Editing Plasmodium (section)

==Evolution and taxonomy==
[[File:Culex malariager in Dominican amber.jpg|thumb|Oldest mosquito fossil with ''[[Plasmodium dominicana]]'', 15–20 million years old]]

=== Taxonomy ===
''Plasmodium'' belongs to the [[phylum]] [[Apicomplexa]], a taxonomic group of single-celled parasites with characteristic [[Apicomplexa#General features|secretory organelles]] at one end of the cell.<ref name=Morrison2009>{{cite journal |doi=10.1016/j.pt.2009.05.010 |pmid=19635681 |title=Evolution of the Apicomplexa: Where are we now? |journal=Trends in Parasitology |volume=25 |issue=8 |pages=375–82 |year=2009 |last1=Morrison |first1=David A.}}</ref> Within Apicomplexa, ''Plasmodium'' is within the [[Order (biology)|order]] [[Haemosporida]], a group that includes all apicomplexans that live within blood cells.<ref>{{cite web|url=http://tolweb.org/Haemosporina/124976 |access-date=1 May 2018 |title=Haemospororida Danielewski 1885 |author=Votypka J |website=Tree of Life}}</ref> Based on the presence of the pigment [[hemozoin]] and the method of [[Merogony|asexual reproduction]], the order is further split into four families, of which ''Plasmodium'' is in the [[Family (biology)|family]] [[Plasmodiidae]].<ref name=Perkins2014/>

The genus ''Plasmodium'' consists of over 200 species, generally described on the basis of their appearance in blood smears of infected vertebrates.<ref name=Martinsen2013>{{cite book |title=Malaria Parasites: Comparative Genomics, Evolution and Molecular Biology |editor1=Carlton, J.M. |editor2=Perkins, S.L. |editor3=Deitsch, K.W.  |isbn=978-1908230072 |publisher=Caister Academic Press |date=2013 |chapter=The Diversity of ''Plasmodium'' and other Haemosporidians: The Intersection of Taxonomy, Phylogenetics, and Genomics |author1=Martinsen, E. S. |author2=Perkins, S. L. |pages=1–15}}</ref> These species have been categorized on the basis of their morphology and host range into 14 subgenera:<ref name=Perkins2014>{{cite journal|title=Malaria's Many Mates: Past, Present, and Future of the Systematics of the Order Haemosporida |author=Perkins, S. L. |date=2014 |journal=Journal of Parasitology |volume=100 |issue=1 |pages=11–25 |doi=10.1645/13-362.1|pmid=24059436 |s2cid=21291855 }}</ref>

* Subgenus ''[[Asiamoeba]]'' <small>(Telford, 1988)</small> – reptiles
* Subgenus ''[[Bennettinia]]'' <small>(Valkiunas, 1997)</small> – birds
* Subgenus ''[[Carinamoeba]]'' <small>(Garnham, 1966)</small> – reptiles
* Subgenus ''[[Giovannolaia]]'' <small>(Corradetti, et al. 1963)</small> – birds
* Subgenus ''[[Haemamoeba]]'' <small>(Corradetti, et al. 1963)</small> – birds
* Subgenus ''[[Huffia]]'' <small>(Corradetti, et al. 1963)</small> – birds
* Subgenus ''[[Lacertamoeba]]'' <small>(Telford, 1988)</small> – reptiles
* Subgenus ''[[Laverania]]'' <small>(Bray, 1958)</small> – great apes, humans 
* Subgenus ''[[Novyella]]'' <small>(Corradetti, et al. 1963)</small> – birds
* Subgenus ''[[Ophidiella]]'' <small>(Telford, 1988)</small> – reptiles
* Subgenus ''[[Paraplasmodium]]'' <small>(Telford, 1988)</small> – reptiles
* Subgenus ''Plasmodium'' <small>(Bray, 1955)</small> – monkeys and apes
* Subgenus ''[[Sauramoeba]]'' <small>(Garnham, 1966)</small> – reptiles
* Subgenus ''[[Vinckeia]]'' <small>(Garnham, 1964)</small> – mammals inc. primates

Species infecting [[monkey]]s and [[apes]] with the exceptions of ''P. falciparum'' and ''P. reichenowi'' (which together make up the subgenus ''Laverania'') are classified in the subgenus ''Plasmodium''. Parasites infecting other [[mammal]]s including some primates ([[lemur]]s and others) are classified in the subgenus ''Vinckeia''. The five subgenera ''Bennettinia'', ''Giovannolaia'', ''Haemamoeba'', ''Huffia'', and ''Novyella'' contain the known avian malarial species.<ref name=Valkiunas4>{{cite book |title=Avian Malaria Parasites and Other Haemosporidia |author=Valkiunas, Gediminas  |publisher=CRC Press |isbn=9780415300971 |date=2004 |chapter=Brief Historical Summary |pages=9–15}}</ref> The remaining subgenera: ''Asiamoeba'', ''Carinamoeba'', ''Lacertamoeba'', ''Ophidiella'', ''Paraplasmodium'', and ''Sauramoeba'' contain the diverse groups of parasites found to infect reptiles.<ref name="Telford1988"/>

===Phylogeny===

More recent studies of ''Plasmodium'' species using molecular methods have implied that the group's evolution has not perfectly followed taxonomy.<ref name=TOL>{{cite web |url=http://tolweb.org/Plasmodium/68071 |access-date=1 June 2016 |title=''Plasmodium'' |publisher=Tree of Life Web Project |author1=Zilversmit, M. |author2=Perkins, S.}}</ref> Many ''Plasmodium'' species that are morphologically similar or infect the same hosts turn out to be only distantly related.<ref name=Rich2003>{{cite book |doi=10.1016/S0065-308X(03)54005-2 |pmid=14711087 |title=Progress in Malaria Research: the Case for Phylogenetics |volume=54 |pages=255–80 |year=2003 |last1=Rich |first1=S. |last2=Ayala |first2=F |series=Advances in Parasitology |isbn=978-0-12-031754-7}}</ref> In the 1990s, several studies sought to evaluate evolutionary relationships of ''Plasmodium'' species by comparing [[ribosomal RNA]] and a surface protein gene from various species, finding the human parasite ''P. falciparum'' to be more closely related to avian parasites than to other parasites of primates.<ref name=Perkins2014/> However, later studies sampling more ''Plasmodium'' species found the parasites of mammals to form a clade along with the genus ''[[Hepatocystis]]'', while the parasites of birds or lizards appear to form a separate clade with evolutionary relationships not following the subgenera:<ref name=Perkins2014/><ref>{{cite journal|doi=10.1016/j.ympev.2007.11.012 |pmid=18248741 |title=A three-genome phylogeny of malaria parasites (''Plasmodium'' and closely related genera): Evolution of life-history traits and host switches |vauthors=Martinsen ES, Perkins SL, Schall JJ |journal=Molecular Phylogenetics and Evolution |volume=47 |issue=1 |date=April 2008 |pages=261–273}}</ref>

{{clade| style=font-size:85%;line-height:85%
|1=''[[Leucocytozoon]]'' 
|2={{clade
    |1=''[[Haemoproteus]]''
    |label2=''Plasmodium''
    |2= {{clade
        |1=''Plasmodium'' of lizards and birds
        |2= {{clade
            |1=Subgenus ''Laverania''
            |2={{clade
                |1=Subgenus ''Plasmodium''
                |2=Subgenus ''Vinckeia''
                |3=''[[Hepatocystis]]'' (parasites of bats)
                }}
            }}
        }}
    }} 
}}

Estimates for when different ''Plasmodium'' lineages diverged have differed broadly. Estimates for the diversification of the order Haemosporida range from around 16.2 million to 100 million years ago.<ref name=Perkins2014/> There has been particular interest in dating the divergence of the human parasite ''P. falciparum'' from other ''Plasmodium'' lineages due to its medical importance. For this, estimated dates range from 110,000 to 2.5 million years ago.<ref name=Perkins2014/>