Juyin halitta da fifikon haɗin gwiwar ɗan adam

Tambayar juyin halittar mutum da dabba 

Juyin Halitta ya zama batu na mashahuran mahawara a cikin shekaru dari biyu da suka gabata. Da farko da misalan Colleen da Jane na zamani, muna iya ganin hadaddun hanyoyin da mutane suke sadarwa a halin yanzu. Akwai iƙirarin cewa ƴan adam sun fi kowa ci gaba a zamantakewa da sanin yakamata na kowane nau'in halitta a Duniya a yau saboda hasashen da muka samu na juyin halitta. Mutane da yawa sun yi imanin cewa waɗannan ikirari suna goyan bayan bayanan jijiya da ilimin halitta na haɗin gwiwar zamantakewar ɗan adam da yanke shawara tare da wasu nau'in ta amfani da ma'auni guda ɗaya na ɗan adam. Duk da haka, mutane na iya zama ba su kasance mafi sani da kuma ci gaban zamantakewa a cikin duniya.  

Juyin Halitta na pre-homo sapien da haɗin gwiwar zamantakewar ɗan adam na zamani 

Mutane suna ba da haɗin kai don dalilai masu yawa. Duk da haka, abin da ake ganin ya zama na musamman game da haɗin gwiwar ɗan adam shine cewa mutane suna da ikon wuce bambance-bambancen juna don tsira. Ana iya ganin misali ɗaya na wannan a cikin siyasar Amurka, inda mutane ke iya taruwa da sasantawa don ci gaba ba kawai tsira ba, amma ci gaba da nufin "ci gaba." A duniya baki daya, yana da ban sha'awa cewa kungiyoyi irin su Majalisar Dinkin Duniya sun hada kasashe daga ko'ina cikin duniya, duk da akida da akidu masu karo da juna, wajen cimma muradun bai daya.  

Don kwatanta takamaiman misali na yadda haɗin gwiwar zamantakewar ɗan adam ke da ƙarfi, bari mu ba da shawarar cewa Colleen ta shiga cikin aikin rukuni a aikinta wanda ke ɗaukar makonni na aiki da daidaitawa. Lokacin da aka gama aikin, Colleen da ƙungiyarta za su gabatar da shi a matsayin wani ɓangare na tayin kwangilar $1,000,000 - tayi mafi girma da aka taɓa samu a tarihin kamfaninta. Yayin da wannan aikin ya fi jin daɗi, Colleen yana da bambance-bambance na lokaci-lokaci tare da abokan aikinta. Colleen da ƙungiyarta sun gabatar da tayin kuma sun ƙare cin nasarar kwangilar rikodin rikodin. A cikin wannan misali, rashin jituwar Colleen da abokan aikinta ya fi karfin kwangilar kwangilar da aka yi nasara da fa'idojinta. 

Koyaya, matakan haɗin gwiwa sun bambanta a cikin ɗan adam. Jane, wacce ba ta da haɗin kai, ta girma a cikin gidan da sadarwa ba ta da tasiri sosai, kuma dangin ba su taɓa yin aiki tare don shawo kan bambance-bambance da shinge ba. Jane ta haɓaka haɗin gwiwa mara kyau tare da haɗin gwiwar zamantakewa saboda kwarewarta a matsayin yarinya. 

Bambance-bambancen da ke tsakanin labarun mata biyu za a iya bayyana shi tare da hujjar yanayi da kuma rayarwa. Wadanda ke tare da dabi'a sun ce kwayoyin halitta sune dalilin farko na ayyukan mutum. Waɗanda suke tare da renon yara suna cewa yanayin mu shine ke ƙayyade tunaninmu da ayyukanmu. A cewar Dokta Dwight Kravitz na Jami’ar George Washington, tare da wasu masana da dama, wannan gardamar ba ta taso a cece-kuce ba saboda yanayin ci gaban mutum yana da tasiri a kan dabi’u da tarbiyya, da kuma yiwuwar ma wasu abubuwa da ba mu sani ba tukuna. 

Yanzu da muka yi nazarin haɗin gwiwar zamantakewa tare da mutanen zamani, bari mu bincika haɗin kai da juyin halitta kafin homo sapien. Shaidu na baya-bayan nan sun nuna cewa masana tarihi da na binciken ɗan adam sun sami damar sake gina ƙa'idodin zamantakewa a cikin al'ummomin pre-homo sapien inda nau'ikan nau'ikan hominids suka rayu. Haɗin kai wani bangare ne na ayyukan ɗan adam wanda da alama yana dawwama tun ma kafin mutane su ketare "layi" daga Australopithecus zuwa homo. Haɗin kai wani aiki ne da za a iya lura da shi a cikin al'umma a tsakanin halittu, gami da dabbobi da mutane, akan ilimin halitta, ko abin da nake ƙirƙira ta asali, ko tushen zamantakewa/jiki. Duk da haka, mutum zai iya jayayya cewa waɗannan nau'o'in haɗin gwiwar ba iri ɗaya ba ne. Ba ma a cikin al'amuran mutane da na gabanin mutane ba za a iya jayayya cewa haɗin gwiwa ya kasance iri ɗaya na tsawon lokaci a cikin mahallin manufa da rikitarwa. Idan har muka ɗauka cewa ’yan Adam na farko suna da ƙarin ilhami na “tsohuwar”, za mu ga yadda buƙatun haɗin gwiwa kuma na iya zama daɗaɗɗe, kamar ɗabi’ar abokin aure ko farauta, idan aka kwatanta da haɗin kai na zamani, kamar zartar da doka a cikin gwamnati, ko kuma. ayyukan ƙungiyar haɗin gwiwa. Idan aka yi la’akari da irin wannan gardama da kuma sakamakon yanayi da husuma, tambayar da ke tasowa ita ce, ta yaya ake buqatar hadin kai da farko?  

Tushen jijiya don juyin halittar haɗin gwiwar zamantakewa 

Yayin da shari'ar Colleen na iya nuna yadda za a iya ƙarfafa haɗin gwiwa a kan matakin phenotypic ma'ana za a iya lura da shi ta jiki-ana kuma iya yin nazari akan matakin ilimin halitta tare da tsarin dopaminergic a cikin kwakwalwa. Kamar yadda Kravitz ya faɗi, "tsarin dopamine yana haɗawa a cikin madauki inda aka aika da sigina masu kyau a cikin tsarin limbic da prefrontal, suna samar da motsin rai / ƙwaƙwalwar ajiya da lada horo, bi da bi." Lokacin da aka saki dopamine a cikin kwakwalwa, ana iya samar da siginar lada ta nau'i daban-daban. A cikin yanayin Jane, idan dopamine shine farkon neurotransmitter wanda ke da alhakin siginar lada, abin da zai faru lokacin da samar da dopamine ya daina, ko kuma ya ragu na ɗan lokaci, saboda wani mummunan yanayi ko yanayi, kamar a cikin yanayin Jane. Wannan karya a cikin dopamine yana da alhakin ƙirƙirar ƙiyayyar ɗan adam, tsoro, damuwa, da sauransu. A game da Jane, mummunan haɗin gwiwar haɗin gwiwa saboda maimaita raguwa a cikin dopamine lokacin ƙoƙarin yin haɗin gwiwa tare da danginta tun tana yarinya ya sa ta yiwu ba ta da kwarin gwiwa don yin haɗin gwiwa. Bugu da ari, za mu iya ganin cewa ana iya lura da haɗin gwiwa a kan matakin neurological a cikin mutane na zamani kamar Colleen da Jane kamar yadda Gwaje-gwajen kwanan nan waɗanda suka mayar da hankali kan tasirin dabarun abokan hulɗa sun bincika kunnawa daban-daban a cikin dorsolateral prefrontal cortex (DLPFC) lokacin wasa tare da wakilan ɗan adam waɗanda ke ba da haɗin kai, tsaka tsaki, da rashin haɗin gwiwa […] aiki na cin nasara karbuwa zuwa ga dabara/masu dabara na jami'an kwamfuta […]."  

Yana iya zama yanayin cewa wasu mutane kawai suna samar da ƙarancin dopamine, ko kuma suna da ƙarancin masu karɓar dopamine don sake dawo da dopamine.  

Wani bincike kan haɗin kai da gasa, wanda NIH ta gudanar, ya nuna cewa "haɗin kai tsari ne mai lada ga zamantakewa kuma yana da alaƙa da takamaiman sa hannun hagu na kobitofrontal cortex na hagu." Yana da ban sha'awa a lura cewa orbitofrontal cortex shima yana da hannu sosai a cikin siginar sakamako wanda a ƙarshe yana haifar da kuzari. Waɗannan abubuwan da suka faru na halitta suna zagaye-zagaye kuma suna da tasiri daban-daban akan halayen mutane. A cewar W. Schultz, "haɗin gwiwa tsakanin siginonin lada daban-daban na iya tabbatar da amfani da takamaiman lada don zaɓin ƙarfafa ɗabi'a." Akwai shaida cewa haɗin gwiwa yana ƙarfafa lokacin da ya haifar da lada. A duk lokacin da sakamako mai kyau ya fito daga haɗin gwiwa, mai yiwuwa ne yanayin da neurotransmitter, dopamine, ya fito. Lokacin da wannan ya faru, duk abin da ya kai ga aikin yana ƙarfafawa. Ba shi da tabbas menene ainihin matakan dopamine na pre-homo sapiens, don haka nazarin ilimin jijiya na Colleen da Jane sun fi bayyana dalilin haɗin gwiwar ɗan adam na zamani. Duk da yake akwai lokuta da yawa kamar na Jane da ke adawa da sakamakon gaba ɗaya na irin wannan tsarin lada, mun san mafi yawan jama'ar zamani na zamani kamar Colleen ne. 

Amygdala wani muhimmin tsarin bran ne a cikin nazarin haɗin gwiwar ɗan adam. An yi imanin amygdala ya dace da yanayin zamantakewa kuma shine "An nuna ya zama dole don samun yanayin jin tsoro na Pavlovian, amma kuma ya zama mahimmanci don koyon jin tsoron abin kara kuzari kawai ta hanyar lura da wani mutum ya fuskanci sakamakonsa[…]." Ragewar amygdala ana jayayya cewa yana da alaƙa da raguwar tsoro a cikin masu laifi. Koyaya, an sami ƙarancin binciken hoto na kwakwalwa akan amygdala kuma babu wata shaida da ke nuna waɗanne yankuna a cikin amygdala za a iya daidaita su cikin tsari a cikin mutane masu ilimin halin dan Adam.  

Yanzu, menene wannan yake nufi ga bincikenmu na ’yan adam na farko? Tabbas, ba mu da wani kwakwalwa na zahiri na farkon hominids don aunawa da nazari. Koyaya, bisa ma'auni na ragowar cranial da muka sami damar ganowa, zamu iya kimanta girman girman wasu sassan kwakwalwa. Bugu da ƙari, muna kuma iya yin nazarin tsarin kwakwalwa na firfimate na zamani. Girman kwakwalwa da siffar kwanyar Australopithecus yayi kama da na chimpanzee; duk da haka, ba mu san ainihin nauyin ba, ko “ƙarfin cranial.”  A cewar gidan tarihi na Smithsonian National Museum of History, da "Matsakaicin nauyin kwakwalwar chimpanzee babba [yana] 384 g (0.85 lb)" yayin da "matsakaicin nauyin kwakwalwar ɗan adam na zamani [yana] 1,352 g (2.98 lb)." Idan aka ba da bayanan, za mu iya ganin cewa canje-canje a cikin girman amygdala na iya haɗuwa da haɓaka ƙarfin fahimta a cikin haɗin gwiwar zamantakewa a lokacin juyin halittar ɗan adam. Bugu da ƙari, wannan yana nufin cewa haɓaka girma da ƙarfin duk tsarin kwakwalwa masu dacewa na iya haɗuwa da haɓaka, ko ci gaba, fahimtar zamantakewa da haɗin kai.