Editing Quagga (section)

===Evolution===

The quagga is poorly represented in the fossil record, and the identification of these fossils is uncertain, as they were collected at a time when the name "quagga" referred to all zebras.<ref name="skinner" /> Fossil skulls of ''[[Equus mauritanicus]]'' from Algeria have been claimed to show affinities with the quagga and the plains zebra, but they may be too badly damaged to allow definite conclusions to be drawn from them.<ref name="Azzaroli">{{Cite journal |last1=Azzaroli |first1=A. |last2=Stanyon |first2=R. |doi=10.1007/BF03001000 |title=Specific identity and taxonomic position of the extinct Quagga |journal=Rendiconti Lincei |volume=2 |issue=4 |pages=425 |year=1991 |s2cid=87344101 }}</ref>

{{multiple image
| align = right
| perrow=2/2
| total_width = 350
| header = 
| image1 = Berlin Quagga.jpg
| alt1 =
| image2 = Bamberg Naturkundemuseum Quagga 17RM1912.jpg
| alt2=
| image3 = Equus quagga quagga12.JPG
| image4 = Quagga Naturhistorisches Museum Basel 27102013 3.jpg
|footer = [[Taxidermy]] specimens in Naturkunde-Museum, Bamberg, [[Natural History Museum, Berlin]], [[Museo Civico di Storia Naturale di Milano]], and [[Naturhistorisches Museum, Basel]] (the two above have been sampled for [[DNA]])
}}

The quagga was the first extinct animal to have its [[DNA]] analysed,<ref name="1984 quagga">{{Cite journal |doi=10.1038/312282a0 |last1=Higuchi |first1=R. |last2=Bowman |first2=B. |last3=Freiberger |first3=M. |last4=Ryder |first4=O. A. |last5=Wilson |first5=A. C. |title=DNA sequences from the quagga, an extinct member of the horse family |journal=Nature |volume=312 |issue=5991 |pages=282–284 |year=1984 |pmid=6504142 |bibcode=1984Natur.312..282H |s2cid=4313241 }}</ref> and this 1984 study launched the field of [[ancient DNA]] analysis. It confirmed that the quagga was more closely related to zebras than to horses,<ref name="smithsonian"/> with the quagga and [[mountain zebra]] (''Equus zebra'') sharing an ancestor 3–4&nbsp;million years ago.<ref name="1984 quagga"/> An [[immunological]] study published the following year found the quagga to be closest to the plains zebra.<ref>{{Cite journal |last1=Lowenstein |first1=J. M. |last2=Ryder |first2=O. A. |doi=10.1007/BF01951724 |title=Immunological systematics of the extinct quagga (Equidae) |journal=Experientia |volume=41 |issue=9 |pages=1192–1193 |year=1985 |pmid=4043335 |s2cid=27281662 }}</ref> A 1987 study suggested that the [[mtDNA]] of the quagga diverged at a range of roughly 2&nbsp;percent per&nbsp;million years, similar to other mammal species, and again confirmed the close relation to the plains zebra.<ref>{{Cite journal |last1=Higuchi |first1=R. G. |last2=Wrischnik |first2=L. A. |last3=Oakes |first3=E. |last4=George |first4=M. |last5=Tong |first5=B. |last6=Wilson |first6=A. C. |doi=10.1007/BF02603111 |title=Mitochondrial DNA of the extinct quagga: Relatedness and extent of postmortem change |journal=Journal of Molecular Evolution |volume=25 |issue=4 |pages=283–287 |year=1987 |pmid=2822938 |bibcode=1987JMolE..25..283H|s2cid=28973189 }}</ref>

Later morphological studies came to different conclusions. A 1999 analysis of cranial measurements found that the quagga was as different from the plains zebra as the latter is from the mountain zebra.<ref name="smithsonian"/> A 2004 study of skins and skulls instead suggested that the quagga was not a distinct species, but a subspecies of the plains zebra.<ref name="Hippotigris">{{Cite journal |last1=Groves |first1=C. P. |last2=Bell |first2=C. H. |doi=10.1078/1616-5047-00133 |title=New investigations on the taxonomy of the zebras genus ''Equus'', subgenus ''Hippotigris'' |journal=Mammalian Biology - Zeitschrift für Säugetierkunde |volume=69 |issue=3 |pages=182 |year=2004 |bibcode=2004MamBi..69..182G }}</ref> In spite of these findings, many authors subsequently kept the plains zebra and the quagga as separate species.<ref name=skinner/>

A [[genetic study]] published in 2005 confirmed the subspecific status of the quagga. It showed that the quagga had little genetic diversity, and that it diverged from the other plains zebra subspecies only between 120,000 and 290,000 years ago, during the [[Pleistocene]], and possibly the penultimate glacial maximum. Its distinct coat pattern perhaps evolved rapidly because of geographical isolation and/or adaptation to a drier environment. In addition, plains zebra subspecies tend to have less striping the further south they live, and the quagga was the most southern-living of them all. Other large African [[ungulate]]s diverged into separate species and subspecies during this period, as well, probably because of the same climate shift.<ref name="smithsonian">{{Cite journal |last1=Hofreiter |first1=M. |last2=Caccone |first2=A. |last3=Fleischer |first3=R. C. |last4=Glaberman |first4=S. |last5=Rohland |first5=N. |last6=Leonard |first6=J. A. |doi=10.1098/rsbl.2005.0323 |title=A rapid loss of stripes: The evolutionary history of the extinct quagga |journal=Biology Letters |volume=1 |issue=3 |pages=291–295 |year=2005 |pmid=17148190 |pmc=1617154}}</ref>

The simplified [[cladogram]] below is based on the 2005 analysis (some taxa shared [[haplotype]]s and could, therefore, not be differentiated):<ref name="smithsonian"/>
{{clade| style=font-size:100%; line-height:100%
|1={{clade
 |1=[[Mountain zebra]] (''E. zebra'')
 |2={{clade
  |1=[[Grévy's zebra]] (''E. grevyi'')
  |2={{clade
    |1={{clade
     |1='''Quagga''' ('''''E. q. quagga''''')
     |2=[[Damara zebra]] (''E. q. antiquorum'')-[[Chapman's zebra]] (''E. q. chapmani'')}}
    |2=[[Grant's zebra]] (''E. q. boehmi'') }}
  }}
 }}
}}

A 2018 genetic study of plains zebras populations confirmed the quagga as a member of that species. They found no evidence for subspecific differentiation based on morphological differences between southern populations of zebras, including the quagga. Modern plains zebra populations may have originated from southern Africa, and the quagga appears to be less divergent from neighbouring populations than the northernmost living population in northeastern [[Uganda]]. Instead, the study supported a north–south genetic continuum for plains zebras, with the Ugandan population being the most distinct. Zebras from [[Namibia]] appear to be the closest genetically to the quagga.<ref name="PedersenAlbrechtsen2018">{{Cite journal |last1=Pedersen |first1=Casper-Emil T. |last2=Albrechtsen |first2=Anders |last3=Etter |first3=Paul D. |last4=Johnson |first4=Eric A. |last5=Orlando |first5=Ludovic |last6=Chikhi |first6=Lounes |last7=Siegismund |first7=Hans R. |last8=Heller |first8=Rasmus |title=A southern African origin and cryptic structure in the highly mobile plains zebra |journal=Nature Ecology & Evolution |volume=2 |issue=3 |pages=491–498 |issn=2397-334X |doi=10.1038/s41559-017-0453-7 |pmid=29358610 |date=22 January 2018 |bibcode=2018NatEE...2..491P |s2cid=3333849 }}</ref>