Ɗaya daga cikin tsoffin bambance-bambancen jinsin halittu da aka sani tsakanin mutane da chimpanzees mai yiwuwa ya taimaka wa tsoffin hominids, kuma yanzu mutanen zamani, sun yi nasara a kan nesa mai nisa. Don fahimtar yadda maye gurbin ke aiki, masana kimiyya sun bincika tsokoki na berayen da aka gyara ta hanyar kwayoyin halitta don ɗaukar maye gurbin. A cikin rodents tare da maye gurbin, matakan oxygen ya karu zuwa tsokoki masu aiki, ƙara ƙarfin hali da rage yawan gajiyar tsoka. Masu binciken sun ba da shawarar cewa maye gurbin zai iya yin aiki irin wannan a cikin mutane.
Yawancin gyare-gyare na physiological sun taimaka wajen sa ɗan adam ya fi ƙarfin gudu mai nisa: juyin halitta na dogayen ƙafafu, da ikon yin gumi, da asarar gashin gashi duk sun ba da gudummawa ga ƙara ƙarfin hali. Masu binciken sun yi imanin cewa "sun samo asali na farko na kwayoyin halitta don waɗannan canje-canjen da ba a saba gani ba a cikin mutane," in ji mai binciken likita kuma marubucin binciken Ajit Warki.
Halin da ake kira CMP-Neu5 Ac Hydroxylase (CMAH a takaice) ya canza a cikin kakanninmu kimanin shekaru miliyan biyu ko uku da suka wuce lokacin da hominids suka fara barin daji don ciyarwa da farauta a cikin babban savannah. Wannan shine ɗayan farkon bambance-bambancen kwayoyin halitta da muka sani game da mutane na zamani da chimpanzees. A cikin shekaru 20 da suka gabata, Varki da ƙungiyar bincikensa sun gano yawancin kwayoyin halittar da ke da alaƙa da gudu. Amma CMAH shine farkon kwayar halittar da ke nuna aikin da aka samu da sabon iyawa.
Duk da haka, ba duka masu bincike ne suka gamsu da rawar da kwayoyin halitta ke takawa a juyin halittar dan adam ba. Masanin ilimin halitta Ted Garland, wanda ya ƙware a fannin ilimin halittar ɗan adam a UC Riverside, ya yi gargaɗin cewa haɗin gwiwar har yanzu “zamantake ce” a wannan matakin.
"Ina matukar shakka game da bangaren ɗan adam, amma ba ni da shakka cewa yana yin wani abu ga tsokoki," in ji Garland.
Masanin ilimin halitta ya yi imanin cewa kawai duba jerin lokutan lokacin da wannan maye gurbi ya tashi bai isa a ce wannan kwayar halitta ta musamman ta taka muhimmiyar rawa a juyin halittar gudu ba.
Sauye-sauyen CMAH yana aiki ta hanyar canza saman sel waɗanda suka zama jikin ɗan adam.
"Kowane tantanin halitta na jiki an rufe shi gaba daya a cikin wani katafaren daji na sukari," in ji Varki.
CMAH yana rinjayar wannan saman ta hanyar ɓoye sialic acid. Saboda wannan maye gurbi, mutane suna da nau'in sialic acid guda ɗaya kawai a cikin dajin sukari na ƙwayoyin su. Yawancin sauran dabbobi masu shayarwa, ciki har da chimpanzees, suna da nau'in acid iri biyu. Wannan binciken ya nuna cewa wannan canjin acid a saman sel yana shafar yadda ake isar da iskar oxygen zuwa ƙwayoyin tsoka a cikin jiki.
Garland yana tunanin ba za mu iya ɗauka cewa wannan maye gurbi na musamman yana da mahimmanci ga ɗan adam ya rikiɗe zuwa masu tsere mai nisa. A ra'ayinsa, ko da wannan maye gurbi bai faru ba, wani maye gurbi ya faru. Don tabbatar da alaƙa tsakanin CMAH da juyin halittar ɗan adam, masu bincike suna buƙatar duba taurin sauran dabbobi. Fahimtar yadda jikinmu ke da alaƙa da motsa jiki ba zai iya taimaka mana kawai amsa tambayoyi game da abubuwan da suka gabata ba, har ma da samun sabbin hanyoyin inganta lafiyarmu a nan gaba. Yawancin cututtuka, irin su ciwon sukari da cututtukan zuciya, ana iya kiyaye su ta hanyar motsa jiki.
Don kiyaye zuciyar ku da tasoshin jini suna aiki, Ƙungiyar Zuciya ta Amurka ta ba da shawarar minti 30 na matsakaicin aiki kowace rana. Amma idan kuna jin wahayi kuma kuna son gwada iyakokin jikin ku, ku sani cewa ilimin halitta yana gefenku.