Ƙaddamar da jima'i na muhalli

Ƙaddamar da jima'i na muhalli shine kafa jima'i ta hanyar alamar da ba ta kwayar halitta ba, kamar wadatar abinci mai gina jiki, wanda aka samu a cikin wani lokaci mai hankali bayan taki. Abubuwan muhalli waɗanda galibi suna tasiri ga ƙaddamar da jima'i yayin ci gaba ko balaga na jima'i sun haɗa da ƙarfin haske da lokacin daukar hoto, zafin jiki, wadatar abinci mai gina jiki, da pheromones da tsire-tsire ko dabbobi ke kewaye da su. Wannan ya bambanta da ƙaddamar da jima'i na jinsi, wanda ke kafa jima'i a lokacin haihuwa ta hanyar abubuwan kwayar halitta kamar su chromosomes na jima'i. A karkashin ainihin ƙudurin jima'i na muhalli, da zarar an ƙaddara jima'i, an gyara shi kuma ba za a iya sake sauyawa ba. Ƙaddamar da jima'i na muhalli ya bambanta da wasu nau'o'in hermaphroditism na tsari wanda aka ƙaddara jima'i a hankali bayan haihuwa a duk rayuwar kwayar halitta.

 Ma'anar daidaitawa 
Ƙididdigar jima'i na muhalli yayi kama da wasu nau'ikan zaɓin jima'i domin akwai lokuta daban-daban da adawa da matsa lamba akan maza da mata saboda tsadar haifuwa.  Zaɓin jima'i ya zama ruwan dare a cikin bishiyar rayuwa (wanda aka fi sani da tsuntsaye);  sau da yawa yana haifar da dimorphism na jima'i, ko girman da bambance-bambancen kamanni tsakanin jinsin jinsi ɗaya.[1]  A cikin ƙayyadaddun ƙayyadaddun jima'i na muhalli, matsananciyar zaɓi akan lokacin juyin halitta sun zaɓi don sassauci a cikin ƙudurin jima'i don haɓaka dacewa a cikin yanayi daban-daban saboda tsadar jima'i daban-daban a cikin maza da mata.[2]  Wasu yanayi na muhalli sun bambanta da kowane jinsi ta yadda zai kasance da amfani ya zama jinsi ɗaya ba ɗayan ba[3].  Wannan yana da mahimmanci musamman ga kwayoyin halitta waɗanda ba za su iya motsawa zuwa wani yanayi na daban ba.  A cikin tsire-tsire, alal misali, aikin jima'i na mace ya fi tsada da kuzari saboda da zarar an yi takin dole ne su yi amfani da makamashi mai mahimmanci don samar da 'ya'yan itatuwa, tsaba, ko sporophytes yayin da maza za su samar da maniyyi kawai (da kuma tsarin da ke dauke da maniyyi; antheridium a cikin tsire-tsire marasa iri, da pollen a cikin tsire-tsire iri).

 Hanyoyin da ake amfani da su 
Rashin ƙididdigar bayanan kwayar halitta don jinsi daban-daban kamar su chromosomes na jima'i, mutanen da ke nuna ƙudurin jima'i na muhalli suna ƙunshe da ƙididdigan bayanan kwayar cuta ga maza da mata a kan autosomes. Gabaɗaya, da zarar an fallasa su ga wasu alamun muhalli, Canje-canje na epigenetic suna haifar da mutane masu tasowa su zama namiji ko mace. Alamun muhalli waɗanda galibi ke haifar da ci gaban maza ko mata sun haɗa da zafin jiki, abinci mai gina jiki (ko abinci a yanayin dabbobi) da wadatar ruwa, photoperiod, damuwa ta gasa, da pheromones daga mutane masu kama da juna. Takamaiman hanyoyin da alamomi sun bambanta tsakanin jinsuna.

 Yankin lissafi 

 Dabbobi masu kama da dabbobi 
amphipod crustacean Gammarus duebeni yana samar da maza da wuri a lokacin jima'i, kuma mata daga baya, don mayar da martani ga tsawon hasken rana, lokacin daukar hoto. Saboda lafiyar namiji tana inganta fiye da lafiyar mace tare da karuwar girman, ƙaddamar da jima'i na muhalli yana daidaitawa a cikin wannan tsarin ta hanyar ba da izinin maza su sami lokacin girma fiye da mata.

Branchiopod crustacean Daphnia magna parthenogenetically yana samar da zuriyar namiji don mayar da martani ga haɗuwa da dalilai uku na muhalli, wato rage lokacin daukar hoto a cikin kaka, karancin abinci da yawan jama'a.

 Annelids 
Bonellia viridis, tsutsotsi ne na ruwa, yana da ƙudurin jima'i na wurin; jima'i ya dogara da inda tsutsotsi suka sauka.

 Dabbobi masu ƙashi 
Jima'i na mafi yawan dabbobi masu shayarwa, kamar dabbobi masu rarrafe da tsuntsaye, an ƙaddara su ta hanyar kwayar halitta. Koyaya, wasu dabbobi masu rarrafe suna da ƙudurin jima'i na dogara da zafin jiki, inda jima'i ya ƙayyade har abada ta yanayin zafi da aka samu a lokacin tsakiyar kashi uku na ci gaban tayin. Jima'i na crocodilians da Sphenodontians an ƙayyade su ne kawai ta hanyar zafin jiki. Sabanin haka, squamates (tsuntsaye da macizai) da Turtles suna nuna ƙudurin jima'i na genotypic da ƙudurin jinsi na dogara da zafin jiki, kodayake dogaro da zafin ya fi yawa a cikin turtles fiye da squamates.
Yawancin nau'in fern (tare da wasu 'yan kaɗan, watau Salvineales) suna da ɗanɗano kuma basu da chromosomes na jima'i.  Rashin bayanan bayanan kwayoyin halitta don jinsi daban-daban, kowane spore na fern yana da ikon zama namiji, mace, ko hermaphroditic gametophyte dangane da muhalli.[1][2]  A yawancin nau'in fern, ciki har da Ceratopteris richardii, ƙaddarar jima'i na muhalli yana da alaƙa da tsarin kiwo.[3]  Fern gametophytes suna nuna nau'ikan tsarin nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in iri da nau'in nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan ma'adinai) suna da nau'ikan da za'a iya rarraba su zuwa raye-raye da raye-raye.  Don haɓaka wuce gona da iri, gametophytes na mata suna fitar da sinadari pheromone da aka sani da Antheridiogen wanda ke sarrafa jima'i na gametophytes masu tasowa na kusa.[4]  Antheridiogen da mata ke ɓoye yana haɓaka haɓakar gametophytes na asexual a kusa da maza.  Wannan yana daidaitawa saboda haifar da namiji yana ƙara yuwuwar wucewa yayin da maza ke ba da maniyyi ga mata maimakon mata su zama hermaphroditic (ko bisexual) da taki da kansu.  Duk da haka, idan ba hadi ya faru ba, gametophyte na mace zai iya zama hermaphroditic kuma ta yi kanta idan yanayin ya dace da girma, a ƙarshe yana haifar da rashin tausayi.

Bugu da ƙari, kama da crocodilians, jima'i na homosporous fern gametophyte an ƙayyade shi ta hanyar yanayin abiotic daidai da tsarin girman-advantage. A cikin yanayin damuwa (crowding ko damuwa mai gina jiki), gametophytes sun fi karami kuma sun bunkasa zuwa maza. Duk da yake a cikin yanayin girma mafi kyau, gametophytes sun fi girma kuma sun bunkasa zuwa mata.
Moss gametophytes na iya zama ko dai asexual, mace, namiji, ko hermaphroditic kamar ferns. Ba kamar homosporous ferns ba, moss gametophytes na iya zama ko dai monoicous ko dioicous (kamar monoecious da dioecious a cikin tsaye-tsire na vascular), tare da mafi yawan nazarin nau'in dioicous da ke nuna ƙudurin jima'i ta hanyar tsarin ƙudurin jinsi na UV. Wasu nau'o'in moss irin su Splachnum ampullaceum suna nuna ƙudurin jima'i na muhalli a lokacin farkon ci gaba, tare da ƙarancin haske, ƙarancin pH, da ƙarancen abinci mai gina jiki duk suna inganta ci gaban namiji. A gaban auxin, hormone mai yaduwa, ko gibberellins, mahadi masu kama da Antheridiogen a cikin ferns, duka mata da maza suna saka hannun jari a cikin tsarin jima'i (antheridia da Archegonia).  Ƙaddamar da jima'i na muhalli a cikin moss ya bambanta da rarrabewar jinsi, faruwar daidaitattun jima'i da ke cikin muhalli, wanda aka lura a cikin nau'ikan moss masu jima'i. Rarrabawar maza da mata a cikin mosses ya haifar da bambancin rayuwa tsakanin maza da mata sakamakon fa'idar gasa na moss mata. Wannan yana haifar da yawan mata da ke ci gaba da haihuwa ta hanyar haihuwar jima'i da ƙananan haihuwar jimaʼi. Sabanin haka, ƙaddamar da jima'i na muhalli shine ci gaban mata ko maza a cikin yanayin muhalli daban-daban.
Yawancin angiosperms suna nuna hermaphroditism na tsari, ma'ana cewa suna iya canza jima'i a kai a kai a duk rayuwarsu bisa ga yanayin yanzu da wadatar albarkatu don inganta lafiya kowane lokacin fure. Amma hermaphroditism na tsari da ƙaddamar da jima'i na muhalli ba su da alaƙa da juna. Misali, Catasetum viridiflavum, wani epiphyte (tsire-tsire da ke girma a kan wani shuka) a cikin iyalin Orchidaceae yana nuna hermaphroditism na tsari inda matasa, ƙananan mutane suna da inflorescences na namiji kuma tsofaffi, manyan mutane suna da intlorescencences na mata, amma bayyanar jima'i ma tana da tasiri sosai ta hanyar haske. Mutanen da ke cikin haske mai haske galibi mata ne kuma mutane a cikin haske mai sauƙi galibi maza ne, ba tare da la'akari da girman ba. A cikin haske mafi girma, mutane suna samar da ƙarin ethylene, hormone na shuka na yau da kullun, wanda ke inganta samar da furanni mata.
Rukuni:Shafuka masu fassarorin da ba'a duba ba