Organisms carry genes that result in certain characteristics when the genes are expressed. The possibilities for an organism to change thus reside in the genes. Animals and plants already have the necessary genes, but can turn them on and off as their surroundings change.
Several fish species can change sex as needed. Other species adapt to their surroundings by living long lives — or by living shorter lives and having lots of offspring. The ability of animals and plants to change can sometimes manifest in apparently extreme ways.
The cuckoo wrass is a fish species that lives in groups with one male and several females. If the male dies, one of the females develops into a new male. This can clearly have obvious advantages under certain conditions.
“Normally we think that the ability to change grows as more changes occur in the life of an average individual. But our research shows that this can work in reverse as well. The greater the ability of an average individual to change, the longer the individual will live,” says Irja Ida Ratikainen, an associate professor at the Norwegian University of Science and Technology (NTNU)’s Department of Biology.