Editing Molecular phylogenetics (section)

==Techniques and applications==
Every living [[organism]] contains deoxyribonucleic acid ([[DNA]]), ribonucleic acid ([[RNA]]), and [[protein]]s. In general, closely related organisms have a high degree of similarity in the [[molecular structure]] of these substances, while the molecules of organisms distantly related often show a pattern of dissimilarity. Conserved sequences, such as mitochondrial DNA, are expected to accumulate mutations over time, and assuming a constant rate of mutation, provide a [[molecular clock]] for dating divergence. Molecular phylogeny uses such data to build a "relationship tree" that shows the probable [[evolution]] of various organisms. With the invention of [[Sanger sequencing]] in 1977, it became possible to isolate and identify these molecular structures.<ref name="Sanger75">{{cite journal |vauthors=Sanger F, Coulson AR |title=A rapid method for determining sequences in DNA by primed synthesis with DNA polymerase |journal=J. Mol. Biol. |volume=94 |issue=3 |pages=441–8 |date=May 1975 |pmid=1100841 |doi=10.1016/0022-2836(75)90213-2 }}</ref><ref name="Sanger1977">{{cite journal |vauthors=Sanger F, Nicklen S, Coulson AR |title=DNA sequencing with chain-terminating inhibitors |journal=Proc. Natl. Acad. Sci. U.S.A.|volume=74 |issue=12 |pages=5463–7 |date=December 1977 |pmid=271968 |pmc=431765 |doi=10.1073/pnas.74.12.5463 |bibcode = 1977PNAS...74.5463S |doi-access=free }}</ref> [[DNA sequencing#High-throughput methods|High-throughput sequencing]] may also be used to obtain the [[transcriptome]] of an organism, allowing [[Phylogenetic inference using transcriptomic data|inference of phylogenetic relationships using transcriptomic data]].

The most common approach is the comparison of [[homologous sequence]]s for genes using [[sequence alignment]] techniques to identify similarity. Another application of molecular phylogeny is in [[DNA barcoding]], wherein the species of an individual organism is identified using small sections of [[mitochondrial DNA]] or [[chloroplast DNA]]. Another application of the techniques that make this possible can be seen in the very limited field of human genetics, such as the ever-more-popular use of [[genetic testing]] to determine a child's [[Parent|paternity]], as well as the emergence of a new branch of criminal [[forensics]] focused on evidence known as [[genetic fingerprinting]].