Cov taxon tsawg tshaj plaws (ib pawg hauv biology) hu ua hom. Ib hom yog ib pawg ntawm cov tib neeg uas muaj cov yam ntxwv morphological zoo sib xws, sib cuam tshuam ywj pheej thiab tib lub sijhawm muab cov xeeb ntxwv zoo. Muaj lwm yam, ntau dua taxa. Ib pawg ntawm cov tsiaj sib raug zoo, piv txwv li, tsim ib lub genus, thiab los ntawm cov genera ze ze ib tsev neeg tau txais, thiab lwm yam. Tab sis hnub no peb yuav tham txog qhov tsawg tshaj plaws taxonomic qeb, uas yog, hom. Dab tsi yog hom, qhov no taxon tsim li cas, thiab cov txheej txheem ntawm speciation muaj nyob rau hauv dab tsi? Yog li cia peb pib.
Speciation in nature
Speciation yog txheej txheem ntawm kev tsim cov hom tshiab thiab lawv hloov. Nws muaj xws li ib tug barrier ntawm interspecies compatibility. Dab tsi yog?
Ntawm no yog hom tsiaj, thaum hla, tsis muaj peev xwm tsim tau cov xeeb ntxwv. Raws li txoj kev xav ntawm evolution, speciation nyob ntawm kev hloov pauv hloov pauv. Niaj hnub no nyob rau hauv biology muaj ob hom speciation - geographical thiab ecological. Wb tham txog txhua tus kom ntxaws ntxiv.
Geographic speciation
Geographical, lossis, raws li nws tseem hu ua, allopatric speciation, yog qhov tsim ntawm hom tshiab hauv kev sib cais spatial. Yooj yim hais, tsim ib hom los ntawm cov pej xeem nyob hauv thaj chaw sib txawv. Txij li cov pej xeem sib cais tau ntev, kev sib cais ntawm caj ces tshwm sim ntawm lawv.
Nws tseem nyob txawm tias cov pej xeem tsis raug cais lawm. Muaj ntau qhov piv txwv ntawm thaj chaw speciation tuaj yeem raug suav hais tias. Cia peb coj lub Tsib Hlis Lily ntawm lub hav ua piv txwv. Nws muaj tsib thaj chaw ywj pheej ib zaug, uas thaum xub thawj tau suav tias yog ib qho. Nws yog ib qho tseem ceeb uas lawv txhua tus nyob ntawm qhov deb ntawm ib leeg. Cov haiv neeg tau tshwm sim nyob rau hauv txhua thaj chaw, uas ua rau tsim cov nroj tsuag ywj pheej. Tsis tas li ntawd, siv qhov piv txwv ntawm kev tsiv teb tsaws chaw, xav txog kev hloov pauv ntawm lub tit zoo. Cov tsiaj no, uas nyob hauv Europe, pib nyob ze rau sab hnub tuaj. Rau qhov no muaj txoj kev sab qaum teb thiab sab qab teb. Ze rau sab qab teb, xws li cov subspecies xws li Bukhara thiab cov mis me me tau tsim, ze rau sab qaum teb - me thiab loj. Tom kawg tsis tsim hybrids.
Yog li ntawd tau tshwm sim los ntawm qhov kev sib hais haum no, muaj kev cuam tshuam kev loj hlob ntawm lawv. Cia peb xav txog ib qho piv txwv ntxiv. Ib hom qub ntawm Australian parrot muaj nyob hauv South Australia. Nws yog ib nqi sau cia hais tias qhov no yog ib tug heev humid cheeb tsam. Nrog rau qhov pib ntawm drought, lub cheeb tsam tau hloov, raws li ib tug tshwm sim ntawm cov cheeb tsam tau muab faib ua ob ntu:sab hnub tuaj thiab sab hnub poob. Lawm, rau ib lub sij hawm ntev, ntau hom parrots tau tsim rau txhua tus ntawm lawv. Tom qab ib tug ntev lub sij hawm, lub qub cheeb tsam tau xyaum rov qab. Kev nyab xeeb dua qub tau zoo ib yam, tab sis ib zaug ib hom tsis tuaj yeem sib txuas ntxiv lawm, vim muaj kev sib cais ntawm caj ces. Yog li, allopatric speciation yog txuam nrog kev sib cais. Raws li qhov tshwm sim, hom tshiab ywj pheej raug tsim.
Ecological pathway of speciation
Muaj lwm txoj hauv kev ntxiv rau thaj chaw. Qhov no yog ecological speciation. Nws kuj muaj lub npe thib ob - sympatric. Txoj kev no yog dab tsi? Ecological speciation yog qhov tsim ntawm hom tshiab raws li qhov tshwm sim ntawm kev sib txawv ntawm cov tib neeg hauv cov cheeb tsam sib txawv. Ntawd yog, thaum pib, cov tsiaj nyob hauv ib cheeb tsam, thiab tom qab ntawd, vim muaj kev sib tw ntxiv, nws nyob hauv lwm thaj chaw. Piv txwv li, koj tuaj yeem soj ntsuam qhov xwm txheej hauv qab no. Loj rattle blooms tag nrho lub caij ntuj sov. Tab sis yog hais tias txhua txhua xyoo nyob rau hauv nruab nrab ntawm lub caij ntuj sov nyom yog mowed nyob rau hauv lub cheeb tsam no, ces cov nroj tsuag yuav tsis muaj peev xwm tsim noob. Vim li no, cov noob uas tau muab ua ntej lossis tom qab txiav nyom tau khaws cia.
Yog li, ob hom hauv tib lub tiaj nyom tsis tuaj yeem sib txuas. Ecological speciation tuaj yeem lees paub los ntawm qhov muaj feem cuam tshuam ntawm hom kab nyob ib sab. Qee lub sij hawm cov cheeb tsam no txawm coincide.
Speciation and its role
Txoj kev speciation tau kawm ntev, tab sis kev kawm nyuaj heev. Qhov no yog vim lub sijhawm ntawm cov txheej txheem speciation. Ecological thiab thaj chaw tshwj xeeb txawv ntawm ib leeg, txawm li cas los xij, txhua tus ntawm lawv muaj qee qhov tseem ceeb hauv lub neej ntawm xwm. Lawv lub luag haujlwm tseem ceeb yog tsim cov hom tshiab.
