Zabin yanayi: jima'i dimorphism

Jima'i dimorphism - shi ne bambanci a cikin tsarin da namiji da mace kwayoyin da wannan nau'in. An yadu rarraba a tsakanin wakilan iri guda ba dabbobi ko shuke-shuke, da kuma aka bayyana a cikin jiki bayyanar cututtuka irin mutane:

1. Girman. Maza suna bambanta daga mãtã da su size, misali, wakilan halittar dabba mai kafafuwa, mãtan ne ya fi girma.
2. Nunawa. Alal misali, a cikin mutane da shi zai iya zama a yi gyammansu saboda maza.
3. Color. Alal misali, a cikin tsuntsaye - launi gashinsa.
4. Skin. Bayyana, a cikin ƙarin ilimi da kuma sakandare jima'i halaye. Alal misali, a zankayen barewa ko a tsefe zakaru.
5. Hakora. A namiji dabbobi masu shayarwa, kamar dabbar walrus da kuma hauren giwa ne dan kadan ya fi girma fiye mace.

Saboda haka, jima'i dimorphism za a iya kira da mudu na polygamy (ta matakin), da kuma hasken da shi ne aka bayyana a, da girma da bambance-bambance a cikin gudunmawar da namiji da mace ta kula da 'ya'yansu. Wani lokaci PD za a iya bayyana a cikin irin cututtuka, wanda rage viability na masu mallakarsu. Saboda haka, mai haske launin gashi, singing m, ko kaifi wari da wasu tsuntsaye sau da yawa jawo hankalin hankalin yara, wanda shi ne mai hatsari ga rãyukansu. Wannan ne ya sa, mafi m, ba ta halitta zaɓi na yin jima'i.

Jima'i dimorphism ne na dama siffofin:

1. Haihuwa PD - shi ne akai ta jima'i, duka biyu firamare da sakandare, waxanda suke da daban-daban a duka biyu mata da maza da kuma suna da alaka da haifuwa tsari. Wannan hormonal nau'i na jima'i dimorphism, wanda da aiki - don yin shirin duka biyu mata da maza.
2. Gyara na jima'i dimorphism - shi ne wucin gadi da kuma taso saboda mace jima'i canji a sakamakon selection. A wannan yanayin, akwai sabon genes cewa an gwada a namiji DNA.

PD an dauki matsayin da dangantakar da mace namiji halaye, da nufin kafa wani mai karkata zuwa ga juna, wanda halitta da bukatar wani jiki da kuma m adam haifuwa. Saboda haka, shi da nufin haifa a wani ƙarni, tare da a kayyade matakin, akwai halittar da kuma ci gaban nazarin halittu iko mafi m halaye na mutum.

Ya kamata a ce cewa jima'i dimorphism aka bayyana a cikin manyan yawan physiological, ta jiki da kuma halayya da bambance-bambance tsakanin mutane daban-daban jima'i. Saboda haka, ta hanyar da mace addashin selection tabbatar da dorewar, namiji jinsi kuma Halicci da yiwuwar juyin canzawa. Kimiyyar zamani ba bayãnin hukuncin da wanzuwar jinsi bambance-bambance a kowane matakin na ci gaba da kwayoyin.

A dabbobi, PD ne halin da bambance-bambance a cikin tsari na copulatory gabobin ko sakandare jima'i halaye. Ga al'ada ya bambanta yanayi da kuma m jima'i dimorphism. Cikinsa da farko ba ya dogara ne a kan yanayi yanayi.

Jima'i dimorphism mutum bayyana, a wani karfi ci gaban da kwarangwal da tsokoki, kazalika da gashi a cikin maza. A mafi cigaba mace ƙirãza, kwatangwalo nisa da more.

A PD shuke-shuke nuna a cikin bambance-bambance tsakanin tsarin da kuma girman da tushe, foliage yawa, tsarin da furanni da kuma daban-daban a hanyoyi da yawa.

Saboda haka, da fitowan da kuma ci gaban jima'i dimorphism a duk kwayoyin ne ya sa ta rinjayar da na halitta da kuma jima'i selection. A wannan yanayin, ta zamani, ilmin halitta na da yalwa da muhawara a cikin ni'imar da cewa PDP da aka bayyana, ba kawai a cikin tsari da kuma aiki na jima'i gabobin, shi ma yalwaci sakandare, manyan, kuma m daga cututtuka da aikin yin jima'i, wanda koma ga jiki da kuma tsarin da ayyuka. Za mu iya cewa duk wadannan halaye da lãbãri a duk matakan da kungiyar na al'amarin, daga matakin kwayoyin da kuma kawo karshen tare da organismic.