Inheritors of the Earth

When most people think of biodiversity, they think of saving the species we already have. While that's important, there are other ways that nature adapts to change. Chris D. Thomas discusses them in Inheritors of the Earth: How Nature is Thriving in an Age of Extinction.

We are currently living in an Anthropocene Age, where the Earth is markedly affected by our actions. Many people say that due to human activity, we are currently living through a sixth mass extinction. Thomas, however, turns conventional thinking about biology upside down. Instead of removing invasive species and preventing them from hybridizing with local ones, we should move endangered plants and animals to locations where they are likely to thrive. Although there are cases where invaders out-compete native species, this is because the invaders are fitter. For examples, island birds may lose the ability to fly over time. For them, flying is a waste of energy (since they have no predators) that could be better used for reproducing. When predators come, the birds can't escape, and they may be less able to fight new diseases. Mainland birds that have had to deal with challenges constantly are better able to survive in this situation.

Moving new species to different locations can create new niches in the ecosystem and give rise to hybrids that can form new species. One of the examples discussed in the book is an invasive plant that offered butterflies a new source of food at a time when their normal food source was threatened. When the apple tree was brought to America, it allowed a type of fly to specialize in a different food source, ultimately splitting off to form a new species. This new apple fly has three specialized parasitic wasps associated with it, so the apple tree brought about the development of four new insect species. These developments can happen fairly quickly, over a couple of centuries instead of millions of years.

Thomas ultimately reminds us that we humans are a part of nature, so everything we do is natural. Since the dawn of civilization, we have developed new species by selective breeding and brought others with us on our journeys. Global travel is creating a second Pangaea. Change has been part of life since the first unicellular creatures came into existence (and they brought about a mass extinction by releasing oxygen into the air). We should not try to recreate some long-lost Eden, but try to preserve as much biodiversity--genes--as possible, no matter in what type of body they reside or what types of technology we need to use.

As a science fiction writer, I find these ideas intriguing. Often, future worlds are depicted as being either all city or an ecological wasteland. Thomas offers alternatives. Camels and mammoths roaming the American Southwest, anyone? Science fiction writers should also think about the implications of colonizing a new world. Will Terran life forms be able to hybridize with otherworldly ones? If so, what would be the result?

Do you have a particular endangered species that you love--or a common one that you love to hate? Feel free to share them in the comments.