Here's why:
* Seed plants are better adapted to dry environments: Seeds provide a protective coating and food source for the developing embryo, allowing it to survive harsh conditions and germinate when conditions are favorable. This is a major advantage over the spores of non-seed plants, which are more vulnerable to drying out.
* Seed plants have a more efficient vascular system: Their vascular system allows them to transport water and nutrients more effectively, which is essential for survival in dry climates.
* Seed plants can reproduce without water: Unlike ferns and mosses, seed plants don't need water for fertilization. They can reproduce using pollen, which is carried by wind or insects.
This shift towards drier conditions, which occurred in the late Devonian and early Carboniferous periods, created an evolutionary pressure that favored the development of seed plants. Over time, seed plants became the dominant plant life form, replacing the previously dominant ferns and mosses.
