https://www.sciencedaily.com/releases/2013/09/130909172056.htm
Abesilisa abanezivivinyo ezincane kunabanye kungenzeka ukuthi babambe iqhaza ekunakekeleni izingane zabo, ucwaningo olusha olwenziwe yi-anthropologists e-Emory University luthola. The Izinqubo ze-National Academy of Sciences (I-PNAS) kushicilelwe imiphumela yocwaningo lwe-Sep. 9.
Amavolumu amancane ama-testicular abuye axhumane nomsebenzi wobuchopho ohlobene nokunakekela obaba njengoba bebheka izithombe zezingane zabo, ucwaningo lubonisa. "Imininingwane yethu iphakamisa ukuthi i-biology yabantu besilisa ikhombisa ukungahambisani phakathi kokutshalwa kwezimali ekuzameni kokuqhathanisa nemizamo yokuba ngumzali," kusho u-Emory isazi sethambo uJames Rilling, owenziwe ilabu lakhe ucwaningo.
Inhloso yocwaningo ukuthola ukuthi kungani abanye obaba betshala amandla amaningi ekukhuliseni abazali kunabanye. "Ngumbuzo obalulekile," kusho uRill, "ngoba izifundo zangaphambilini zikhombisile ukuthi izingane ezinobaba abaningi abathintekayo zinomphumela ongcono wenhlalo, ngokwengqondo nangokwezemfundo."
Umlando Wokuphila Kwokuziphendukela Kwemvelo uveza ukuthi ukuziphendukela kwemvelo kukhulisa ukwabiwa kwezinsiza ngokuya kokuzala noma ukuba ngumzali ukuze kukhuliswe ukuqina. "Ucwaningo lwethu ngolokuqala ukuphenya ukuthi ngabe ukuqina komzimba womuntu kanye nobuchopho kuyakuchaza yini lokhu kwehluka emzameni wokuba ngumzali," kusho uJennifer Mascaro, ohole lolu cwaningo njengomuntu owayengudokotela wakhe kwelebhu yeRiling.
Ngenkathi izici eziningi zezomnotho, zenhlalo nezamasiko zingaba nomthelela ezingeni likababa ekunakekeleni, abacwaningi babefuna ukuphenya ukuxhumana okungenzeka kokuzalwa.
Babazi ukuthi amazinga aphansi e-testosterone emadodeni ahlanganiswe nokubandakanyeka okukhulu kakhulu kobaba, nokuthi amazinga aphezulu e-hormone abikezela isehlukaniso kanye nesithembu.
Ama-testes, ngaphezu kokukhiqiza i-testosterone emadodeni, nawo akhiqiza isidoda. "IVolumu yovivinyo ihlangana kakhulu nokubalwa kwesidoda nekhwalithi kunamazinga e-testosterone," kusho uMascaro.
Lolu cwaningo lufake phakathi obaba bemvelo be-70 ababenomntwana phakathi kweminyaka ye-1 ne-2, futhi ababehlala nengane nonina wayo.
Omama nobaba kwaxoxwa nabo ngokwahlukana mayelana nokubandakanyeka kukababa ekunakekelweni kwezingane, kufaka phakathi imisebenzi efana nokushintsha izimbotshana, ukondla nokugeza ingane, ukuhlala ekhaya ukunakekela ingane egulayo noma ukuyisa ingane ukuvakashelwa udokotela.
Amazinga e-testosterone abesilisa alinganiswa, futhi atholakala ku-imagon resonance imaging (fMRI) yokusebenza ukulinganisa umsebenzi wobuchopho njengoba bebuka izithombe zengane yabo ngezinkulumo ezijabulisayo, ezidabukisayo nezingathathi hlangothi, nezithombe ezifanayo zomntwana ongaziwa nomuntu omdala ongaziwa. Ngemuva kwalokho, i-MRI yesakhiwo yayisetshenziselwa ukukala ivolumu ye-testicular.
Okutholakele kukhombisa ukuthi womabili amazinga we-testosterone nosayizi wama-testes ahlanganiswe ngendlela enobunzima nenani lokunakekelwa okuqondile kotata okubikwe ngabazali ocwaningweni.
Futhi ivolumu yokuhlolwa kukababa ibuye ihambisane nomsebenzi endaweni ye-ventral tegmental endaweni (VTA), okuyingxenye yohlelo lobuchopho oluhlotshaniswa nomvuzo nogqozi lwabazali. "Abesilisa abanezivivinyo ezincane bebesebenza kakhulu kule ndawo yobuchopho uma bebheka izithombe zengane yabo," kusho uMascaro.
Ngenkathi amazinga we-testosterone engahle ahlobane kakhulu nokuncintisana kwangaphambi kokushicilela, ukuqondisisa okungaphakathi, ivolumu ye-testicular ingakhombisa ukutshala imali kokuzalela ngemuva kokushicilela, abacwaningi bona.
Noma zibalulekile ngokwezibalo, ukuxhumana phakathi kosayizi wama-testes nokunakekela bekungaphelele.
"Iqiniso lokuthi sithole lokhu kwehlukahluka libonisa ukuzikhethela," kusho uRill. “Noma amanye amadoda engakhiwa ngendlela eyehlukile, mhlawumbe azimisele ukuba nobaba abaningi. Kungaba inselelo ngokwengeziwe ukuthi amanye amadoda enze lezi zinhlobo zemisebenzi yokunakekela izingane, kodwa lokho akunakuba yizaba. ”
Umbuzo oqakathekile ophakanyiswe yilokhu okutholakele ocwaningweni ukuqondiswa kwengozi. “Sicabanga ukuthi usayizi we-testes ushayela ukuthi ababambe iqhaza kanjani obaba,” kusho uRill, “kepha kungenzeka futhi ukuthi lapho amadoda ehlanganyela kakhulu njengabanakekeli, izivivinyo zawo ziyancipha. Amathonya ezemvelo angashintsha i-biology. Siyazi, ngokwesibonelo, ukuthi amazinga e-testosterone ehla lapho amadoda ehlanganyela kobaba. ”
Omunye umbuzo obalulekile ukuthi imvelo yezingane ingathinta usayizi wama-testes. "Olunye ucwaningo luye lwabonisa ukuthi abafana abanengcindezi yokubelethwa kwengane bayashintsha amasu abo okuphila," kusho uRill. "Noma mhlawumbe abafana abangenayise basabela ekuthini bengekho ubaba wabo ngokuthatha isu eligcizelela ukuzikhandla kokuzala ngenxa yemizamo yokuba ngumzali."
Ucwaningo lwalugxile kuphela ekunakekelweni kotata okuqondile, hhayi izindlela zokunakekelwa eziqondile, njengokuvikela izingane nokuthola imali yokuziphakela.
Emashumini eminyaka edlule ama-1960s, inani labesifazane abakhulisa izingane bebodwa e-United States likhuphuke kakhulu. "Yize kunemindeni eminingi engenabo obaba, lapho obaba sebekhona, bavame ukubamba iqhaza kakhulu kunaseminyakeni edlule," kusho uMascaro.
Iningi lezincwadi zesayensi ezikhona ekukhuliseni zigxile kumama, amanothi weRill. "Omama banomthelela omkhulu ekukhuleni kwezingane, kepha obaba nabo babalulekile futhi indima yabo iyaqhanyelwa."
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