Canzawar al'ummomi - shi ne ... The canzawar al'ummomi, a tsire-tsire

A duniya ta yau hakan ya zama al'ada kira fasaha sharuddan duk abin da na kewaye da mu. haifuwa inji ... Wannan dama, "lakabin" kimiyya zukatan mu'ujiza na sabon rai.
Miracle, a cikin abin da kowane bangaren shi ne don haka jitu, bambancin da kuma a lokaci guda shi ne makawa, cewa wani lokacin daya iya kawai abin mamaki. Mutane da yawa dubban shekaru mutãne ya racked su tarar da kwakwalwarmu a kan wannan tambaya da primacy na qwai da kaza, kuma suna da yanayi na dogon lokaci shi ne amsar duk tambayoyi. Rationalism kuma da dama mafita a tsare da kwanciyar hankali na mutum jinsunan kuma, a lokaci guda ãyõyin bambancin saye a cikin yanayi ne unmatched.

A kayyade tushen rayuwa

Daya daga irin wannan na'urorin ne sãɓawar zamaninsu. A bambancin da dabba da shuka rayuwa da aka samu ta hanyar halittar daban-daban haduwa da kwayoyin abu. Canzawar al'ummomi - shi ne na musamman nau'i na jinsin kiyayewa a canza waje muhalli, shi ne mafi yawa samu a dama shuke-shuke da ƙananan kwaro. Yana da wani canji na jima'i da kuma sake yiwuwar tohowarsu. Abin da ya haddasa da ƙaddamar da wani musamman Hanyar haifuwa da kuma abin da kwallaye da suka bi? Don amsa wannan tambaya kamata more warai fahimci abin da suke da bambance-bambance tsakanin jima'i da kuma sake yiwuwar tohowarsu, abin da suke da amfani ga jinsuna da kuma rashin amfani da suka kawo.

syngenesis

A tsari na jima'i haifuwa ya shafi, a cikin halittar wani sabon rayuwa na biyu mutane da suka yi, kowa a kanta, suna dako na nasu mutum sets na chromosomes a cikin DNA biyu Helix sarkar. Wannan sa na musamman da kwayoyin abu da aka bayyana a gaban mutane a cikin art, da kuma kawai ta, wasu siffofin da shi partially watsa ta zuriyarsa.

Tare da sa hannu a kan aiwatar da jima'i haifuwa na mutane biyu, kowanne daga abin da ba a yuwuwar gaje irin rabin-sa na chromosomes, na gaba tsara za a halin da siffofin duka biyu iyayentaka kwayoyin. Wannan shi ne dalilin da ya sa akwai wani canzawar a zamaninsu, kamar yadda a cikin sauki da kuma a cikin hadaddun siffofin rayuwa, dauke da haifuwa saboda jima'i haifuwa.

Abin da taimako ga gene pool jinsin sa jima'i haifuwa

Ko a cikin gwada da kananan yawan mai sa na kayyade kayan haduwa iya zama rashin iyaka m. Wannan irin kiwo bin manufar gabatar da bambanci a kayyade bango jinsin jama'a. Diversity kuma za a iya samu ta hanyar yin amfani da alƙarya cikin kafa sabon lokutta na wani ba jinsin, wadda a hanyoyi daban-daban za su iya shiga daga waje. Ko ta yaya, misali, shuke-shuke ko wasu coelenterates, saboda jam sel "home delivery" tare da taimakon iska, ruwa, ko kwari.

An muhimmin batu a jima'i haifuwa wajibi ne don nuna yiwuwar sa hannu a cikin yawanci lafiya kuma mafi iko mutane. Saboda haka, irin wannan haifuwa damar aiwatar da zabin yanayi, wanda na taimaka wa yiwuwar kayyade ãyõyin aiki ga mai kyau na jinsi.

Sake yiwuwar tohowarsu, kamar yadda yawan mutane multiplier dabara

canzawar al'ummomi - wani tsarin da aka yi amfani da ƙara da kuma adana daga cikin jinsunan, a cikin abin da muhimmanci rawa da sake yiwuwar tohowarsu. Na da abũbuwan amfãni iya amince ambaci yiwuwar hanzari kara yawan size karkashin m ga wannan nau'in na muhalli da yanayi. Adana da kuma kara da kwayoyin stock na yawan amfani da mahara cloning data kasance haduwa da kwayoyin halittu, wanda muhimmanci ƙara samu damar jinsunan a hannu na wadannan haduwa a nan gaba jima'i haifuwa.

Canzawar phenotypes a daban-daban sammai

Canzawar ƙarnõni na algae dogara a kan zafin jiki bango, da sinadaran abun da ke ciki na ruwa (musamman da taro na gishiri a cikin ta), da tsawon lokacin kullum photoperiod, haske tsanani, canji na yanayi. Dukkan wadannan dalilai tsara samar da wasu sel haihuwar. Wasu shuke-shuke nuna spores Dalili na sake yiwuwar tohowarsu, da kuma kira da sporophyte. Shuke-shuke da cewa samar da gametes for haifuwa zuwa jima'i haifuwa (haihuwa cell tare da wani tsari guda da chromosomes a tsakiya), da ake kira da gametophyte. Akwai algae cewa samar da iri na jima'i sel (gametes da spores), sun haka ya kira gametosporofitami. Algae duk wadannan iri na iya bambanta a tsakãninsu biyu morphologically da ilimin. Saboda haka ja alga Porphyry Tener a cikin nau'i na sporophyte kama wani thread, sashe a jere, ana gabatar a cikin substrate, wanda zai iya zama a matsayin calcareous kankara ko bawo na mollusks. Sporophytes wannan nau'in rayuwa a babban zurfin, fi son low haske. Mutane da hannu a samar da jima'i haifuwa sel (gametophytes), rayuwa a cikin nau'i na faranti a cikin sashi na tides a cikin kududdufi ruwa a karkashin zafin lighting. Red algae, kasancewarsa mafi sosai nuna bambancin da kuma kalubale cin hawan keke a cikinsa akwai wani canji na daban-daban siffofin da wanzuwar kwayoyin da wannan nau'in a lokacin rayuwar sake zagayowar - ci gaban heteromorphic.

Ga wanda aka halin yaduwa na gametosporofitov

Gametosporofity hali na da yawa jinsunan kore, launin ruwan kasa da kuma ja algae. canzawar ƙarnõni na faruwa a gare su a cikin ci gaban da iri sel haihuwar: spores da gametes samo asali a daban-daban sau, da kuma saboda canje-canje a cikin muhalli da yanayi. Daidaito tsakanin alamu da cututtuka a phenotype m ga muhalli canje-canje - babban juyin factor bayar da tuki selection form.

Canzawar al'ummomi, a tsire-tsire da kuma a cikin dabbobin: abin da kama da biyu daban-daban mulkokin

Rarrabuwa, raba Rayayye duniya cikin 4 mulkoki, ƙwarai simplifies da ji na kimiyyar halitta a farkon matakai na ta binciken. Duk da haka, a mafi m hanya ya bayyana cewa akwai mutane da yawa matsakaici lokuta a halin yanzu rarrabuwa. Saboda haka, da sãɓãwar da al'ummomi a coelenterates ne musamman mai ban sha'awa hali. A rayuwa ta sake zagayowar daga ƙarnõni na jima'i da kuma sake yiwuwar tohowarsu, da daban-daban bayyanar, ne matuƙa, daban-daban daga juna ta hanyar rayuwa, rayuwa a wurare daban-daban da kuma daban-daban abinci. A metagenesis wani canzawar rayuwa siffofin: polyps da jellyfish. A haɗe zuwa substrate polyps ne masu zama a gida. Domin polyps haifa asexually ta dake tasowa daga iyaye kwayoyin sabon m a kayyade abun da ke ciki rassa mutane suke ciyar da rãyukansu a cikin hanyar polyps. Ikon ake kawota ta mai tacewa da talakawa da ruwa, da na yanzu wanda microscopic barbashi an kawo kwayoyin hidima abinci ga kwayoyin.

Polyps iya shirya wata babbar al'umma. Hakazalika, da sãɓãwar da al'ummomi a coelenterates halitta kwayoyin na dogon lokaci mulkin mallaka siffofin polyps a cikin nau'i na murjani reefs. Lokacin da wani yanayi faruwa cewa ga kowane mutum (canji na zazzabi, lokaci na shekara, da canza undercurrents, Lunar lokaci, hijirarsa, da dai sauransu), polyps toho kananan jellyfish. Jellyfish ne mobile da za a iya sauƙi koma a cikin ruwa, da yara ne a kan hanyar da iko. Girma zuwa da shekaru jima'i shiri, jellyfish jinsunan ci gaba da ci gaban sake zagayowar ta hanyar jima'i haifuwa. Hadu cell tasowa mobile larvae cewa shirya zuwa kasa, an haɗe zuwa substrate, rasa su motsi da kuma girma a cikin wani polyp. Canzawar al'ummomi - shi ta rayuwa sake zagayowar, shigarsu wani irin wanda kokari rufe, ya koma ta farko, amma da wani daban-daban sa na chromosomes, sabili da haka ma tare da sauran fasali.

Mosses kuma haifa jima'i hanya

Canzawar ƙarnõni na faruwa a mafi girma da shuke-shuke, ciki har da mosses. A halayyar alama na sashen na shuka rai sake zagayowar shi ne gaskiya cewa da rinjaye rai tsari ne gametophyte a matsayin kore perennial shuka da ciwon leaf-kamar appendages da kuma rhizoids, wanda mu kiyaye. Canzawar ƙarnõni a mosses samar da wani sporophyte, wanda shine asexual mataki a cikin ci gaban sake zagayowar, wakilta wani kananan akwatin a kan wani zangarniya da spores hade da gametophyte ƙafafunsa, ta hanyar abin da physiological kula da shawarwari. Sporophyte yana da wani gajeren shiryayye rai, ba zai iya daukar tushen a kan nasu. Ta kafe fita bayan maturation da rashes shawarwari.

Me ilmin halitta 1 + 1 = 3

Abin lura da sama, za mu iya cewa da biyu haifuwa hanyoyin da su juyin muhimmanci. canzawar al'ummomi - wani tsari da samar da dole da ãyõyinMu, kuma ba dole ba kin amincewa, bayyana a cikin phenotype, saboda zabin yanayi. Kawai a cikin yanayin da sake yiwuwar tohowarsu, "a kotu" zabin yanayi za a "fallasa" kwatsam maye gurbi, kamar yadda a cikin hali na jima'i, ban da maye gurbi a cikin phenotype nuna alamun biyu iyayentaka jinsunan.

Me ya sa a Juyin halitta, a lõkacin da suka yi magana game da jima'i haifuwa, Naira Miliyan Xari da raka'a biyu ba su daidaita zuwa biyu (1 + 1 ≠ 2)? Saboda a sakamakon hadi da yara mutum na'am da wani sa na genes ba m to wani daga cikin iyaye da tsuntsaye. Mutum ba zai kawo wa masu juna biyu da kuma na uba gene, amma ya ci gaba a kan tushen da bayanai da aka samu daga iyaye. Yana zai zama na uku m, musamman da unrepeatable genotype, don haka masana halitta warware ilimin lissafi misali ne a bit daban-daban. Wannan shi ne abin da na samar da da sãɓãwar da al'ummomi a tsire-tsire da kuma dabbobi masu shayarwa, inda tare da kowane sabon abu akan sake haihuwa a kayyade kayan zama mafi hadaddun, m kuma cikakke.