 Hagedoorn and Hagedoorn (1921) similarly point out that some traits of organisms are “trivial”, i.e., “cannot possibly be accounted for as useful”, such as “the shape and arrangement of small hairs on the seeds of some cereals” (p. 107). They likewise maintain that such traits, which can be stable (“pure”, i.e., fixed) within a species, cannot be the product of natural selection; instead, the Hagedoorns assert, they must be “due to some process which accompanies selection” (p. 108). The Hagedoorns then proceed to describe several ways in which variability in a population can be reduced: a new population is founded which lacks some of the variability of the original population; a population is split in half (with the variability in the daughter populations differing from each other and from the original); and “random sampling” where even though the size of the population remains relatively constant from year to year, only a small fraction successfully reproduce. On this last point, they state,