Editing Passenger pigeon (section)

===Evolution===
[[File:Ectopistes migratorius (passenger pigeon).jpg|thumb|Mounted male passenger pigeon, [[Field Museum of Natural History]]]]
[[File:Patagioenas fasciata -San Luis Obispo, California, USA-8 (1).jpg|thumb|[[Band-tailed pigeon]], a species in the related genus ''[[Patagioenas ]]'']]
[[File:Zenaida macroura -California-8-2c.jpg|thumb|The physically similar [[mourning dove]] is not closely related.]]
The passenger pigeon was a member of the pigeon and dove family, [[Columbidae]]. The oldest known fossil of the genus is an isolated humerus (USNM 430960) known from the Lee Creek Mine in North Carolina in sediments belonging to the [[Yorktown Formation]], dating to the [[Zanclean]] stage of the [[Pliocene]], between 5.3 and 3.6 million years ago.<ref>{{cite journal |last1=Ray |first1=Clayton E. |last2=Bohaska |first2=David J. |title=Miocene and Pliocene birds from the Lee Creek Mine, North Carolina in Geology and Paleontology of the Lee Creek Mine, North Carolina, III |date=2001 |journal=Smithsonian Contributions to Paleobiology |volume=90 |language=en |issue=90 |pages=299–300 |doi=10.5479/si.00810266.90.1 |hdl=10088/2006 |url=https://repository.si.edu/handle/10088/2006}}</ref> Its closest living relatives were long thought to be the [[Zenaida doves|''Zenaida'' doves]], based on morphological grounds, particularly the physically similar mourning dove (now ''Z.&nbsp;macroura'').<ref name="Blockstein 4"/><ref>{{cite conference |last=Miller |first=W. J. |title=The Biology and Natural History of the Mourning Dove |book-title=Should Doves be Hunted in Iowa? |publisher=Ames [[Audubon Society]] |date=January 16, 1969 |location=Ames, IA |url=http://www.ringneckdove.com/Wilmer's%20WebPage/mourning__doves.htm |access-date=April 23, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120920051011/http://www.ringneckdove.com/Wilmer%27s%20WebPage/mourning__doves.htm |archive-date=September 20, 2012}}</ref> It was even suggested that the mourning dove belonged to the genus ''Ectopistes'' and was listed as ''E.&nbsp;carolinensis'' by some authors, including [[Thomas Mayo Brewer]].<ref name="Brewer 717">{{cite book |last=Brewer |first=T. M. |author-link=Thomas Mayo Brewer |title=Wilson's American Ornithology: with Notes by Jardine; to which is Added a Synopsis of American Birds, Including those Described by Bonaparte, Audubon, Nuttall, and Richardson |publisher=Otis, Broaders, and Company |year=1840 |location=Boston |page=[https://archive.org/details/wilsonsamericano00wils/page/717 717] |url=https://archive.org/details/wilsonsamericano00wils}}</ref> The passenger pigeon was supposedly descended from ''Zenaida'' pigeons that had adapted to the woodlands on the plains of central North America.<ref name="Extinct Birds"/>

The passenger pigeon differed from the species in the genus ''Zenaida'' in being larger, lacking a facial stripe, being [[sexually dimorphic]], and having [[iridescent]] neck feathers and a smaller [[clutch (eggs)|clutch]]. In a 2002 study by American geneticist [[Beth Shapiro]] et al., museum specimens of the passenger pigeon were included in an [[ancient DNA]] analysis for the first time (in a paper focusing mainly on the [[dodo]]), and it was found to be the [[sister taxon]] of the cuckoo-dove genus ''[[Macropygia]]''. The ''Zenaida'' doves were instead shown to be related to the quail-doves of the genus ''[[Geotrygon]]'' and the ''[[Leptotila]]'' doves.<ref>{{cite journal |last1=Shapiro |first1=B. |last2=Sibthorpe |first2=D. |last3=Rambaut |first3=A. |last4=Austin |first4=J. |last5=Wragg |first5=G. M. |last6=Bininda-Emonds |first6=O. R. P. |last7=Lee |first7=P. L. M. |last8=Cooper |first8=A. |year=2002 |title=Flight of the Dodo |journal=Science |volume=295 |issue=5560 |page=1683 |doi=10.1126/science.295.5560.1683 |pmid=11872833 |ref={{sfnRef |Shapiro et al. |2002 |pmid=11872833 |doi=10.1126/science.295.5560.1683 |url=https://pgl.soe.ucsc.edu/dodo_Shapiro02.pdf}}}}</ref><ref name="Fulton"/><ref name=Johnson/>

A more extensive 2010 study instead showed that the passenger pigeon was most closely related to the New World ''[[Patagioenas]]'' pigeons, including the [[band-tailed pigeon]] (''P.&nbsp;fasciata'') of western North America, which are related to the Southeast Asian species in the genera ''[[Turacoena]]'', ''Macropygia'', and ''[[Reinwardtoena]]''. This [[clade]] is also related to the ''Columba'' and ''[[Streptopelia]]'' doves of the Old World (collectively termed the "typical pigeons and doves"). The authors of the study suggested that the ancestors of the passenger pigeon may have colonized the New World from South East Asia by flying across the [[Pacific Ocean]], or perhaps across [[Beringia]] in the north.<ref name=Johnson>{{cite journal |last=Johnson |first=K. P. |author2=Clayton, D. H. |author3=Dumbacher, J. P. |author4=Fleischer, R. C. |title=The flight of the Passenger Pigeon: phylogenetics and biogeographic history of an extinct species |journal=Molecular Phylogenetics and Evolution |volume=57 |issue=1 |pages=455–8 |year=2010 |bibcode=2010MolPE..57..455J |pmid=20478386 |doi=10.1016/j.ympev.2010.05.010}}</ref>

In a 2012 study, the [[nuclear DNA]] of the passenger pigeon was analyzed for the first time, and its relationship with the ''Patagioenas'' pigeon was confirmed. In contrast to the 2010 study, these authors suggested that their results could indicate that the ancestors of the passenger pigeon and its Old World relatives may have originated in the [[Neotropical region]] of the New World.<ref name="Fulton">{{cite journal |last=Fulton |first=T. L. |author2=Wagner, S. M. |author3=Fisher, C. |author4=Shapiro, B. |title=Nuclear DNA from the Extinct Passenger Pigeon (''Ectopistes migratorius'') Confirms a Single Origin of New World Pigeons |journal=[[Annals of Anatomy]] |volume=194 |issue=1 |pages=52–7 |year=2012 |bibcode=2012AnAAA.194...52F |pmid=21482085 |doi=10.1016/j.aanat.2011.02.017}}</ref>

The [[cladogram]] below follows the 2012 DNA study showing the position of the passenger pigeon among its closest relatives:<ref name="Fulton"/>
{{clade |style=font-size:100%; line-height:100%
|1={{clade
 |1={{clade
  |1={{clade
   |1={{clade
    |1={{clade
     |1=''[[Macropygia]]'' (cuckoo-doves)
     |2=''[[Reinwardtoena]]''}}
   |2=''[[Turacoena]]''}}
  |2={{clade
   |1=''[[Columba (genus)|Columba]]'' (Old World pigeons)
   |2=''[[Streptopelia]]'' (turtle doves and collared doves)}}}}
 |2={{clade
  |1=''[[Patagioenas]]'' (New World pigeons)
  |2='''''Ectopistes''''' ('''passenger pigeon''')}}}}}}}}

DNA in old museum specimens is often degraded and fragmentary, and passenger pigeon specimens have been used in various studies to discover improved methods of analyzing and assembling genomes from such material. DNA samples are often taken from the toe pads of bird skins in museums, as this can be done without causing significant damage to valuable specimens.<ref>{{cite book |chapter=Case Study: Recovery of Ancient Nuclear DNA from Toe Pads of the Extinct Passenger Pigeon |title=Ancient DNA |volume=840 |pages=29–35 |series=Methods in Molecular Biology |year=2012 |last1=Fulton |first1=T. L. |last2=Wagner |first2=S. M. |last3=Shapiro |first3=B. |isbn=978-1-61779-515-2 |pmid=22237518 |doi=10.1007/978-1-61779-516-9_4}}</ref><ref>{{cite journal |title=The De Novo Assembly of Mitochondrial Genomes of the Extinct Passenger Pigeon (''Ectopistes migratorius'') with Next Generation Sequencing |journal=[[PLOS One]] |volume=8 |issue=2 |pages=e56301 |year=2013 |last1=Hung |first1=C. M. |last2=Lin |first2=R. C. |last3=Chu |first3=J. H. |last4=Yeh |first4=C. F. |last5=Yao |first5=C. J. |last6=Li |first6=S. H. |bibcode=2013PLoSO...856301H |pmid=23437111 |doi=10.1371/journal.pone.0056301 |doi-access=free |pmc=3577829}}</ref> The passenger pigeon had no known subspecies.<ref name="Blockstein 4">{{Harvnb|Blockstein|2002|p=4}}</ref> [[Hybrid (biology)|Hybridization]] occurred between the passenger pigeon and the [[Barbary dove]] (''Streptopelia risoria'') in the aviary of [[Charles Otis Whitman]] (who owned many of the last captive birds around the turn of the 20th century, and kept them with other pigeon species) but the offspring were infertile.<ref name="Extinct Birds">{{cite book |last1=Hume |first1=J. P. |author-link=Julian Pender Hume |last2=Walters |first2=M. |title=Extinct Birds |publisher=T & AD Poyser |year=2012 |location=London |isbn=978-1-4081-5725-1 |pages=144{{ndash}}146}}</ref><ref>{{cite journal |jstor=4070695 |last=Deane |first=R. |title=The Passenger Pigeon (Ectopistes migratorius) in Confinement |journal=The Auk |volume=25 |issue=2 |pages=181–183 |year=1908 |doi=10.2307/4070695 |url=https://archive.org/stream/jstor-4070695/4070695#page/n1/mode/2up}}</ref>