What are the oldest living animals in the world?

Scientific studies of elkhorn coral (Acropora palmata) in the Caribbean and off the coast of Florida show that coral genotypes can survive longer than expected. Genotype refers to the genetic makeup of an organism.

Scientists are now using a genetic approach to estimate the ages of corals. The method determines when a coral egg and sperm originally met to form the genome of a coral colony. The researchers then track the number of mutations that have accumulated in the genome since that time. Because mutations tend to arise at a relatively constant rate, researchers can estimate the approximate age of the coral genomes in their study.

These studies can help clarify how corals will respond to current and future environmental changes. Though corals can be resilient and live for thousands of years, elkhorn corals are listed as threatened under the U.S. Endangered Species Act. The corals have suffered recent population declines, indicating that there are limits to how much change even these resilient creatures can handle.