Kev tshwj xeeb hauv qhov yog ua ke nrog cov cai ntawm kev xaiv ntuj tsim thiab tsim los ntawm Charles Robert Darwin.
Speciation yog cov txheej txheem ntawm kev tshwm sim ntawm cov tsiaj txhu tshiab thiab lawv hloov pauv raws sijhawm raws li kev xav ntawm kev xaiv ntuj.
Tib lub sijhawm, yog tias muaj kev sib txuas ntawm caj ces, uas yog, tsis muaj peev xwm tsim cov xeeb ntxwv thaum hla, qhov no yog hu ua interspecies barrier. Lub hauv paus ntawm speciation, raws li lub synthetic theory of evolution (STE), yog hereditary variability, where the lead factor is natural selection.
Muaj ob txoj kev xaiv rau kev tshwj xeeb:
• geographic (alopatric);
• ecological (sympatric).
Piv txwv ntawm ecological speciation yog dav nyob rau hauv xwm. Wb mus saib ib co.
Situation in nature
xyaum biologists nco ntsoov tias piv txwv ntawm ecological speciation tsisib txwm pom ci ntsa iab. Muaj cov pab pawg ntawm cov tib neeg uas tsis sib txuas lossis sib txuas me me, tsis hais txog keeb kwm yav dhau los. Piv txwv li, dub grouse los yog capercaillie yog hom sib txawv kiag li, tab sis lawv muaj peev xwm genetic interbreed. Cov piv txwv hauv qab no yog: aub, hma thiab jackal; feem ntau ntawm cov mos lwj. Hauv speciation (geographical, ecological), qhov xwm txheej tseem ceeb yog qhov tshwm sim ntawm kev cais tawm ntawm biomorphs, txawm tias lawv nyob hauv tib cheeb tsam.
Ecological speciation
Lub tswv yim no yog hais txog cov txheej txheem ntawm kev tsim cov hom tshiab hauv ib cheeb tsam sib koom. Nws yog ecological yam ntxwv ntawm txoj kev loj hlob uas tsis pub lawv mus interbreed, vim hais tias cov pejxeem nyob txawv ecological niches. Yuav tsum to taub li cas? Nyob rau hauv cov xwm, nyob rau hauv txawv variants, piv txwv ntawm ecological speciation tshwm sim nyob rau hauv kev sib piv ntawm nroog thiab nyob deb nroog swifts. Yog lawv nyob hauv tib lub cell ces lawv yuav tsis muaj xeeb ntxwv. Lawv muaj cov yam ntxwv morphological thiab physiological sib txawv.
Kev txhim kho ntawm qhov zoo
Qhov piv txwv pom tseeb tshaj plaws ntawm ecological speciation yog tsim los ntawm cov cim ntxiv ntawm tib hom, tab sis nyob rau thaj tsam sib txawv.
Piv txwv li, muaj ntau hom buttercups thiab tradescantia uas tau yoog kom loj hlob nyob rau hauv ntau yam kev mob - teb, meadows thiab raws ntug dej, nyob rau hauv txawv natural habitats. Polyploids kuj tau pom, uas tus naj npawb ntawm chromosomes txawv. Nyob rau hauv cov tsiaj, convergence tshwm sim - lub convergence ntawm cov paib, thiab zoo xws li cov yam ntxwv ntawm lub cev.
Cov piv txwv ntawm ecological speciation yog pom nyob rau hauv cov xwm kuj nyob rau hauv cov qauv ntawm lub cev duab nyob rau hauv cov ntses: cartilaginous sharks, ichthyosaurs (tuag) thiab ntses taub ntswg ntev. Qhov no yog qhov tshwm sim ntawm kev sib koom ua ke ntawm cov tsiaj txhu sib txawv.
Kawg xaus
Nyob hauv qhov xwm txheej, qhov kawg ntawm speciation yog kev sib cais ntawm kev yug me nyuam thaum cov teeb meem uas twb muaj lawm raug tshem tawm, tsis hais thaj chaw lossis ib puag ncig. Txawm hais tias cov tiam tshiab uas tshwm sim yuav tshwm sim, ploj mus, lossis faib ua pawg me me yog nyob ntawm qhov kev sib raug zoo ntawm kev sib raug zoo. Piv txwv ntawm ecological speciation qhia tias biodiversity nyob rau hauv cov xwm yog tsim nyog rau evolutionary txoj kev loj hlob.
