Simple Sequence Length Polymorphisms (SSLPs) are used as genetic markers with polymerase chain reaction (PCR).
SSLPs are repeated sequences over varying base lengths in intergenic regions of deoxyribonucleic acid (DNA).
Variance in the length of SSLPs can be used to understand genetic variation between two individuals in a certain species.
[2] The study was critical to Nicholas Wade's New York Times Bestseller, Before the Dawn: Recovering the Lost History of Our Ancestors.
These SSLPs were extremely useful to the experiment because they do not affect the phenotypes of the individuals, thus being unaffected by natural selection.