Changes

One surprising finding to come out of the earliest studies in comparative genomics was just how genetically similar most species are.  This finding led to a major paradigm shift (spawning, in its wake, the field of [[evo-devo]]), and, after much research, revealed for the first time the major molecular (that is, genetic) mechanisms of evolution<ref>Gilbert (2006).  ''Developmental biology''.</ref>.

One surprising finding to come out of the earliest studies in comparative genomics was just how genetically similar most species are.  This finding led to a major paradigm shift (spawning, in its wake, the field of [[evo-devo]]), and, after much research, revealed for the first time the major molecular (that is, genetic) mechanisms of evolution<ref>Gilbert (2006).  ''Developmental biology''.</ref>.

Some of the most highly conserved genes (that is, genes with the least variation between species) are the genes encoding for ribosomal RNAs (rRNA).  Comparing rRNA sequences allows investigators to infer the evolutionary relationships between distantly related species.  For example, rRNA studies have been used to estimate the relationships between the eukaryotic taxa (e.g. plants, animals, and fungi)<ref>http://www.mol-palaeo-lit.de/pdf/baldauf/2008/10278_Baldauf2008.pdf</ref><ref>http://rspb.royalsocietypublishing.org/content/266/1415/163.short</ref><ref>http://www.sciencemag.org/content/239/4841/748.short</ref>, and even delve into the complex relationship between the three major domains of life (bacteria, archea, eukaryota)<ref>http://www.pnas.org/content/107/29/12739.short</ref><ref>http://mmbr.asm.org/content/73/4/565.short</ref>.

Some of the most highly conserved genes (that is, genes with the least variation between species) are the genes encoding for ribosomal RNAs (rRNA).  Comparing rRNA sequences allows investigators to infer the evolutionary relationships between distantly related species.  For example, rRNA studies have been used to estimate the relationships between the eukaryotic taxa (e.g. plants, animals, and fungi)<ref>http://www.mol-palaeo-lit.de/pdf/baldauf/2008/10278_Baldauf2008.pdf</ref><ref>http://rspb.royalsocietypublishing.org/content/266/1415/163.short</ref><ref>http://www.sciencemag.org/content/239/4841/748.short</ref>, and even delve into the complex relationship between the three major domains of life (bacteria, archea, eukarya)<ref>http://www.pnas.org/content/107/29/12739.short</ref><ref>http://mmbr.asm.org/content/73/4/565.short</ref>.

Transposable DNA elements (noncoding sequences which are, almost always, nonessential) can also be used to determine the relationship between more closely-related species<ref>http://www.retrovirology.com/content/6/S2/P54/abstract</ref><ref>http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0014745</ref><ref>http://mbe.oxfordjournals.org/content/25/9/1795.short</ref>.  In fact, this technique of using transposable elements to determine phylogeny uses the same principles as the [[DNA fingerprinting]] techniques used in human paternity tests.  That separate species would share some non-coding and nonessential DNA sequences strongly implies shared ancestry.

Transposable DNA elements (noncoding sequences which are, almost always, nonessential) can also be used to determine the relationship between more closely-related species<ref>http://www.retrovirology.com/content/6/S2/P54/abstract</ref><ref>http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0014745</ref><ref>http://mbe.oxfordjournals.org/content/25/9/1795.short</ref>.  In fact, this technique of using transposable elements to determine phylogeny uses the same principles as the [[DNA fingerprinting]] techniques used in human paternity tests.  That separate species would share some non-coding and nonessential DNA sequences strongly implies shared ancestry.