It is common in the field of population genetics to use estimates of a population's genetic variability as a measure of its ability to adapt to selective pressures in a changing environment. Daphnia , it is possible to gather information about the amount of genetic diversity harbored in natural populations using both quantitative and molecular techniques. In the spring of 1992, an unusual system of about thirty dune ponds was discovered near Florence, Oregon that contained these Daphnia , providing an ideal system for investigating the amount of genetic variability maintained between and within ponds.
Most Daphnia are cyclical parthenogens.
Natural populations are composed of females who clonally reproduce until conditions within the pond deteriorate. At that point, males are produced as well as haploid eggs, which are then fertilized and give rise to resting eggs. In ponds which dry completely, annual recruitment is entirely from the ephippia, which can survive as long as ten years prior to hatching. The ponds found at Florence also dry completely each year and require annual recruitment from ephippia. Furthermore, because the coastal winds constantly move the sand, they are transient and do not reappear in the same spots year to year.