Haduwa - shi ne, ba wuya

Ga waɗanda ba su sani ba abin da haduwa da ilmin halitta, ya kamata a bayyana cewa manufar zo mana daga Latin kuma yana nufin "haduwa." Ya kamata a lura cewa wannan definition aka yi amfani ba kawai a cikin ilmin halitta, amma kuma a cikin harsuna, sadarwa, har ma a fannin kimiyyar siyasa. Wannan shi ne dalilin da ya sa shi ya kamata a fahimci cewa haduwa - akwai ãyã daga wani kama a kwayoyin da suke da jũna a cikin yanayi, wanda ya tashi a cikin mahallin juyin halitta. A sakamakon wannan tsari, suna da wani yawan irin halayen (msl, bayyanar, tsarin jikinsu).

Mutane da yawa san cewa hanyar haduwa fito, misali, streamlined shark, da dabbobin ruwa, yawo membranes marsupials squirrels da kuma yawo squirrels. Idan muka magana game da juyin nau'i na kungiyoyin na rayayyun kwayoyin halitta, shi ne kasaftawa haduwa da kuma bambanta rarrabuwar, kazalika da parallelism.

A irreversibility na tsarin juyin halitta

A ci gaba da kowane kwayoyin da aka wuce wasu matakai a su ci gaba, da kuma wannan ya shafi cikakken duk tsarin aka gyara. Kuma idan haduwa - shi ne mai "kama", ya kamata ka yi la'akari da zurfafawa da sauran matsalolin.

1. bambanta rarrabuwar - bambancin da suke da halaye da cewa wanzu a cikin wani musamman jinsunan. Wannan nazarin halittu aiwatar manyan zuwa fitowan da sabon kungiyoyin da kuma mutane. A bambanta rarrabuwar ne mafi pronounced, da girma da bambanci zama musamman irin, tare da sakamakon cewa jiki fara sãɓã wa jũna ba kawai a cikin bayyanar amma kuma a cikin ciki tsari, a kan yanayi da kuma halaye na sarari na da zabi ga zama. Kuma daya yankin iya kawai zaži waɗanda suka iya tsira a cikin yanayi. Saboda gaskiya cewa key manufar juyin halitta ne zabin yanayi, kawai fittest tsira iri, kuma mafi rauni - mutu.

2. haduwa - shi ne, a sama da dukan, wani sabon abu m bambanta rarrabuwar. A wannan yanayin, da daban-daban kwayoyin fara saya kama siffofin. Sau da yawa wannan shi ne saboda wannan mazauninsu, ta asali yanayi da kuma halaye. Ya kamata a lura da cewa sabon abu na haduwa ne ya fi kowa a cikin dabba duniya, inda, misali, tsuntsaye ba zai iya rayuwa ba tare da fuka-fuki, kifi ya zama streamlined siffar da sauransu.

3. Parallelism - fassara daga Girkanci harshe, wannan ra'ayi yana nufin "mataki na gaba". Wannan ci gaba a cikin mahallin na juyin kama kungiyoyin da suke da genetically kusa, amma da saye da kamance tsakanin wadannan wakilan ba ya dogara ne a kan juna. Kusan ko da yaushe, wadannan siffofin suna gada daga kakanni. Ganin cewa haduwa - shi ne misãlai cewa ana hankali kunno kai daga wani dogara, concurrency aka ƙaddara kai tsaye ta hanyar da tarihi aiwatar (musamman, muna magana ne game da phylogeny).

Me yasa akwai haduwa sabon abu

A lokacin da la'akari da ainihin matsalolin a cikin mahallin juyin halitta an ce cewa haduwa - wani m sabon abu, wanda shi ne muhimmi a cikin babban wakilan da dabba duniya. Babu shakka, da bambanta rarrabuwar kuma parallelism ne sau da yawa samu a yanayi. Amma da bukatar haduwa ba za a iya hana, saboda Sanadin wannan kamance ba m da gaban zumunta da wani sa na bayyanar cututtuka da suka ci gaba a cikin tsarin juyin halitta, to daya ko wani irin rayayyun kwayoyin halitta su tsira da zama karfi.

Saboda haka, babban dalilin ne haduwa da kai tsaye kama da muhalli maharibai suka zauna wadanda ko wasu wakilan da dabba duniya. Idan ka duba cikin rare misalai na convergent kamance, za mu iya fahimtar dalilin da ya sa wasu iri wakilan rayayyun kwayoyin halitta da wani musamman siffar, bayyanar, da kuma wasu salon dalilai.