Reviewed by Carl Zimmer
Many plants grow a thick coat around their seeds. The coat, called an elaiosome, doesn't do the seed any good, at least directly. Its immediate job is to attract an insect known as the winnow ant. (The photo here shows winnow ants discovering blood root seeds.) The eliaosome releases fragrant odors that lure the ants, which carry the seed into their nest. There they gnaw away at the coating but spare the seed. The ants then carry the shucked seedback out to the forest floor, where it germinates.
The winnow ants thus act like gardeners, protecting the seeds from predators that would destroy the seeds, while also spreading them far from their parent plant. Remove winnow ants from a forest, and its populations of wildflowers will shrink.
As a resident of the northeastern United States, I always assume that all the magnificent examples of coevolution must be going on somewhere else. The jungles of Ecuador, the Mountains of the Moon--these are the places where nature-film producers go to find species exquisitely adapted to each other. This, of course, just belies my far-less-than-complete education in natural history. While reading Dr. Eleanor's Book of Common Ants, I discovered that winnow ants are abundant in New England, along with the rest of the eastern United States. The next time I am out on a walk in the local woods, I'm going to keep an eye out for these elegant little insects.
Dr. Eleanor's Book of Common Ants is itself an elegant little book--and an instructive example of how ebooks can become a tool in the growing citizen science movement. "Citizen science" typically refers to research that relies not just on a handful of Ph.D. researchers, but also on a large-scale network of members of the public. Birders have been doing citizen science for over a century, and now the Internet enables people to collaborate on many other projects, from mapping neurons in the eye to folding proteins to recognizing galaxies. Many of these projects yield solid scientific results (see this paper in Nature, with over 57,000 co-authors as an example). They also provide a new way for research to draw non-scientists into their world.