Ndevapi mhuka uye sei akasiyana nedzimwe mhuka?

Ndivanaani mhuka? kirasi iyi inosanganisira mhuka zvemberi vari zvachose yakasiyana nemhuka: a nzou hombe uye duku mbeva-vole, hachingafambipo Bere negwayana munyoro. Yavanogara nhetembo yose: panyika, zviri mugungwa (Dolphins uye hove huru), mhepo (zviremwaremwa). Asi chii chinosiyanisa kubva nedzimwe mhuka? Warm ropa? Chete Pakanzi tinoberekwa uye neshiri. Kugona kubereka kurarama vaduku? Eya, chokutanga, kwete mhuka dzose dziri viviparous. Vamwe vavo mazai avo, sezvo, Somuenzaniso, platypus, apo vamwe vechiduku pakuzvarwa vakawanda vakaita saibva embryo uye kuti "ripen" rinokosha mazai chenguva duku-homwe nedumbu raamai akaita kangaruru. Uye chechipiri, varipo viviparous uye dzimwe zvinokambaira, hove uye kunyange nezvipembenene. Panyaya kuti mhuka pane vakasiyana hove, mhinduro iri nyore: kuvapo chiedza. mhuka dzose kufema mhepo. Naizvozvo, kuti rehove haafaniri kusimuka pemvura kufema, kusiyana akafanana naye chitarisiko Dolphin, izvo zvinogona nyore kunyura pasina okisijeni inopa upenyu. Asi, zvakare, mapapu vane chinyakare amphibians zhinji, neshiri dzose.

Pakati hombe kusiyana nemhuka parameters maviri chete vangazivikanwa dzaanofanira ari mhuka. Ndicho pamberi bvudzi uye kudya mhuru mukaka. vakadzi Zvose izvi mapoka mhuka dziri mutumbi mammary omumuviri, izvo azadzwa inotonhorera zvokunwa pashure yokusununguka. pfuma iyi uye akapa zita mhuka dzose. Pakati pezvimwe zvinhu zvaizobatsira mhuka, unogona kuwedzera pamberi rezasi shaya, zvinosanganisira rimwe pfupa, uye diaphragm kuti Anopatsanura mapapu uye mwoyo kubva zvomudumbu turakiti.

Asi chinonyanya chinokosha kuziva kuti mhuka ndiyo uropi yavo kusimba dzakabudirira uye kusanduka hurongwa maitiro. Izvi zvinoreva kuti vanhu vaviri chete kwemarudzi, kamwe chete muupenyu kunogona kuita zvakasiyana. Vanokwanisa kushandisa ruzivo rwavo, kuchengeta uye kufunga. Hazvishamisi kuti boka mhuka akazviratidza maonero Homo sapiens - Homo sapiens. Zvakanaka, asi iye Pasi inogarwa inenge 5000 marudzi nedzimwe mhuka, iyo dzikarongwa Systematics 1,100 genera, 140 mhuri uye 18 zvirevo uye 3 mhuri.

No dzinonakidza zvishoma muri mapazi mhuka. Nokuti zvose zvavo kusiyana pachena (zvikara zvipikiri, minwe netsoko dzevanhu, akaparadzana), vose vanoguma aine horny manda - munhu nzara. In mhuka kurarama mvura, azvaiitwa achaita atrophy. Nyaya iyi iri kuchinja kwezvakatipoteredza mamiriro vakabatsira kuti mhuka vakaparadzira zvose pamusoro nyika uye ukatora zvose zvoupenyu niche - panyika, mudenga, mugungwa, pasi pevhu. Nokuda kukwanisa kuramba muviri tembiricha anofadza-ropa rechiJudha chairo, vanogona kurarama kweArctic (polar samapere) uye dzinopisa (inosvetuka, ngamera) magwenga.

The mubvunzo unomuka: apo paiva mhuka vokutanga? Hapana mubvunzo kuti mukuru mhuka akawana makore dinosaurs. Ipapo vakanga kunyanya duku kwazvo, uye akaratidza zviratidzo "mhuka-kufanana nezvinokambaira." Sezvo masayendisiti kushanda zvisaririra, vava marangwanda chete, zvakaoma kuona pane padanho iri mhuka idzi akazviratidza shinda uye kukwanisa kudyisa mhuru mukaka. Kana tatanga kubva chokuratidza edinokostnoy mandible, tinogona zvakachengeteka kutaura kuti kunyange mamiriyoni 215 apfuura mune South Africa, Europe uye China yaigarwa chiduku (masendimita 15), mhuka chakatodzana shrew ano.