First, we want to talk about “why” we need new plants. In the normal course of evolutionary development species come and go. Generally, the timeframe is so long that we either do not notice the change, or we see the change happening but are unable to stop or change things. An example is the disappearance of species of plants or animals in our world. We know that in prior evolutionary history of the Earth, there were once dinosaurs. And then they disappeared. We speculate about why and how and when that extinction actually took place, but we don’t usually dispute that it happened.
Currently, there are many environmentalists and concerned people who want to try to protect the polar bears, or the elephants, or particular species of rare plants and prevent them from going extinct. In reality, they will all go extinct no matter what we do, eventually.
But what if we can assist species to adapt to the changing conditions on our planet so that rather than die out completely, they can change in order to withstand the new conditions? In fact, this is what has always happened throughout the long history of our planet. The plants that we eat now were once what we would call weeds. The grains we cultivate now, thousands of years ago were Johnson’s grass or quack grass. But over time, and with the help of human beings these “weeds” slowly adapted to be more palatable, more nutritious, nutrients more readily available, more resistant to unfavorable conditions, etc.