Red, brown, and some green algae exhibit alternation of generations. All land plants exhibit alternation of generations. No charophytes (stoneworts) exhibit alternation of generations. Keeping in mind the recent evidence indicating charophytes are the sister group to land plants, we can infer .

The evolution of the land plants occurs directly from the green algae that perform alternation of generations

Explanation:

Charophytes are a type of green algae that are present in freshwater. It is considered that the terrestrial planets such as Embryophyta are developed within the charophytes. So the lands plants are directly evolved from the green algae and thus show the alternation of the generation. Such type of life cycle of the plants in which the sexual process is completed into phases such as the sexual phase and the other in the asexual phase is known as alternation of the generation.

The atmosphere wasn’t strong enough to contain more oxygen when compared earths atmosphere today, the exosphere was full of rips and couldn’t contain enough oxygen to provide for land creatures, although aquatic earthlings could continue i exist in this environment