Grizzly-polar bear hybrid

An bayar da rahoton yiwuwar hybrids na beyar da aka haifa a cikin daji kuma an harbe su a baya, amma ba a sami gwaje-gwajen DNA don tabbatar da asalin beyar ba.

Binciken kwayar halitta ya bayyana lokuta da yawa na haɗuwa tsakanin nau'in beyar,    ciki har da introgression na Beyar polar zuwa beyar launin ruwan kasa a lokacin Pleistocene ("grizzly bear" shine sunan gama gari na Ursus arctos yayin da ake amfani da "beyar launin ruwan hoda" a duniya da kimiyya don komawa ga jinsin gaba ɗaya). 

 Abubuwan da suka faru a cikin daji 
Tare da yawan abubuwan da ake zargi da kuma tabbatar da shari'o'i takwas,  ra'ayoyin yadda irin wannan haɗe-haɗe na iya 'Yar'uwa a dabi'a sun zama fiye da zato. Kodayake waɗannan nau'ikan 'yan uwa sau da yawa suna zaune a yankuna masu kusa, hulɗa kai tsaye ba al'ada ba ne saboda bears na polar farauta, haifuwa, kuma wani lokacin ma suna yin haihuwa a kan kankara na teku, inda bears masu launin ruwan kasa suna da salon rayuwa na duniya.

Masana kimiyya ba su iya ba da cikakken bayani game da lamarin ba. Ɗaya daga cikin ka'idojin ya nuna cewa yayin da yawan jama'a ke ƙaruwa, bears maza suna barin kogon su da wuri yayin da mata ke zaune tare da 'ya'yansu. Wannan yana nufin cewa ga maza grizzlies, mata polar bears sun zama ma'aurata masu iya aiki. Wannan shine babban dalilin da aka yi hasashen cewa an ruwaito cewa hybrids suna da iyaye masu launin toka da iyaye mata masu launin toka. Masana kimiyya sun kuma yi zaton wannan na iya zama batun canjin yanayi. Yayin da hunturu ya fara raguwa, grizzlies sun fara motsawa akai-akai suna fadada yankinsu. Wannan fadada yankin ya kuma canza abin da waɗannan grizzlies ke ci. Tare da rashin 'ya'yan itace, salmon, da tsire-tsire na halitta a cikin Arctic, an ga grizzlies farauta, wanda shine ganima na yau da kullun ga bears. Wannan kusanci na kusa yayin farauta wani bayani ne da aka gabatar don haɗuwa.

 Binciken da aka yi a shekara ta 2006 
Jim Martell, wani mafarauci daga Idaho, an bayar   ya harbe wani grizzly-polar bear hybrid kusa da Sachs Harbor a kan Banks Island, Northwest Territories a ranar  Afrilu, 2006. Jami'ai sun dauki sha'awar wannan halitta bayan sun lura cewa yayin da yake da kauri, farar fata mai kauri mai kama da nau'in bears, yana kuma da dogayen farauta, da baya, fuska mara zurfi, da faci mai launin ruwan kasa a idanunta, hancinta, baya, da kafa, wadanda dukkansu halaye ne na berayen grizzly . Idan da an yanke hukuncin cewa mafarauci ya kasance mai kauri, da mafarauci zai fuskanci yuwuwar tarar dalar Amurka 1,000 kuma har zuwa shekara guda a gidan yari. 

Gwajin DNA da aka gudanar ta Wildlife Genetics International a British Columbia ta tabbatar da cewa wani nau'i ne, tare da mahaifiyar beyar polar da mahaifin beyar grizzly. Wannan shi ne shari'ar farko da aka rubuta a cikin daji,  kodayake an san cewa wannan mahaukaci yana yiwuwa ta hanyar halitta kuma an haifi wasu mahaukaci a cikin gidajen namun daji a baya. 

A ranar 8 ga Mayu, 2006, binciken gilashin grizzly-polar bear ya sami karin kulawa lokacin da, ba da daɗewa ba bayan an sanar da labarin, shirin talabijin na wasan kwaikwayo The Colbert Report da zuciya ɗaya ya kira sabon nau'in a matsayin barazanar farko ga Tsaron Amurka.

A cikin jayayya da yawa, an mayar da beyar zuwa Martell.

 Abubuwan da aka gano na gaba 
alt=A taxidermied brown and white bear|thumb|Beyar Ulukhaktok
A ranar 8 ga Afrilu, 2010, David Kuptana, mafaraucin Inuvialuk daga al'ummar Ulukhaktok da ke tsibirin Victoria Island ya harbe abin da ya yi zaton beyar polar ce. Bayan an duba beyar da aka gwada DNA ɗinsa, an gano cewa mahaifiyar beyar ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ce kuma uban beyar beyar ce. Beyar tana da sifofin jiki tsaka-tsaki tsakanin grizzlies da polar bears, kamar su Jawo mai launin ruwan kasa akan tafukan sa, dogayen farauta, da kai mai kamshi. 

Hanyoyin kwayar halitta da aka yi amfani da su don tabbatar da dangantakar iyali da kakannin bears na arewacin Kanada sun samo asali ne daga farkon shekarun 1990, kuma ba su da isasshen ƙarfi don bayyana tarihin dā. Koyaya, sabbin hanyoyin genomics suna nazarin dubban shafuka a cikin kwayar halitta, suna ba da damar gano tarihin ɓangarorin chromosomes zuwa wasu al'ummomi (ko jinsuna idan aka kwatanta da hybridization). Nazarin genomic na bears masu launin ruwan kasa da bears masu zafi sun nuna cewa kwayar halitta tana gudana daga bears masu sanyi zuwa bears masu launi, amma ba haka ba, ya yadu a lokaci da sarari a lokacin Pleistocene. Musamman bayanin kula, bears da ke zaune a Tsibirin Alexander Archipelago na kudu maso gabashin Alaska suna bin diddigin DNA na mitochondrial da mahaifiyarsu ta gada gaba ɗaya ga bears na polar, amma sama da 90% na kwayar nukiliyar su ga bears masu launin ruwan kasa. Wannan ya bayyana don nuna wani tsari wanda aka bar yawan bears a baya yayin da jinsunan suka koma arewa a ƙarshen zamanin kankara na ƙarshe, tare da bears masu launin ruwan kasa na maza daga baya suna gabatar da kwayoyin halitta daga yankin da ke kusa, amma bears masu ruwan kasa na mata gabaɗaya ba su iya ko ba su so su yi iyo a fadin kilomita da yawa na teku don isa tsibiran (saboda haka rashin musayar DNA na mitochondrial). 

 Beyar Arviat 
An bayar da rahoton cewa wani beyar da aka harbe a cikin 2016, kusa da Arviat a yammacin gabar Hudson Bay, wani nau'i ne, tare da hukumomin labarai da ke bayyana cewa wannan sakamakon Canjin yanayi ne. Wannan beyar tana da haske a launi, amma 'blonde' bears sun zama ruwan dare a kan Barren Grounds, kuma beyar Arviat ba ta da wasu siffofi na halayen hybrids. An tabbatar da beyar Arviat ta hanyar nazarin kwayar halitta don zama beyar launin ruwan kasa mai tsabta.

 Yaduwar yaduwar bears masu launin ruwan kasa a matsayin mai yiwuwa mai ba da gudummawa 
A halin yanzu ba a san dalilin da ya sa ake samun grizzly bears a cikin mazaunin polar bears ba. Kodayake an kashe wani grizzly bear a Tsibirin Banks a cikin 1951, ya kasance, har zuwa kwanan nan, ya kasance mai wuya ga wannan nau'in ya ɓace da nisa a arewacin bakin tekun Kanada. A cikin 1991, an rubuta takardun farauta guda ɗaya ko fiye da grizzly bears a kan kankara a kusa da Tsibirin Melville, sama da kilomita 500 daga bakin tekun. A cikin 2003 da 2004, ƙungiyar ilimin ƙasa da ke aiki a tsibirin Melville sun sami shaidar hoto da DNA na beyar grizzly a yankin. Rahoton su kuma ya tattara bayanai game da wasu abubuwan da suka faru a cikin Tsibirin Arctic na Kanada. 

Grizzly bears a bayyane suke fadada iyakarsu gabas a fadin Barren Grounds zuwa Hudson Bay, da kudu zuwa arewacin Saskatchewan da Manitoba. Tsakanin shekara ta 2003 zuwa shekara ta 2008, an gano mutane bakwai a cikin Wapusk National Park a kudancin Churchill, Manitoba, wani yanki da bears ke amfani da shi don haihuwa da kuma mafaka a lokacin lokacin lokacin da ba a kankara ba a Hudson Bay.

 Haɗuwa ta dā 
Hanyoyin kwayar halitta da aka yi amfani da su don tabbatar da dangantakar iyali da kakannin bears na arewacin Kanada sun samo asali ne daga farkon shekarun 1990, kuma ba su da isasshen ƙarfi don bayyana tarihin dā. Koyaya, sabbin hanyoyin genomics suna nazarin dubban shafuka a cikin kwayar halitta, suna ba da damar gano tarihin ɓangarorin chromosomes zuwa wasu al'ummomi (ko jinsuna idan aka kwatanta da hybridization). Nazarin genomic na bears masu launin ruwan kasa da bears masu zafi sun nuna cewa kwayar halitta tana gudana daga bears masu sanyi zuwa bears masu launi, amma ba haka ba, ya yadu a lokaci da sarari a lokacin Pleistocene. Musamman bayanin kula, bears da ke zaune a Tsibirin Alexander Archipelago na kudu maso gabashin Alaska suna bin diddigin DNA na mitochondrial da mahaifiyarsu ta gada gaba ɗaya ga bears na polar, amma sama da 90% na kwayar nukiliyar su ga bears masu launin ruwan kasa. Wannan ya bayyana don nuna wani tsari wanda aka bar yawan bears a baya yayin da jinsunan suka koma arewa a ƙarshen zamanin kankara na ƙarshe, tare da bears masu launin ruwan kasa na maza daga baya suna gabatar da kwayoyin halitta daga yankin da ke kusa, amma bears masu ruwan kasa na mata gabaɗaya ba su iya ko ba su so su yi iyo a fadin kilomita da yawa na teku don isa tsibiran (saboda haka rashin musayar DNA na mitochondrial). 

Irin waɗannan binciken ba a iyakance su ga bears da bears masu launin ruwan kasa ba, kuma yanzu ya bayyana cewa yaduwar kwayar halitta tsakanin jinsuna ya bazu a lokacin juyin halitta na jinsunan bears masu rai.

 Sunayen 
Tun lokacin da aka gano a shekara ta 2006 ya sanya mahaukaci a cikin hasken wuta, kafofin watsa labarai sun ambaci wannan dabba tare da sunayen portmanteau da yawa, kamar su pizzly bear, grolar bear, , CBC North, April 26, 2006. da kuma polizzly, amma babu wata yarjejeniya game da amfani da ɗayan waɗannan kalmomin. Jami'an namun daji na Kanada sun ba da shawarar kiran mahaukaci "nanulak", wanda aka karɓa daga sunayen Inuit don beyar polar  (nanuk)  da grizzly bear  (aklak) . 

Ta hanyar wata yarjejeniya,  sunan sire ya zo da farko a cikin irin wannan haɗuwa: zuriyar beyar polar namiji da mace mai suna grizzly za su zama nanulak da aka ba da shawarar ko "beyar pizzly", yayin da zuriyar namiji mai suna griffly da mace mai laushi za su zama "beyar grolar" ko kuma yiwuwar aknuk.

 Halitta da aka kama 
An haifi 'ya'yan jariri biyu (mace daya da namiji daya) a Osnabrück Zoo a Osnabraück a shekara ta 2004, kuma halayensu na jiki suna tsakanin beyar polar da grizzly bear. Misali, jikinsu sun fi karami fiye da bears, amma sun fi girma fiye da grizzlies, yayin da kawunansu suka fada tsakanin babban kai mai laushi da kuma karamin kai na bears. Suna da wuyan wuyan wuyansa kamar bears, amma ƙananan kafadu kamar grizzlies. Takalma na ƙafafunsu an rufe su da gashi; bears na polar suna da takalma masu gashi, waɗanda ke aiki a matsayin mai rufewa, kuma grizzlies suna da takardu marasa gashi.

Hakazalika, gashin hybrids yana nuna alamar hollowness, wanda ya haɗu da halaye na bears da grizzlies. A cikin sashi, gashin bears yana da rami, yayin da gashin grizzlies ko dai yana da ƙarfi ko kuma yana da ƙananan yankuna masu rami. Wannan ya bambanta bisa ga wane ɓangare na gashi mai laushi ne aka ɗauke shi. A cikin namiji mai haɗari, gashin kafa yana da ƙarfi, amma gashin baya mai duhu yana da ɗan rami, duk da cewa yana da "ƙananan yankuna marasa amfani fiye da yadda aka samu a cikin gashin beyar polar". Gashi na mace mai haɗari, "ya ƙunshi kewayon yankuna masu zurfi".

Hybrids sun nuna halayyar da ta fi kama da bears fiye da grizzlies. Sun buga kayan wasa a hanyar da ta yi kama da yadda bears na polar suka karya kankara, kuma suka jefa jaka zuwa gefe "kamar yadda bears ke iya jefa ganima". Grizzlies da aka ba su jaka iri ɗaya ba sa nuna wannan halayyar jefawa. An kuma lura da hybrids suna kwance kamar yadda bears ke yi: a kan ciki tare da kafafu na baya.

Mace mai suna Tips, ta tsere daga kewaye da ita a watan Nuwamba na shekara ta 2017, kuma daga baya aka harbe ta har lahira; darektan gidan zoo Michael Boes ya yi tunanin cewa mai kwantar da hankali zai dauki minti 20 don yin aiki, ya kara da cewa "Mutuwar Tips babbar asara ce".

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