Editing Leishmania (section)

==Evolution==
The details of the evolution of this genus are debated, but ''Leishmania'' apparently evolved from an ancestral trypanosome lineage. The oldest lineage is that of the [[Bodonidae]], followed by ''[[Trypanosoma brucei]]'', the latter being confined to the African continent. ''[[Trypanosoma cruzi]]'' groups with [[Trypanosoma|trypanosome]]s from bats, South American mammals, and [[kangaroo]]s suggest an origin in the Southern Hemisphere. These clades are only distantly related.

The remaining clades in this tree are ''[[Blastocrithidia]]'', ''[[Herpetomonas]]'', and ''[[Phytomonas]]''. The four genera ''[[Leptomonas]]'', ''[[Crithidia]]'', ''Leishmania'', and ''[[Endotrypanum]]'' form the terminal branches, suggesting a relatively recent origin. Several of these genera may be polyphyletic and may need further division.<ref name=Hughes2003>{{cite journal|last1 = Hughes|first1 = AL|last2 = Piontkivska|first2 = H |title = Phylogeny of Trypanosomatidae and Bodonidae (Kinetoplastida) based on 18S rRNA: evidence for paraphyly of ''Trypanosoma'' and six other genera|journal = Mol Biol Evol|volume = 20|issue = 4|pages = 644–652|doi=10.1093/molbev/msg062|pmid = 12679543|year = 2003|doi-access = free}}</ref>

The origins of genus ''Leishmania'' itself are unclear.<ref name=Momen_2000>{{cite journal |last1=Momen |first1=Hooman |last2=Cupolillo |first2=Elisa |title=Speculations on the origin and evolution of the genus Leishmania |journal=Memórias do Instituto Oswaldo Cruz |date=August 2000 |volume=95 |issue=4 |pages=583–588 |doi=10.1590/S0074-02762000000400023 | pmid = 10904419 | doi-access = free }}</ref><ref name=Noyes_2000>{{cite journal |last1=Noyes |first1=Ha |last2=Morrison |first2=Da |last3=Chance |first3=Ml |last4=Ellis |first4=Jt |title=Evidence for a neotropical origin of Leishmania |journal=Memórias do Instituto Oswaldo Cruz |date=August 2000 |volume=95 |issue=4 |pages=575–578 |doi=10.1590/S0074-02762000000400021|pmid = 10904417|doi-access = free}}</ref> One theory proposes an African origin, with migration to the Americas. Another proposes migration from the Americas to the [[Old World]] via the [[Bering Strait]] land bridge around 15 million years ago. A third theory proposes a [[Palearctic realm|Palearctic]] origin.<ref name=Kerr_2000>{{cite journal | author = Kerr SF | title = Palaearctic origin of Leishmania | journal = Mem. Inst. Oswaldo Cruz | volume = 95 | issue = 1 | pages = 75–80 | year = 2000 | pmid = 10656708 | doi = 10.1590/S0074-02762000000100011| doi-access = free }}</ref> Such migrations would entail subsequent migration of vector and reservoir or successive adaptations along the way. A more recent migration is that of ''L. infantum'' from Mediterranean countries to [[Latin America]] (known as ''L. chagasi''), since European colonization of the [[New World]], where the parasites picked up their current New World [[Vector (epidemiology)|vectors]] in their respective ecosystems.<ref>{{cite journal|last=Kuhls|first=Katrin|author2=Alam, Mohammad Zahangir |author3=Cupolillo, Elisa |author4=Ferreira, Gabriel Eduardo M. |author5=Mauricio, Isabel L. |author6=Oddone, Rolando |author7=Feliciangeli, M. Dora |author8=Wirth, Thierry |author9=Miles, Michael A. |author10=Schönian, Gabriele |author11=Kamhawi, Shaden|title=Comparative Microsatellite Typing of New World Leishmania infantum Reveals Low Heterogeneity among Populations and Its Recent Old World Origin|journal=PLOS Neglected Tropical Diseases|date=7 June 2011|volume=5|issue=6|pages=e1155|doi=10.1371/journal.pntd.0001155|pmid=21666787|pmc=3110170 |doi-access=free }}</ref>  This is the cause of the epidemics now evident. One recent New World epidemic concerns foxhounds in the USA.<ref>{{Cite journal | last1 = Duprey | first1 = Z. H. | last2 = Steurer | first2 = F. J. | last3 = Rooney | first3 = J. A. | last4 = Kirchhoff | first4 = L. V. | last5 = Jackson | first5 = J. E. | last6 = Rowton | first6 = E. D. | last7 = Schantz | first7 = P. M. | doi = 10.3201/eid1203.050811 | title = Canine Visceral Leishmaniasis, United States and Canada, 2000–2003 | journal = Emerging Infectious Diseases | volume = 12 | issue = 3 | pages = 440–446 | year = 2006 | pmid =  16704782| pmc =3291440 }}</ref>

Although it was suggested that ''Leishmania'' might have evolved in the [[Neotropics]],<ref name=Noyes1997>{{cite journal|last1 = Noyes|first1 = HA|last2 = Arana|first2 = BA| last3 = Chance|first3 = ML|last4 = Maingon|first4 = R|year = 1997|title = The ''Leishmania hertigi'' (Kinetoplastida; Trypanosomatidae) complex and the lizard ''Leishmania'': their classification and evidence for a neotropical origin of the ''Leishmania''-''Endotrypanum'' clade |journal = J Eukaryot Microbiol|volume = 44|issue = 5|pages = 511–557|doi=10.1111/j.1550-7408.1997.tb05732.x|pmid = 9304821|s2cid = 27460253}}</ref> this is probably true for species belonging to the subgenera ''Viannia'' and ''Endotrypanum''. However, there is evidence that the primary evolution of the subgenera ''Leishmania'' and ''Sauroleishmania'' is the Old World. While the ''Mundinia'' species appear to be more universal in their evolution. One theory is that different lineages became isolated geographically during different periods and it is this that gave rise to this evolutionary mosaicism. But there is no doubt that the Leishmaniinae are a monophyletic group.

A large data set analysis suggests that ''Leishmania'' evolved 90 to 100 million years ago in [[Gondwana]].<ref name=Harkins2015>{{cite journal |doi=10.1016/j.meegid.2015.11.030 |pmid=26708057 |title=Phylogenomic reconstruction supports supercontinent origins for Leishmania |journal=Infection, Genetics and Evolution |volume=38 |pages=101–9 |year=2016 |last1=Harkins |first1=Kelly M |last2=Schwartz |first2=Rachel S |last3=Cartwright |first3=Reed A |last4=Stone |first4=Anne C |doi-access=free }}</ref> The reptile infecting species originated in mammalian clades.

''Sauroleishmania'' species were originally defined on the basis that they infected [[reptile]]s ([[lizard]]s) rather than [[mammal]]s. Based on molecular evidences, they have been moved to subgenus status within ''Leishmania''. This subgenus probably evolved from a group that originally infected mammals.<ref name=Croan1997>{{cite journal |doi=10.1016/S0166-6851(97)00111-4 |pmid=9364962 |title=Evolution of the genus Leishmania revealed by comparison of DNA and RNA polymerase gene sequences |journal=Molecular and Biochemical Parasitology |volume=89 |issue=2 |pages=149–59 |year=1997 |last1=Croan |first1=David G |last2=Morrison |first2=David A |last3=Ellis |first3=John T }}</ref>