The fetus has a lower level of than the adult.

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.  

the wetland preservation movement began in the u.s. in earnest with the clean water act (cwa) of 1972. although not specifically written to protect wetlands, the cwa is comprised of a series of regulations designed to prevent pollutants from contaminating u.s. waters.