Efforts to identify the origins of Ashkenazi Jews through DNA analysis began in the 1990s. Currently, there are three types of genetic origin testing, autosomal DNA (atDNA), mitochondrial DNA (mtDNA), and Y-chromosomal DNA (Y-DNA). Autosomal DNA is a mixture from an individual's entire ancestry, Y-DNA shows a male's lineage only along his strict-paternal line, mtDNA shows any person's lineage only along the strict-maternal line. Genome-wide association studies have also been employed to yield findings relevant to genetic origins.