the ability to change for survival in an environment
Scientist Scott A. Eckert says: "This giant of the sea feeds mainly on jellyfishes. Although a variety of jellyfishes and related prey are abundant, they are eaten by few other vertebrates. As one might suspect, a life spent eating mostly jellyfish requires some special adaptations to make the job easier. The leatherback has sharp cusps resembling a set of fangs on either side of its upper mandible and a single interlocking cusp on its lower jaw. Because of the species' relatively weak jaws, these cusps are essential in shearing chunks from larger prey, such as the lion's mane jellyfish, which may have a bell in excess of three feet in diameter."
the ability to change in size (get older & larger)
Just as scientists can determine historical changes in climate by examining tree rings, Christine Robichaud, a biology student at Mount Allison University in Sackville, N.B., is using the growth rings in turtle shells to predict the danger that global warming poses to the already threatened species.