Simple Sequence Length Polymorphisms (SSLPs) are used as

genetic marker A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can ...

s with polymerase chain reaction (PCR). An SSLP is a type of polymorphism: a difference in

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

sequence amongst individuals. 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 Genetic variation is the difference in DNA among individuals or the differences between populations among the same species. The multiple sources of genetic variation include mutation and genetic recombination. Mutations are the ultimate sources ...

between two individuals in a certain species.

Applications

An example of the usage of SSLPs ( microsatellites) is seen in a study by Rosenberg et al., where SSLPs were used to cluster different continental populations of human beings. The study was critical to Nicholas Wade's New York Times Bestseller, '' Before the Dawn: Recovering the Lost History of Our Ancestors''.Wade, Nicholas (2006). ''Before the Dawn: Recovering the Lost History of Our Ancestors''. Penguin Press.

Rosenberg Study

Rosenberg studied 377 SSLPs in 1000 people in 52 different regions of the world. By using PCR and

cluster analysis Cluster analysis or clustering is the data analyzing technique in which task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more Similarity measure, similar (in some specific sense defined by the ...

, Rosenberg was able to group individuals that had the same SSLPs . These SSLPs were extremely useful to the experiment because they do not affect the

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological propert ...

s of the individuals, thus being unaffected by

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...

.{{cite journal , last=Rosenberg , first=N. A. , title=Genetic Structure of Human Populations , journal=Science , publisher=American Association for the Advancement of Science (AAAS) , volume=298 , issue=5602 , date=2002-12-20 , issn=0036-8075 , doi=10.1126/science.1078311 , pages=2381–2385 , pmid=12493913, bibcode=2002Sci...298.2381R , s2cid=8127224

References

Polymorphism (biology)