The term resurrection ecology is used to describe two distinct areas of practice. The first is the hatching of dormant eggs of a still living species at a previous stage of its evolution. The second is the act of bringing a subspecies back from extinction by introducing a related subspecies into the original environment, and letting it evolve naturally.
So far it is the first meaning of this term which has received the most attention in the popular and academic communities. Within the past few years a number of prominent biologists have written papers outlining their experiences and successes with this type of resurrection ecology.
Scientists find dormant eggs in a number of sustaining environments: extreme cold, lake beds, and even small sealed pockets in rock formations. These eggs, so far only of insects and plankton, are brought back to life and hatched in incubators. The results are astounding.
A type of zooplankton, Daphnia retrocurva, has caused the most buzz. Eggs of these tiny creatures have been found from nearly a hundred years ago, and when hatched, the creatures that emerge are distinctly different from the Daphnia retrocurva found today. It is a snapshot of evolution over time, and has helped resolve some long-standing debates in the field of evolutionary biology.
Perhaps even more exciting than the answers that have been discovered through resurrection ecology is one of its practical applications. A problem occurs in restoration work, when the species that originally inhabited a region have evolved so well to cope with the manmade intrusions that they are no longer viable in the restored environment.
Resurrection ecology offers an easy solution to this problem. Where dormant eggs are available, a "version" of the animal from the past can be brought back to life and reintroduced to the restored environment. It is as if we can roll back time, not only by rebuilding the pristine natural surroundings, but by transporting creatures from the past into the present.
The term resurrection ecology is also used to describe a different way of dealing with this same problem. When a subspecies becomes extinct, most often due to the loss of its only habitat, it may leave behind a number of related subspecies, adapted to survive in different environments.
If the original subspecies' habitat is restored, scientists can often use evolution in their favor to recreate the extinct subspecies. By finding a close relative in a slightly different environment, and transplanting that subspecies into the newly restored habitat, ideal conditions are generated to produce a nearly identical subspecies as that which was originally made extinct. While these "new" subspecies are not always exactly the same, the results can be close enough for it to appear to be a true resurrection.