How plants affect the evolution of animals
The very base of the food chain is occupied by plants, which use sunlight directly. These primary producers then become nourishment for the primary consumers, and indirectly for all other organisms, up to the top predators.
The fact that plants are at the base, implies that almost all other living beings depend on them, as well as the course of their evolution.
This is also due to the fact that the generational turnover of plants is extremely long compared to that of the vast majority of animals, and therefore the mutations, and their relative spread in a population is much slower, and it wouldn’t be able to keep up and react to the evolution of the consumers. Indeed, the very opposite is true: it is other animals that generally adapt to plants.
The different varieties of plants become different kinds of food for which different species specialize (like browsing and grazing herbivores).
The amount of plant biomass also regulates the size of the populations of all other organisms: constant rainfall and abundant light, which is what plants need, make the tropics an ecosystem teeming with highly diverse life forms, while at the poles the lack of sunlight supports far fewer herbivores (both in terms of species and population) and even fewer carnivores.