Indlela ipipi elahla ngayo izikhala zayo
Abantu bajikijela iDNA ukuvela ngamalambu abushelelezi nobuchopho obukhulu.
Ezocansi kungaba isiphakamiso esehluke kakhulu kubantu uma - njengezilwane ezithile kufaka phakathi chimpanzee, ama-macaque kanye namagundane - amadoda abenezinhlaka ezihlanganisiwe ezinezinsimbi ezincane, ezinzima.
Manje abaphenyi baseStanford University eCalifornia bathole indlela yamangqamuzana okuthi i-penis yomuntu yavela kanjani ukuba ihlukane nomgogodla. Bakuvezile njengokulahleka kwe-chunk ethile ye-DNA engabhalisi okuthonya ukubonakaliswa kohlobo lwe-androgen receptor oluhilelekile ekusayineni kwe-hormone.
"Kuyingxenye encane kodwa ekhangayo yesithombe esikhulu mayelana nokuvela kwezici eziqondene nabantu," kusho uGill Bejerano, isazi sezinto eziphilayo esithuthukayo eStanford owahola lo msebenzi nozakwabo uDavid Kingsley. "Sifaka umbono wengqamuzana engxoxweni ebiqhubeka okungenani amashumi eminyaka okungenani."
Ishicilelwe ku-Nature namuhla1, ucwaningo luphinde luveze indlela yokusebenza kwamangqamuzana ngendlela esivele ngayo sasebenza ngobuchopho obukhulu kunamashimpanzi futhi saphulukana nemilingo emincane yezinzwa ukuthi imveku - ephakathi kwezihlobo zethu eziseduzane futhi okulinganiselwa ukuthi sabelana nge-96% ye-DNA yethu - ubuso.
Isu lokuqapha
Kudala bekukholelwa ukuthi abantu bavela njengemidwebo ebushelelezi ngenxa yokuthatha isu lokuzala elingashisi kunelokhokho babo bokuqala abangabantu. Labo madlozi kungenzeka basebenzise imisipha ye-penile ukususa isidoda sabaqhudelanayo lapho bekhula nabesifazane. Kodwa-ke, ukuthi kwenzeka kanjani ngempela lolu shintsho alwaziwa.
Abaphenyi abazimisele ngokufunda izikhala zemvelo. Esikhundleni salokho, babefuna ama-chunks e-DNA ayelahlekile ku-genome yomuntu kodwa hhayi i-chimp genome, ngakho-ke bangazama ukukhomba lokho okwenziwe yilawo ma-chunks.
Le ndlela yehlukile kunaleyo ezifundweni eziningi, chaza uBejerano noKingsley, ekubukeni okususiwe kufuzo lomuntu kunalokho okukhona. "Endabeni yokutadisha kwethu, ukube uqale kusukela kuzakhi zofuzo zomuntu, ngabe akukho lapho ongabona khona," kusho uBejerano.
Baqala ngokulandelana kokulandelana kwe-510 DNA ukulandelana okulahlekile kubantu futhi bekhona kuma-chimps, bathola ukuthi lokho kulandelana cishe kwakuvela kuphela ezingxenyeni ze-genome ezingekho amakhowudi, phakathi kwezakhi zofuzo. Base bekhombisa ukulandelana okubili ukungabikho kwabo kubantu abacabanga ukuthi kungahle kuthakazelise - okukodwa kusuka eduzane ne-androgen receptor (AR) noyedwa osondelene nofuzo obandakanyeka ekucindezelweni kwe-tumor (GADD45G).
Ukufaka uhlelo lokulandelana kwama-chimpanzee kwimibungu yegundane kwaveza ukuthi ukulandelana kwangaphambilini kwaveza zombili izinhlayiya zobulukhuni obulukhuni kanye nezimpondo zezinzwa ezikhona kwezinye izilwane. Ukulandelana kokugcina kusebenza njengendlela yokuqhekeka ekukhuleni kwezifunda ezithile zobuchopho - ngokususwa komsebenzi wawo kubonakala sengathi kuvimbe indlela yokuvela kobuchopho obukhulu bomuntu.
"Inhloso yalo msebenzi bekuwukuthola izilonda zamangqamuzana [ezilahlekile] ezisekela izici zomuntu zokuziphendukela kwemvelo, nezibonelo ezibonisa izici ezahlukahlukene zalo mgomo," kusho uKingsley.
"Kuze kube yilapho sibheka lapho i-DNA ivezwa khona, besingazi ukuthi iyiphi ishintshi - uma ikhona - ezolawula empeleni," kwengeza uBejerano.
Ezinye izazi zesayensi yamangqamuzana zincome lo msebenzi ngendlela yawo ekhaliphile futhi zithi zizovula izindlela ezintsha zokubuza, ikakhulukazi kulabo abasebenza ekudalekeni kobuchopho bomuntu.
"Kungumsebenzi wabaseshi futhi uyisikhumbuzo esikhulu sokuthi, ngesikhathi sokuziphendukela kwemvelo, ulwazi luyatholakala futhi lilahleke," kusho uSean Carroll, onguchwepheshe kwezofuzo lwezilwane nokuziphendukela kwemvelo e-University of Wisconsin, eMadison.
"Njengoba kuvame ukuba nemibono emihle kakhulu, kubonakala kucace uma ubheka emuva," kusho uSvante Pääbo, oqondisa umnyango wezofuzo weMax Planck Institute for Evolutionary Anthropology eLeipzig, eJalimane, futhi ebeyingxenye yethimba elisanda kulandelela iNeanderthal ufuzo. "Njengoba ukulandelana okubili okususiwe okungaba ngu-500 abakukhombe kuvela ukuthi kuyathakazelisa, ngiyaqiniseka ukuthi ezinye eziningi ezisohlwini lwabo nazo zizoba mnandi," engeza. Abaphenyi bayaqhubeka nokuhlaziya ukulandelana okusele kwe-DNA okungama-508.
UDavid Haussler, ocwaninga ngokuziphendukela kwamangqamuzana e-genome yomuntu eNyuvesi yaseCalifornia, eSanta Cruz, wengeze ngokuthi ukulahleka kokhokho bethu be-penile spines kuyinzuzo yethu namuhla. ”Imibhangqwana yonke indawo ingabonga ukuthi le ngxenye ethile ye-DNA yachitheka, " uthi.
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