What is an example of adaptive social behavior

Birds help take care of each other's young to increase their chances of survival, and the behavior is passed on to offspring

i would say it is

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: