Nyama: kufotokoza mwachidule

Pakali pano, nyama amaonedwa kukhala mmodzi wa magulu zotsogola. gulu amakhala ndi nambala ya zinthu zofunika kwambiri. Malinga ndi akuti maphunziro padziko lonse lapansi lero pali anthu oposa zikwi zisanu m'kalasimo. Ngakhale Dziwani kuti chithunzi ichi ndiyopenekela kwambiri, chifukwa asayansi ndipo akufunafuna mitundu yatsopano tsiku.

Nyama ndi kugawa awo

Nyama amaonedwa kukhala oimira wapadera ndithu zomera. Iwo amafalitsidwa padziko lonse.

Oimira kalasi angapezeke pafupifupi malo aakulu a Dziko Lapansi. nyama zimenezi zolengedwa wokongola yotentha chipululu nyengo zigawo ya kumapiri. Inu mukhoza kuwona izo mu zigawo kumalo ozizira ndi Nkhalango otentha. Iwo ali otchuka ngakhale m'malo m'madzi.

Mwina malo okha amene si litadzala ndi nyama ali mkati m'dera la Antarctica ndi gawo zozama za m'nyanja dziko.

N'zochititsa chidwi, dera kufalitsa monotremes nyama (mwachitsanzo, platypus) kuonekeratu okha m'madera a New Guinea ndi Australia. Marsupials oimira anagawira pa zilumba za Oceania, komanso Australia ndi ku dera la ku America. Ndipotu ina chidwi n'chakuti pa dziko la Australia anali anthu nyama ochepa placental isanafike atsamunda choyamba.

Nyama: mbali yaikulu ya kalasi

Monga tanenera kale, izi gulu la nyama amagwiritsa ntchito mikhalidwe yapadera, kusonyeza mkulu mlingo wa bungwe:

• Pafupifupi viviparous nyama.
• Akazi kosungiramo mkaka ana awo opangidwa ku zopangitsa mndandanda (by njira, chifukwa chakuti ichi nyama dzina lawo).
• Maphunziro oimira ndi khungu yeniyeni, akuchita sebaceous ndi thukuta zopangitsa.
• Pakuti otchedwa homeotherms mmene zolengedwa zoyamwitsa, kapena magazi ofunda - kutentha thupi lawo sikudalira zikhalidwe ndi yozungulira kutentha.
• Mbali kwambiri za gulu la nyama ndi ubongo bwino anayamba, makamaka gawo lotsiriza la izo. Apa ndi pakati mwa umene oimira amakhala makhalidwe zovuta.
• Mu nyama anapanga auricle, lakunja khutu ngalande, komanso onse atatu a ossicles Makutu, zomwe, poyamba, ndi kusinthidwa mandible.
• Anthu a kalasi yodziwika ndi zapamwamba zinayi chambered mtima ndi kumanzere kung'ambika Chipilala, yomwe kulekana kwa magazi pa venous ndi wolumikizira (mwachitsanzo, mu zokwawa ndi venous magazi wolumikizira ali osokonezeka mu mtima).
• Chinthu chapadera tinganene kuti ndi kapangidwe alveolar a m'mapapo.
• Komanso, pali kusiyana mu kapangidwe ka maselo magazi - maselo ofiira a nyama zimenezi mulibe mtima, ndi pigment kupuma.
• Nyama ndi vertebrae zisanu ndi ziwiri mu dera khomo lachiberekero.
• Pakuti m'gulu limeneli yodziwika ndi mtundu wa mano (pamaso pa incisors, canines, molars). Pankhaniyi kudzera mizu mano kumizidwa mu nsagwada fupa.

Magwero a nyama

Asayansi amakhulupirira kuti makolo a nyama amakono anali zokwawa kuti anaonekera mu Paleozoic. Nyama zimenezi nachobe ena kufanana ndi achule ndi, makamaka, pamaso pa zopangitsa khungu ndipo mwina wachiphamaso occipital condyle.

Makamaka achibale a mitundu ano nyama ngati amaonedwa. Oimira gulu limeneli yodziwika ndi kukhalapo kwa mano osiyana (molars, incisors ndi canines). Chapamwamba ndipo m'munsi nsagwada linagwirizana fupa wapadera umene kusanduka mu ossicles zolengedwa zoyamwitsa Makutu. Koma akuluakulu a zinatha nyama ngati mu Upper Triassic.

Kale mu nthawi Jurassic, panali kulekana kwa mitundu moyo zobala kwa anthu amene anaika mazira.

Ndipotu bwino zopanga chiphunzitso cha chiyambi cha nyama n'zosatheka, chifukwa lero, zokwiriridwa asayansi ndi kafukufuku mwachangu ku dera limeneli.