mz;ikapy; Ner;rh; (Nature) vd;w rQ;rpifapy; ntspte;j gbkj;ij tpLgl;l njhlh;G vd;W rpj;jhpg;gjw;fhf lhh;tpd; rpe;jid kPbahf;fs; Gjpa gpur;rhuj;ij njhlq;fpAs;sd. ,e;j Nfs;tpf;Fwpa kPd; gbkk; Mh;bf; fdlh gpuNjrj;jpy; ePy; Rgpd; (Neil H. Shubin) kw;Wk; vl;th;l; nl];yh; (Edward B. Daeschler) Mfpa ,uz;L Ma;thsh;fshy; 2004k; Mz;L fz;Lgpbf;fg;gl;lJ. bf;lhypf; Nuhrpah vd;w tpQ;Qhd ngahplg;gl;l ,e;j gbkk; Rkhh; 385 kpy;ypad; Mz;Lfs; goiktha;e;jJ. ePhpypUe;J epyj;jpw;F khw;wkilAk; NghJ mt;tplj;jpy; tpLgl;l njhlh;Gf;F jFe;j Ntl;ghsiu Njbf; nfhz;bUe;j ghpzhkthjpfs; ,e;j gbkj;ij mjd; njsptw;w jd;ikfis kiwj;J> ,ij mth;fs; ep&gpf;f jpzwpf;nfhz;bUe;j ,lj;jpy; nghUj;jp tpLgl;l njhlh;G (missing link) vd;W fhl;l Kaw;rpf;fpd;wdh;.

,Ug;gpDk; ePhpypUe;J epyj;jpw;F khw;wkiljy; vd;gJ fw;gid fijahFk;. Vnddpy; epyj;jpy; thOk; caphpdq;fSf;Fk; kPd;fSf;Fk; ,ilapy; fhzg;gLk; cly;hPjpahd ngUk; tpj;jpahrq;fis ghpzhk tsh;r;rp Nfhl;ghl;bd; fw;gid njhopw;ghLfis nfhz;L xU NghJk; ep&gpf;f KbahJ. tpQ;Qhdj;jpw;Fk; vjpuhf ,Ue;j NghjpYk;> ghpzhk tsh;r;rp Nfhl;ghl;bd; kPJ mth;fs; nfhz;Ls;s fz;%bj;jdkhd Mjutpd; fhuzkhfTk; ,iwtid kWf;f Ntz;Lk; vd;gjw;fhfTk;> ,e;j ,lj;jpy; bf;lhypf; Nuhrpah gbkj;ij gpioahd juTfis nfhz;L nghUj;j Kw;gLfpd;wdh;.

lhh;tpd; rhh;G kPbahf;fs; gpur;rhuk; nra;Ak; bf;lhypf; Nuhrpah gbkj;jpy; mth;fs; Ntz;Lnkd;Nw kiwj;jtw;iw fPNo jUfpNwhk;:

bf;lhypf; Nuhrpah : ghpzhk tsh;r;rpf;F rhd;whf nfhs;s KbahJ

bf;lhypf; Nuhrpah rk;ge;jkhd ed;F ghJfhf;fg;gl;l %d;W gbkq;fs; fhzg;gLfpd;wd. %d;W kPl;lh; ePsKs;s rpy gbkq;fs; Nkhrapf; gz;Gfis (mosaic characteristics) nfhz;Ls;sd. (nkhrapf; caph; mikg;Gfs; gy;NtW tpj;jpahrkhd caphpdq;fspd; gz;Gfis nfhz;bUf;Fk;). kPd;fspy; cs;sij Nghd;W mjw;F nrjpy; kw;Wk; ];Nfy;fs; cs;sd. epyj;jpy; thOk; caphpdq;fis Nghd;w jl;ilahd jiy> cWjpahd vYk;G kw;Wk; efUk; fOj;J fhzg;gLfpd;wd. ,e;j caphpdj;jpd; ngah; ,Da;l; (Inuit language) vd;w nkhopapypUe;J ngwg;gl;Ls;sJ. me;j nkhopapy; ,Df;bLl; (Inuktitut) vd;gjd; fUj;J nghpa> ed;dPPh; kPd; vd;gjhFk;. mjw;F nrjpypy; Ks; vd;w fUj;Jk; cz;L. ghpzhkthjpfs; ,e;j nkhrhapf; gz;Gfis kiwj;J mth;fSf;F Vw;wthW tbtikj;J kPdpypUe;J epy caphpdq;fs; Njhd;wpd vd;w mth;fsJ fw;gid fijf;F Njitahd tpLgl;l njhlh;G vd;gij ep&gpf;f Kw;gLfpd;wd.

nkhrhapd; caphpdq;fs; vd;gJ ghpzhk tsh;r;rp Nfhl;ghl;bw;F Njitahd tpLgl;l njhlh;ig (missing link) tpl kpf njhiytpy; cs;sJ. jw;NghJ mT];jpNuypahtpy; tho;e;JtUk; gpsbg]; vd;w xU tif kpUfk; Ch;td> ePh; tho; caphpdk; kw;Wk; gwitfspd; gz;Gfis Vf fhyj;jpy; xNu Neuj;jpy; nfhz;Ls;sJ. ,Ug;gpDk; mij ghpzhk tsh;r;rp Nfhl;ghl;bw;F rhd;whf nfhs;s KbahJ. ghpzhkthjpfs; mth;fsJ $w;Wfis nka;gpf;f nkhrhapf; gz;Gfis nfhz;l caphpdq;fis Njl Njitapy;iy. mjw;F gjpyhf mtw;Wf;F ,ilg;gl;l njhlh;Gifs (intermediate forms) jhd; Njb fz;Lgpbf;f Ntz;Lk;. mjhtJ ghjp tsh;r;rpaile;j Mdhy; ed;F nray;gl Kbahj cWg;Gfis nfhz;l caphpdq;fis jhd; fz;Lgpbj;J fhl;l Ntz;Lk;. ,Ug;gpDk; nkhrhapf; caphpdq;fspd; xt;nthU cWg;Gk; ed;F epiwthf nray;glf;$baJk; vt;tpj FiwghLfSk; mw;wJkhFk;. mtw;wpd; clypy; ghjp tsh;r;rpaile;j ve;j cWg;Gk; ,y;iy. mitfs; NtW caphpdq;fspypUe;J ghpzhk tsh;r;rpaile;jJ vd;gij fhl;lf;$ba ve;j gbk njhlh;GfSk; (intermediate forms) ,y;iy.

ghpzhk tsh;r;rp Nfhl;ghL xOq;fpy;yhj ,izg;gpy; ek;gpf;if itj;Js;sJ. NtW tifapy; nrhy;tnjd;why; mitfs; jw;nrayhf ,ize;jd vd;gjhFk;. ,e;j thjj;jpd; mbg;gilapy; ghh;f;Fk; NghJ> cyfpYs;s gy Nfhb caphpdq;fs; jw;nrayhf ,ize;jjd; tpisthf> mit cU khw;wkile;J> tpj;jpahrkhd mikg;ig nfhz;l> ,ilg;gl;l epiyfisfs; (intermediate forms) vd;W mth;fs; miof;fpd;w gy;yhapuf;fzf;fhd gbkq;fs; ,Ue;jpUf;f Ntz;Lk;. NtW tifapy; nrhy;tnjd;why;> ,aw;ifapd; tpisahl;L; vd;W th;zpf;f $ba ,il epiy caphpdq;fspd; (mjhtJ ,uz;L caphpdq;fSf;F ,ilg;gl;l xU fyg;G caphpdk;) gbkq;fs; epiwe;J fhzg;gl Ntz;Lk;. ,Ug;gpDk; mt;thW epfotpy;iy. caphpdq;fs; Njhd;wpaNghJ mit jpBnudTk; mtw;wpd; jdpj;Jtkhd gz;Gfs; ed;F tsh;r;rpaile;j epiyapy;> vt;tpj FiwghLfSkpd;wp Njhd;wpd. Xf;];Nghh;l; gy;fiyfof mUq;fhl;rpafj;jpYs;s caphpay; Nrfhpg;G jiyth;> Nlhk; nfk;g; (Tom Kemp)> 1999k; Mz;L ntspapl; mtuJ Fossils and Evolution vd;w Gj;jfj;jpy;> ,t;thW $Wfpwhh;:

gbk jfty;fspy; Kjd;Kiwahf Gjpa caphpdq;fs; gbAk; NghJ mjd; kpfTk; jdpj;Jtkhd gz;Gfs; vy;yh epiyfspYk; Gjpjhf gjptJld;> eilKiwapy; mjpy; vkf;F njhpe;j ve;j xU %jhijah; FOTk; njhlh;Ggltpy;iy. (Tom Kemp, Fossils and Evolution, Oxford University, Oxford University Press, 1999, p. 246)

nghJthd gz;Gfis kiwj;j ghpzhkthjpfs;

gbk jfty;fs; jq;fsJ fl;Lf;fijia cz;ikgLj;JfpwJ vd;w rpe;jidia ghpzhkthjpfs; rpj;jhpf;f Kaw;rpf;fpd;wdh;. gbkq;fspYs;s jfty;fs; mth;fSf;F cjthj NghjpYk; ghpzhk tsh;r;rp Nfhl;ghl;il ep&gpg;jw;fhd eph;ge;jk; fhuzkhf ,il epiy (intermediate forms) vd;w xU epiy cUthf;fg;gl;lJ. mth;fspd; fl;Lf;fijapy; xt;thU caphpdj;ijAk; kw;w caphpdj;NjhL ,izf;Fk; gbkq;fs; lhh;tpd; fhyk; KjNy ,d;W tiu fhzg;glhik mth;fis ngUk; ftiy nfhs;s nra;fpwJ. lhh;tpd; fhyk; Kjy; Ma;thsh;fs; Nkw;nfhz;l Kaw;rpfs; midj;Jk; mth;fsJ fl;Lf;fijia ep&gpf;f jtwptpl;lJ. mJ ghpzhk tsh;r;rp Nfhl;ghl;by; ngUk; gpd;dilit fhl;LtJld; caphpdq;fSf;F ,ilapy; ,il epiy (intermediate forms) vd;w epiy ,y;yNt ,y;iy vd;gij cWjpg;gLj;JfpwJ.

Rethinking Anthropology vd;w Gj;jfj;jpy; Mrphpauhd yPr; (E. R. Leach)> Nature rQ;rpiff;F vOjpa fl;Liuapy; ,t;thW Fwpg;gpLfpwhh;:

gbk jfty;fspy; tpLgl;l njhlh;G (missing link) rk;ge;jkhd jfty;fs; fhzg;glhik lhh;tpid ftiy milar;nra;jJ. mtuJ Mjuthsh;fs; mtw;iw fz;Lgpbg;ghh;fs; vd;W mth; cWjpahd ek;gpdhh;. ,Ug;gpDk; mth;fshy; ,d;W tiu fz;Lgpbf;f Kbatpy;iy> ,e;epiy NkYk; njhlUk; vd;W epidf;fpNwd;. (E. R. Leach; Nature, 293: 19, 1981)

Nuhkh; (A. S. Romer)> mtUila fhyj;jpy; kpf gpugy;akhd Ma;thsuhf fUjg;gl;lhh;. mth; ,t;thW Fwpg;gpLfpwhh;:

kpfTk; mj;jpatrpakhd ,lj;jpy; (caphpdq;fSf;F ,ilapy; khw;wkilAk; Gs;spapy;) njhlh;Gfs; (Links) tpLgLtJ> vjph;fhyj;jpYk; njhlh;Gfs; njhlh;e;J tpLgl;Nl ,Uf;Fk;. (A. S. Romer, in Genetics, Paleontology and Evolution, 1963, p. 114)

xf;yN`hkh gy;fiyfofj;jpd; tpQ;Qhd kw;Wk; Gtpapay; tuyhw;W Nguhrphpah;. Nltpl; fpl;]; (David B. Kitts)> ghpzhk tsh;r;rpf;F Njitahd ,ilepiyfs; fz;Lgpbf;f jtwpaikia xg;Gf;nfhs;fpwhh;.

ghpzhk tsh;r;rpf;F ,ilepiyfs; Njit mdhy; mtw;iw mfo;thuha;r;rpfs; jutpy;iy. (David B. Kitts, "Paleontology and Evolutionary Theory," Evolution, Vol. 28, September 1974, p. 467)

gbkq;fs; Ma;T nra;ag;gl;l NghJ mit midj;Jk; ,iwtdhy; gilf;fg;gl;ljw;fhd rhd;Wfis nfhz;bf;fpd;wd. mj;jifa jfty;fs; midj;Jk; caphpdq;fs; jpBnud Njhd;wp vt;tpj khw;wKk; ,d;wp xU ngUk; fhyk; tho;e;Js;sij fhl;Lfpd;wd. mNkhpf;f Ma;thsh; ntrd; (R. Wesson)> 1991k; Mz;L ntspapl;l mtuJ beyond Natural Selection. vd;w Gj;jfj;jpy; ghpzhkj;ij Mjhpf;Fk; gbkq;fis Ma;T nra;J mjd; cz;ik epiyia njspthf tpsf;fpAs;shh;. gbkq;fSf;F ,ilapy; fhzg;gLk; ,ilntsp cz;ikahdit vd;W Fwpg;gpLfpwhh;. ghpzhkj;jpd; xt;nthU fpisapYk; mjd; ghpzhkk; njhlh;ghd Mjhuq;fis ep&gpf;f jtwpaik kpf njspthdJ vd;W ntrd; NkYk; Fwpg;gpLfpwhh;.

caphpdq;fs; nghJthf xU ngUk; fhyg;gFjp vt;tpj khw;wKk; ,d;wp ,Ue;Js;sd. caphpdq;fSk; (Species) caphpd FLk;gKk; (genera) NtnwhU Gjpa caphpdkhfNth my;yJ caphpd FLk;gkhfNth ghpzhkk; milatpy;iy> Mdhy; mit NtW xU caphpdj;jhy; ,lkhw;wg;gl;Ls;sJ. ghpzhk khw;wq;fSf;F nghJthf jil Vw;gl;Ls;sJ. (R. Wesson, Beyond Natural Selection, MIT Press, Cambridge, MA, 1991, p. 45)

,d;Wtiu Rkhh; 2>50>000 gbkq;fs; Nrfhpf;fg;gl;Ls;sd. mtw;wpy; xd;wpy; $l ,ilepiy rk;ge;jkhf ve;j jlaKk; ,y;iy. ghpzhkthjpfs; klikiapd; fhuzkhfTk;> ,iwtid kWf;f Ntz;Lk; vd;gjw;fhfTk;> tpQ;Qhdj;jpw;F vjpuhfTk;> tpLgl;l njhlh;G rk;ge;jkhf gpur;rhuk; nra;fpd;wdh;.

vYk;G jlaq;fspy; caphpapy; gpiofs;

Ks;se;jz;Ls;s caphpdq;fs; gbkq;fshf gbAk; NghJ mit vYk;Gfis jtpu NtW vijAk; tpl;L itg;gjpy;iy. ,Ug;gpDk; vYk;Gfs; Ks;se;jz;L caphpaypd; kpfr;rpwpa msT jlaq;fisNa tpl;L itf;Fk;. mjhtJ 1 rjtPjk;. xU caphpdj;jpd; gbkq;fis Ma;T nra;Ak; NghJ mjd; caphpay; rk;ge;jkhd ngUksT jfty;fs; mope;J Nghfpd;wd. ghpzhkthjpfs; caphpdj;jpd; kpf nky;ypa jpRf;fspd; caphpay; jfty;fs; ,d;ikahy;> mth;fs; Vw;fdNt jpl;lkpl;lgb> ghpzhk Nfhl;ghl;bdhy; %is ryit nra;ag;gl;l mwpit nfhz;L me;j ,ilntspfis epug;Gfpd;wdh;.

ghpzhkthjpfs; vYk;Gfis khj;jpuk; ghh;j;J ,ilepiyfis cUthf;Ffpd;wdh;. mit midj;Jk; kpfTk; gytPdkhd rpe;jidNa. %yf;$W caphpayhsh; ikf;fy; nld;ld; mtuJ A Theory in Crisis vd;w Gj;jfj;jpy; ,ij kpf njspthf Fwpg;gpLfpwhh;:

mope;J Nghd FOf;fspy; nky;ypa caphpaiy cWjpahf mwpe;J nfhs;s KbahJ. MfNt kpf rhpahdjhf Njhd;wf;$ba ,ilepiyfs; cWjpaw;wjhfp tpLfpwJ.  (Michael Denton, Evolution: A Theory in Crisis, Burnett Books: London, 1985, p. 180)

ghpzhkthjpfs; kpf rhpahdjhf Njhd;wf;$ba ,ilepiyfs; $l mth;fis Vkhw;wptpl;lJ. ,jw;F rpwe;j cjhuzk;> nfhyfhd;e;j; (Coelacanth phenomenon.) epfo;thFk;.

nfhyfhd;e;j; epfo;TfspypUe;J ghpzhkthjpfs; ve;j ghlj;ijAk; gbf;ftpy;iy vd;gij juTfs; Rl;bf;fhl;Lfpd;wd.

jw;Nghja bf;lhypf; nuhrpah gbkj;ij Nghd;W> rpy Mz;LfSf;F Kd;G nfhyfhd;e;j; vd;w kPid ePhpypUe;J epyj;jpw;F khw;wkile;j tpLgl;l njhlh;G vd;gjhf fUjp kfpo;r;rpaile;jdh;. Kd;G mope;j Nghd caphpdkhf fUjpa ghpzhkthjpfs; 4000 yl;rk; Mz;Lfs; goiktha;e;j nfhyfhd;e;j; gbkq;fis Ma;T nra;J mjpypUe;J gy ghpzhk jpl;lq;fis tiue;jdh;. cjhuzkhf> mjd; nrjpypYs;s vYk;G Nghd;w mikg;ghdJ me;j caphpdj;ij ePhpypUe;J epyj;ij Nehf;fp elf;f cjtpaJ vd;wdh;. NkYk; mjw;F ,ug;ig ,Ue;jJ vd;Wk; $wpdh;. ,q;F ftdpf;fg;gl Ntz;ba kpf Kf;fpa fUj;J ,Jjhd;: ,e;j KbTfs; midj;Jk; nfhyfhd;e;j; gbkj;jpd; nky;ypa jpRf;fs; gw;wpa ve;j jfty;fSk; ,y;yhj epiyapy; fw;gid nra;ag;gl;lJ.

caphpdj;jpd; nky;ypa jpRf;fs; rk;ge;khf jfty;fs; ,y;yhj epiyapy; ghpzhk fw;gidfis fl;ltpo;j;J tpLk; jtwhd Nghf;F 1938k; Mz;L ,lk;ngw;w Kf;fpakhd fz;Lgpbg;G %yk; njhpate;jJ. capUs;s nfhyfhd;e;j; ,d kPd; xd;W gpbgl;ljd; %yk;> mit Kd;G mope;J Nghd caphpdk; vd;w ghpzhkthjpfspd; fw;gid ngUk; ngha; vd;gJ njhpate;jJ. NkYk; mjid njhlh;e;J NkYk; gy mNj ,d kPd;fs; gpbf;fg;gl;ld. clNd ghpzhkthjpfs; kPdpd; clyikg;ig Muha;e;J mjd; ,aw;ifahd #o;epiyapy; mjd; elkhl;lj;ij Ma;T nra;J> mth;fs; Kd;G fw;gid nra;j ,ilepiy vd;w epiy jtwhdJ vd;gij Ghpe;J nfhz;ldh;. Mok; Fiwe;j ,lj;jpy; tho;e;J ePhpy; jto;e;J nrd;w kPd; vd;W mth;fs; fw;gid nra;j kPd;> cz;ikapy; 180 mb Moj;jpy; tho;e;J tUfpwJ. NkYk; mjd; nrjpy;fs; xU NghJk; fly; Xuq;fis njhltpy;iy vd;gij mth;fs; fz;L gpbj;jdh;;. ,iug;ig vd;W mth;fs; fw;gid nra;jJ cz;ikapy; nfhOg;Gfs; epiwe;j ePe;j cjtpaNj jtpu> mJ Rthrj;Jld; vt;tifapYk; njhlh;G gltpy;iy.

Kd;G ghpzhkthjpfspd; ,ilepiyf;F ek;gpf;if el;rj;jpukhf ,Ue;j nfhyfhd;e;j;> xU rhjhuzkhd kPdpdk; vd;gij Nghd;W mth;fs; jw;NghJ fw;gid nra;Ak; gbkKk; mNj epiyia milAk;. Vnddpy; ,e;j Gjpa gbkKk; Kw;W KOjhf fw;gidapy; fl;bnaOg;gl;Ls;sJ. nfhyfhd;e;j; Nghd;W mope;J Nghd caphpdj;jpd; ,e;j gbkj;jpd; nky;ypa jpRf;fs; fw;gid jfty;fis nfhz;L epug;gl;Ls;sJ. RUq;f nrhy;tjhapd;> jw;NghJ kPBahf;fs; %yk; gug;gg;gLk; ,e;j fw;gid fijahdJ tpQ;Qhdj;jpd; njsptw;w $w;Wfis ikakhf nfhz;L ghpzhk fdTfis mbg;gilahf nfhz;L tiuag;gl;Ls;sJ

ghpzhkthjpfspd; tpLgl;l njhlh;G (missing link) vd;w gpur;rhuk; mth;fspd; rpe;jidf;F vjpuhdJ.

tpLgl;l njhlh;G rk;ge;jkhd fz;Lgpbg;Gfs; vd;W $wg;gl;lTld;> ghpzhk kPbahf;fs; kpfTk; mhpjhd fz;Lgpbg;G xd;W fz;Lgpbf;fg;gl;Ls;sij Nghd;w Njhw;wj;ij Vw;gLj;Jfpd;wd. cz;ikapy; ,J mth;fspd; ghpzhkk; njhlh;ghd thjq;fis kWf;fpwJ.

ghpzhk tsh;r;rp Nfhl;ghL cz;ikahf ,Ue;jhy;> cyfk; KOtJk; ,ilepiy njhlh;ghd gbkq;fshy; epiwe;J fhzg;gl Ntz;Lk;. mjd; vz;zpf;if ,jw;F Kd;G tho;e;j kw;Wk; ,d;W thOk; caphpdq;fspd; vz;zpf;ifia tpl gy klq;F mjpfkhf ,Uf;Fk;. MfNt tpLgl;l njhlh;G rk;ge;jkhd nra;jpfs; md;whl nra;jpahf ,Ug;gjhy; - mjw;F ve;j kjpg;Gk; ,Uf;fhJ.

GtpaPh;ig Nghd;W ghpzhkj;jpw;Fk; gy Mjhuq;fs; ,Ug;jhf ghpzhkthjpfs; $WtJ cz;iknad;why;> tpLgl;l njhlh;G rk;ge;jkhd fz;Lgpbg;Gfs; thid Nehf;fp vwpag;gLk; fy;iy Nghd;W klikahd epfo;thf ,Uf;Fk;. ehk; thid Nehf;fp fy;iy vwpe;Njhk;. mJ kPz;Lk; G+kpia Nehf;fp te;jJ vd;W nra;jpapy; tUk; thpfs; vt;tsT Kf;fpaj;Jtk; ,y;iyNah mij Nghd;W Ma;thsh;fs; Gjpa tpLgl;l njhlh;ig fz;Lgpbj;Js;sdh; vd;w nra;jpAk; Kf;fpaj;Jtk; ,y;yhjjhFk;. RUq;f nrhd;dhy; ghpzhk tsh;r;rp cz;iknad;why; tpLgl;l njhlh;G rk;ge;jkhd gpur;rhuk; Njitaw;wJ.

ghpzhk njhlhpy; bf;lhypf; Nuhrpah Vw;fdNt jPh;khdpf;fg;gl;Ls;sJ

jw;NghJ fz;Lgpbf;fg;gl;Ls;s gbkk; mfd;njh];nlfh (Acanthostega) kw;Wk; ,A];njndhg;nlud; (Eusthenopteron) vd;gtw;Wf;F ,ilapy; Eiof;fg;gl;Ls;sij gj;jphpf;iffspy; gbj;jpUg;gPh;fs;. ,t;thW nra;tjd; %yk; ,e;j gbkk; ghpzhkk; miltij cz;ik gLj;JtjhfTk; xt;nthU ehSk; rhd;Wfs; Ftpe;j tz;zk; cs;sij Nghd;w khiaia ghpzhkthjpfs; fhl;l Kw;gLfpd;wdh;. cz;ikapy; caphpdq;fs; ,t;thW ghpzhkk; miltjw;F ,e;j njhlhpy; ve;j rhd;Wk; ,y;iy. cjhuzkhf jpUfhzpfis (row of screwdrivers)mjd; msTf;F Vw;g mLf;fp itg;gjhy; mJ xd;wpypUe;J kw;waJ Njhd;wpajw;fhd rhd;whf vLj;J nfhs;s KbahJ.

cz;ikapy; ,A];njndhg;nlud; Kjy; bf;lhypf; Nuhrpah tiuAk; my;yJ mfd;njh];nlfh Kjy; bf;lhypf; Nuhrpah tiuAk; ghpzhk njhlh;G ,y;iy. ,e;j caphpdq;fs; xt;nthd;Wf;Fk; ,ilapy; gy kpy;ypad; tUlq;fs; fhy tpj;jpahrk; kw;Wk; gy NtWghLfSk; fhzg;gLfpd;wd. ghpzhkthjpfs; mth;fsJ fw;gidf;F Vw;w tifapy; njhliu tiue;J mjpy; bf;lhypf; Nuhrpahit Eioj;Js;sdh;. Ner;rh; rQ;rpifapd; Mrphpah; n`d;wp fP Henry Gee) tpLgl;l njhlh;GfSk; ghpzhk njhlUk; Vw;fdNt jPl;ba jpl;lk; vd;gij xg;Gf; nfhs;fpwhh:

Gjpa gbk fz;Lgpbg;Gfs; Vw;fdNt cs;s fijapy; nghWj;jg;gLfpwJ. ehk; ,e;j Gjpa fz;Lgpbg;Gfis tpLgl;l njhlh;G vd;W miof;fpNwhk;. %jhij kw;Wk; gpd; Njhd;wy;fSk; vkJ fw;gidf;F cz;ikahdJ vd;W $wg;gl;l NghjpYk; mJ cz;ikapy; mt;thW ,Uf;ftpy;iy. ,e;j cz;ikfis kdpjd; KOtJkhf cUthf;fp> mtdJ fw;gidf;F vw;g mij tbtikj;jhd;. Xt;nthU gbkKk; xU ntw;wplj;ij fhl;LfpwJ> mJ NtW ve;j gbkj;JlDk; njhlh;G gltpy;iy. mtw;Wf;F ,ilNa flysT ,ilntsp fhzg;gLfpwJ. (Henry Gee, In Search of Deep Time, Beyond the Fossil Record to a New History of Life, p. 32)

 

ePhpypUe;J epyj;jpw;F khw;wkiljy; vd;gJ fl;Lf;fij : mJ xU khia

Fwpf;Nfhs;fsw;W khw;wile;j (random mutations) ,izg;Gfshy; Vw;gl;l ed;ikahd NtWghLfspd; fhuzkhfNt caphpdq;fspy; khw;wq;fs; Vw;gl;ld vd;W ghpzhk tsh;r;rp Nfhl;ghL thjpLfpwJ. ,Ug;gpDk; khw;wq;fs; ed;ikaspf;fhJ vd;gJ cyfwpe;j cz;ik. caphpdq;fspypYs;s kugZf;fSf;Fs; (DNA) Gjpa jfty;fis ,izg;gjd; %yk; ghpzhkk; mila nra;a KbahJ. mt;thW GFJ;jg;gLk; khw;wq;fs; caphpdq;fspypYs;s kugZ jfty;fis ehrkhf;fptpLk;. ,jd; KbT cly; cUFiyAk; my;yJ kuzk;. ,jw;F fhuzk; kugZ juthpir kpfTk; EDf;fkhdJ. ,jpy; khw;wq;fs; Vw;gl;lhy; mJ jPq;fhfNt mikAk;. cjhuzkhf xU ,yj;jpudpay; fUtpapy; gjpag;gl;Ls;s vOj;Jfis khw;Wtjd; %yk; mJ xU ,yf;fpa Gj;jfkhf khw;wkilahJ. mJ me;j fUtpapYs;s jfty;fisAk; mjd; nraw;ghLfisAk; mopj;JtpLfpwJ. mijg;Nghd;Nw xU kPdpd; kugZtpy; Vw;gl;l khw;wq;fs; fhuzkhf mjd; vYk;G $L Rik jhq;f $bajhf khWtNjh> ntg;gepiy rPuhf;Fk; mikg;igNah my;yJ jz;zPiu gad;gLj;Jk; mikg;G (rpWePufj;ij Nghd;w kpf rpf;fyhd mikg;ghf) my;yJ nrjpy;fs; ,ug;igahf khw;wkiltJ xUnghJk; rhj;jpag;glhj xd;W.

kPd; gy topfspy;> mjhtJ mjd; Rthr njhFjp (respiratory system)> mjd; ntspNaw;Wk; njhFjp (excretory mechanism) kw;Wk; vYk;G mikg;Gfs; Nghd;wit Ntfkhf khw;wkiltjpy;iy vd;gJ njspthf njhpfpwJ. mt;thW Vw;gl;lhy; mJ ,we;JtpLk;. mj;jifa khw;wkilAk; thpir Vw;gl Ntz;Lk; vd;why; kPDf;F clNd xNu Neuj;jpy; ,ug;ig Vw;gl;L> mjd; nrjpy;fs; fhy;fhshfTk;> mjpy; rpWePufk; cUthfp> mjw;F ePiu jf;fitj;J nfhs;Sk; mikg;Gila NjhYk;; cUthf Ntz;Lk;. caphpdq;fspy; mj;jifa kpf Kf;fpa mikg;Gfs; xNu Neuj;jpy; khw;wkila Ntz;Lk; my;yJ mt;thW xU NghJk; eilngwf;$lhJ. ,t;thW xNu Neuj;jpy; khw;wq;fs; Vw;gLtJ ghpzhk tsh;r;rp Nfhl;ghl;bw;F vjph;khw;wkhdJ> Vnddpy; ghpzhkk; vd;gJ jw;nrayhfTk; vt;tpj Fwpf;Nfhs;fSk; ,d;wp ,lk; ngwNtz;Lk;. gFj;jwpTila xUth; kPDk; ,ju caphpdq;fSk; jdpj;jdpNa gilf;fg;gl;ld vd;gJ jhd; Vw;W nfhs;sf;$ba tpsf;fk; vd;gij Ghpe;J nfhs;thh;.

RUq;f nrhd;dhy;> ePhpypUe;J epyj;jpw;F khw;wkiljy; vd;w fw;gid mjd; Kbit mile;J tpl;lJ. ,ij tpsf;f$ba cWjpahd ve;j gbkj;ijAk; ,Jtiu ghpzhkthjpfs; fhl;ltpy;iy. ghpzhkthjpahd ghh;guh ];lh`;y; (Barbara J. Stahl) mtuJ Vertebrate History: Problems in Evolution vd;w Gj;jfj;jpy; ,t;thW vOJfpwhh;:

vkf;F njhpe;j ve;j kPDk; Ke;ja epyj;jpy; tho;e;j Ks;se;jz;Ls;s caphpdq;fspd; Neub %jhijahf ,y;iy. mtw;wpy; mjpfkhditfs; Kjy; mk;gpgpad;Rfs; (amphibians) Njhd;wpa gpwNf tho;e;Js;sd. mjw;F Kd;dh; te;jitfspy; nll;unghl;fis (tetrapods) Nghd;w cWjpahd cWg;Gfis Njhd;pajw;fhd ve;j rhd;Wk; ,y;iy. (Barbara J. Stahl, Vertebrate History: Problems in Evolution, Dover, 1985, p. 148)

 

KbTiw : `pl;yh; tpl;L nrd;w ngha;ahd gpur;rhu topJiwfs; %yk; ntw;wp ngwKbahJ vd;gij ghpzhkthjpfs; czh;e;J nfhs;sNtz;Lk;.

NkNy Fwpg;gplg;gl;lij Nghd;W tpLgl;l njhlh;G vd;w rpe;jid gbkq;fspy; ve;j cjtpAk; ,d;wp tpQ;Qhdj;jpw;F vjpuhdJ kl;Lky;y ghpzhk tsh;r;rp Nfhl;ghL tho itf;f Ntz;Lk; vd;w xNu fhuzj;jpw;fhf cgNahfpf;fg;gLfpwJ. ,e;j fl;Lf;fijfspy; lhh;tpdp];Lfspd; kPBahf;fs; kpf cWjpahf gpur;rhuk; nra;tJ nghJkf;fs; kj;jpapy; mth;fspd; ghpzhk rpe;jidia gug;g Ntz;Lk; vd;gjw;fhfthFk;. ghpzhkthjpfsplk; mth;fsJ gpioahd Nfhl;ghl;il cz;ikgLj;jf;$ba ve;j rhd;Wk; ,y;iy. ,J tpQ;Qhd tuyhw;wpy; Ngrg;gl;l ngUk; ngha;. Xd;wd; gpd; xd;whf tPo;r;rpaile;j nfhyfhd;e;j; (Coelacanth) kw;Wk; Mh;\pag;nlhpf;]; (Archaeopteryx) Nghd;w gbkq;fs;> Kd;G ghpzhkj;jpw;fhf thjhba ,f;tpAd; thpir (equine series) Nghd;witfis Muha;e;J ghh;j;jhy; tpLgl;l njhlh;G nghJkf;fs; kj;jpapy; capUld; itf;f Ntz;Lk; vd;gjw;fhfNt ,it fhyj;jpw;F fhyk; cap&l;lg;gLs;sij fhzyhk;.

,e;j Kaw;rpfs; midj;Jk; `pl;lyhpd; nkhopapy; nrhy;tjhdhy; kPz;Lk; kPz;Lk; Ngrg;gLk; ngha; cz;ikahfptpLk; vd;w gpur;rhu topfshFk;.

Ma;Tfs; mth;fsJ Nfhl;ghl;il kWf;fpwJ vd;gij ghpzhkthjpfs; Vw;W nfhs;sNtz;Lk;. tpLgl;l njhlh;G vd;w fl;Lf;fijia xU NghJk; cz;ikahf Nghtjpy;iy.

1- Daeschler et al., "A Devonian tetrapod-like fish and the evolution of the tetrapod body plan," Nature 440, 757-763 (6 April 2006)
2- Shubin et al., "The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb," Nature 440, 764-771 (6 April 2006)
3- Per Erik Ahlberg and Jennifer A. Clack, "Palaeontology: A firm step from water to land," Nature 440, 747-749 (6 April 2006)