The most recent type of plant to develop were the flowering plants. Flowering plants were more complex than any other plants that had grown previously, and came to be more diverse than any other plant family. As flowering plants were developing, insects and animals that could pollinate these flowering plants were developing as well. Let's look at a specific example of how this could happen. Birds are flowering plant pollinators.
All birds see colors, but especially prefer red and other bright colors.
A bird looking for nectar would choose brightly colored flowers rather than white flowers, and would choose flowers which are large enough for it to fit its beak into. As the bird feeds on the pollen, pollen sticks to its body and is carried to other flowers. Birds with long beaks would have more success in feeding on nectar that short-beaked birds. Because flowers and their pollinators help each other survive, over time their numbers would increase and they would grow and flourish everywhere. In this example, both the bright colors of the flowers and the long beaks of the birds are adaptations which affected the natural selection of these organisms as survivors.