The workings of stage five are far more complex and interconnected than the previous four stages. Instead of killing whole plants and eating them, insect and mammal predators have been engaged to take only portions of a plant and to help the plants in return.
Examples of two early flowering plants (angiosperms), the giant water lily and the magnolia, are looked at to show the intricate relations that they developed with their pollinating beetles. The white, female flower of the giant water lily heats up and emits scent to attract beetles (carrying pollen from previous visits to other flowers), then closes them in for the night while the beetles eat and pollinate the flower. The flower changes sex overnight, and the beetles leave in the morning with pollen for another flower. The flower now turns purple to show that it is male. Though less specific in most other angiosperms, this is a good model of the way that all flowers work with pollinating insects.
This stage has its roots 2 million years ago, while both mammal and flowering plants developed. They began working together with new insects about 100 million years ago, and just before the time of the asteroid impact 65 million years ago, this assemblage grew on about 12% of the land surface.
The impact of the asteroid cleared the stage for the accelerated rise of stage 5. Nonetheless, stages evolve slowly, and life is really quite stable over millions of years. Most of the members of previous stages are still represented today. Some, like the conifers the stage 4, have a big role in far northern climates where the angiosperms do not thrive.
The complexity of stage five is difficult, if not impossible, to encompass. Professor Douglas Tallamy, of the University of Delaware, has been researching the ecological relations of lepidoptera for many years. He finds that, along with other predatory insects, over 90% of nearly 12,000 species of lepidoptera eat specifically one or two genuses of plants. Such close pairing implies a large, complex ecological tapestry. Most songbirds eat exclusively the caterpillar stage of these lepidoptera, and a steep decline in their numbers comes mostly from the non-native ornamental plants that are so loved in American suburbia. These non-native species are now expanding into public lands as invasive species that do not support caterpillars or other players in native ecosystems.
This intricate web of plant predation could be superimposed on another web of pollinators (butterflies and moths generally do not pollinate the same plants that they eat as caterpillars) and another web of seed dispersers. These webs could then be laid over the web of the fungal and plant connections in the soil. The superimposed result would look like the interactome that we have been seeing as the source of the intelligence of bacteria, eukaryotes and plants. There are highly connected plants, like white oaks, and highly connected insects, like generalist bees, that are similar to the hubs in cellular interactomes. The possibility is raised that there may be an interactome on the level of the whole ecosystem. Awareness and decision-making may emerge from it. Some studies have shown decreased competition and increased biodiversity in rich ecosystems. The rainforests of Africa and South America have many times more biodiversity than the northeastern United States. The ecological complexity of such a system is only beginning to be interpreted.
The life of the salmon is described and the ways that these fish bring nutrients from the ocean to the land. Bears near salmon streams show that up to 60% of their nutrients come from salmon, while 18% of the vegetation shows the same source. The systems of the ocean and the land are intimately connected.
Emergent properties of these networks seem to include the biotic pump that carries moisture from the Atlantic Ocean as multiple rainfall events across 1000 miles of the Amazon basin. Regulation of the temperature in the jungle, and the regulation of soil moisture are other cooperative effects. Further emergent properties of these systems surely await discovery.