Tabbatar da dorewar selection: yanayi da kuma muhimmancin da shi a cikin rayuwar mutum

Kamar yadda muka sani, daga ilmin halitta, misali, wata relict shuka, a matsayin ginkgo, ko ko irin Crossopterygii kifi a matsayin coelacanth, akwai kusan babu canje-canje game da shekaru miliyan. Ta yaya za a iya wannan a iya bayyana da zaman lafiyar na nau'in a cikin wani m maye gurbi matakai a cikin yanayi? Amsar wannan tambaya ne da aka ba a la'akari da manufar "tabbatar da dorewar selection" - rukunan cewa an tsara ta mashahuri masana juyin halitta II Schmalhausen.

Ya ce irin selection iya kawai za a lura a akai muhalli da yanayi na a isasshe tsawon lokaci. Wannan shi ne dalilin da ya sa a cikin wannan yanayi, in general, ne na hali da kuma daidai dace don ta mutum kuma da ɗan daban-daban daga wadannan rikidaddu dole halaka. Stabilizer selection aka tabbatar da wani isasshen yawan misalai. Saboda haka, bayan high iskõki da snow game da 136 stunned rabin matattu sparrows da aka samu, a Arewacin Amirka, sun tsira kawai 72 mutane. Daga cikinsu akwai sparrows da ciwon talakawan fuka-fuki, saboda abin da suka yi mafi ƙarfin hali fiye da wanda ya yi da fuka-fuki na mai dogon ko sosai short.

Tabbatar da dorewar selection aiwatar results a cikin phenotypic homogeneity na yawan jama'a. Tare da dogon lokacin da tasiri a kan yanayi na iya ba da alama na immutability jinsunan ko yawan jama'a. Duk da haka, wannan shi ne kawai ya bayyana immutability kuma iya shafi kawai bayyanar. Lokacin da wannan gene pool shigarsu wasu canji (maye gurbi auku).

Tabbatar da dorewar selection halayyar mutumin. An misali ne Down ta ciwo. An sani cewa ga irin hereditary cututtuka sa disturbances a kan kananan 21-22 nau'i-nau'i daga chromosomes. A hali na wani karkacewa a cikin adadin, kuma irin manyan chromosomes, akwai wani halakar hadu qwai. Har ila yau, maras wata-wata abortions sau da yawa sa da mutuwar embryos da chromosomal munanan a tsakiyar.

Tabbatar da dorewar selection ga daruruwan dubban zamanai, shi ne alhakin da kiyayewa jinsunan gagarumin canje-canje da omitting da promutirovavschie form. Ba tare da shi, shi ba zai an kai wasu kwanciyar hankali a yanayi.

Tare da riga tattauna karfafawa, akwai wani mutum selection, wanda ke da amfani a yi la'akari da misalin shuke-shuke. Its ainihi shi ne domin sanin ingancin da zabi shuke-shuke da taimakon wani mutum kimantawa su progenies. A bambanci ga salla selection, ba su gauraya a cikin mutum tsaba zaba shuke-shuke da kuma shuka dabam ga iyalai a wasu yankunan domin samun mai kyau kimanta na zũriyarsu. Tare da wannan dabarar, za ka iya samun wani selection a kan genotype maimakon phenotype.

Sume selection ne mafi dace wa mutum, da kuma za'ayi ba tare da gaba takamaiman aiki. Saboda haka, Darwin ya tabbatar da cewa, misali, a gaban baƙauye tattalin arzikin a cikin biyu shanu, don samar da nama yana yanka shi ne wanda ya bada kasa madara, da kuma a cikin kaji don samar da nama yana bad hens Za a yi amfani da su. Kuma a daya kuma a karo na biyu idan, wani manomi domin ya kula da m dabbobi, yin zabin, kada sanya kanmu da burin bunkasa sabon breeds. Shi ne a cikin wannan da ɗan m form Darwin da kuma nuna sume selection.

By nazarin rayuwar mutanen Australia da kuma Afirka ta Kudu, masana kimiyya suna ƙara tabbata daga cikin daidaitar ka'idodinsu. Sume selection na dogon lokaci don yin wani mutum a taming dabbobin daji. Cewa wannan shi ne halitta na da muhimmanci Tsayawa akan matsayin cewa a cikin aikin noma sabon jinsin dabbobi da kuma shuke-shuke za a iya samu ne kawai ta wajen daukan samfur. Saboda haka, daga cikin rukunan da sume selection na Darwin "haka" da sauran, babu kasa mai muhimmanci, rukunan wucin gadi selection, wanda aka tsara a cikin nau'i na doka, to rinjayi dukan tsari na bunkasa sabuwar shuka iri da kuma dabbobi breeds.