Ancient DNA (aDNA) is
Unlike modern genetic analyses, ancient DNA studies are characterised by low-quality DNA. This places limits on what analyses can achieve. Furthermore, due to degradation of the DNA molecules, a process which correlates loosely with factors such as time, temperature, and presence of free water, upper limits exist beyond which no DNA is deemed likely to survive. Allentoft et al. (2012) tried to calculate this limit by studying the decay of
The first study of what would come to be called aDNA was conducted in 1984, when Russ Higuchi and colleagues at the
Double primer PCR amplification of aDNA (jumping-PCR) can produce highly skewed and non-authentic sequence artifacts. Multiple primer,
Single primer extension (abr. SPEX) amplification was introduced in 2007 to address postmortem DNA modification damage.