What is Junk DNA?
Stretches of DNA that do not code for genes; most of the genome consists of so-called junk DNA which may have regulatory and other functions. Also called non-coding DNA. In genetic testing for ancestry, it is the non coding regions of the yDNA or mitochondrial DNA that is tested. It cannot be used for paternity testing or identification of an individual since many individuals may share the same sequence.
Junk DNA is DNA which does not appear to have any discernible function. However, the term “junk” is a bit misleading, as research on junk DNA has suggested that it may actually play an important role in the evolutionary history and lives of many organisms. Rather than junk, this DNA may in fact be stored for a critical reason, and researchers have started exploring junk DNA with the goal of learning more about it. Some people refer to junk DNA as “noncoding DNA,” referencing the fact that it does not code proteins which express in the host organism’s phenotype. Whatever you call it, the percentage of junk DNA in the genome is often quite high. In humans, for example, 95% of the genome is composed of noncoding DNA. Junk DNA appears to explain a large part of the differences in genome size between different organisms, as some plants and animals have a great deal of junk DNA, while others have less. All sorts of information may be contained in junk DNA. For example, huge sections of nonco
