of ectothermic, allowing for the evolution of mammals.
Fishes began to move to living on the land as tetrapods, which were likely amphibians.
Amniotes began to separate from amphibians, as their eggs evolved protective membranes.

Answer 1

The correct evolutionary change that took place during the Devonian period is:

Amniotes began to separate from amphibians, as their eggs evolved protective membranes.

During the Devonian period, which lasted from approximately 419.2 to 358.9 million years ago, one of the significant evolutionary changes was the emergence of amniotes. Amniotes are a group of vertebrates that includes reptiles, birds, and mammals. One key characteristic of amniotes is the presence of eggs with protective membranes, known as amniotic eggs. These eggs allowed amniotes to lay eggs on land, reducing the dependency on water for reproduction.

This evolutionary adaptation was crucial because it freed amniotes from the need to lay eggs in aquatic environments like their amphibian ancestors. It provided better protection for the developing embryos against desiccation, allowing amniotes to occupy a wider range of habitats, including arid environments. The development of amniotic eggs was a crucial step towards the subsequent evolution of reptiles, birds, and mammals, which are all amniotes.