Beside which, while there remain easy adaptations in a confined range, evolution will continue by small, fitness-rich changes. The phylogenic boundary for all life forms on Earth say, is the freezing or boiling point of water, or the vacuum of outer space, which no large life forms can penetrate. Above limits exist for modern, highly adaptable life. There were periods in our evolutionary past when dry land, cold, night, or the air could not be penetrated by large life forms, within the restricting phylogenic boundaries that then existed. The oceans are huge, but if enough varieties of water-life evolve, eventually that environment will saturate .
Creatures can still penetrate the shorelines, and then onto land.
A similar analogy applies to mammals. The nighttime niche might appear as an open range ecologically, but to penetrate it new technologies are required to stay active through the dark, colder hours. Peripheral niches offer a certain protection to creatures that do penetrate them, in that removed from the direct line of fitness-rich competition, low yield fitness gains have a better chance to mature as complex new novelties. In the new theory then, there are only two essential processes different from conventional theory. Evolutionary changes form two broad categories of being either easy, or hard to enact.