Editing Convergent evolution (section)

====Na<sup>+</sup>,K<sup>+</sup>-ATPase and Insect resistance to cardiotonic steroids ====

Many examples of convergent evolution exist in insects in terms of developing resistance at a molecular level to toxins. One well-characterized example is the evolution of resistance to cardiotonic steroids (CTSs) via amino acid substitutions at well-defined positions of the α-subunit of [[Na+/K+-ATPase|Na<sup>+</sup>,K<sup>+</sup>-ATPase]] (ATPalpha). Variation in ATPalpha has been surveyed in various CTS-adapted species spanning six insect orders.<ref name="Zhen_et_al_2012">{{cite journal|last1=Zhen|first1=Ying|last2=Aardema|first2=Matthew L.|last3=Medina|first3=Edgar M.|last4=Schumer|first4=Molly|last5=Andolfatto|first5=Peter|date=2012-09-28|title=Parallel Molecular Evolution in an Herbivore Community|url= |journal=Science|language=en|volume=337|issue=6102|pages=1634–1637|doi=10.1126/science.1226630|issn=0036-8075|pmid=23019645|pmc=3770729|bibcode=2012Sci...337.1634Z}}</ref><ref>Dobler, S., Dalla, S., Wagschal, V., & Agrawal, A. A. (2012). Community-wide convergent evolution in insect adaptation to toxic cardenolides by substitutions in the Na,K-ATPase. Proceedings of the National Academy of Sciences, 109(32), 13040–13045. https://doi.org/10.1073/pnas.1202111109</ref><ref name="Yang_et_al_2019">{{cite journal |last1=Yang|first1=L|last2=Ravikanthachari|first2=N|last3=Mariño-Pérez|first3=R|last4=Deshmukh|first4=R|last5=Wu|first5=M|last6=Rosenstein|first6=A|last7=Kunte|first7=K|last8=Song|first8=H|last9=Andolfatto|first9=P.|title=Predictability in the evolution of Orthopteran cardenolide insensitivity.|journal=Philosophical Transactions of the Royal Society of London, Series B|date=2019 |volume=374 |issue=1777|pages=20180246 |doi=10.1098/rstb.2018.0246|pmid=31154978|pmc=6560278}}</ref> Among 21 CTS-adapted species, 58 (76%) of 76 amino acid substitutions at sites implicated in CTS resistance occur in parallel in at least two lineages.<ref name="Yang_et_al_2019"/> 30 of these substitutions (40%) occur at just two sites in the protein (positions 111 and 122). CTS-adapted species have also recurrently evolved [[Neofunctionalization|neo-functionalized]] duplications of ATPalpha, with convergent tissue-specific expression patterns.<ref name="Zhen_et_al_2012"/><ref name="Yang_et_al_2019"/>