. Civic biology; textbook of problems, local and national, that can be solved only by civic coöperation. Biology. 1M;A( TICAl, LAWS ol" lAVK :i:i' (i^-r^. liiqluT than till' worms and soim* iiisft-ts have cuiiil* to (h*- peiid upon it entirely. In st-xnal iv[)ro(hiction each indi- vidual is huilt n[) hy the niini»-linL; of the j^^crniinal rlcnimls of two parents, and nol only that, hut of fom- L^randpareiils, eiyht great nrand[)arL'nls, and so on. This niin'^lin*^, hv pre- poteiiee of some characters and recession of others, causes active variation, an() per cent of Ins characters from hi
. Civic biology; textbook of problems, local and national, that can be solved only by civic coöperation. Biology. 1M;A( TICAl, LAWS ol" lAVK :i:i' (i^-r^. liiqluT than till' worms and soim* iiisft-ts have cuiiil* to (h*- peiid upon it entirely. In st-xnal iv[)ro(hiction each indi- vidual is huilt n[) hy the niini»-linL; of the j^^crniinal rlcnimls of two parents, and nol only that, hut of fom- L^randpareiils, eiyht great nrand[)arL'nls, and so on. This niin'^lin*^, hv pre- poteiiee of some characters and recession of others, causes active variation, an() per cent of Ins characters from his ^^^^^ ^^ parents, 25 per cent (£^hHp from his grandpar- ents, and tlie rest from more remote an- cestors. (ii\en all the forces of increase, va- riation, and heredity, another law comes hito play, the discovery of which was Darwin's great contribution. The law of natural selection. Xttfurr srirrfx fhc fittest tn survive. From the becfinidno-, man has imitati'd nature in selectino- the i)lants and animals that suit his need or fanev, and this is connnonly distiiiLiuisluMl as ((r(.'fict\t/ .srhctiou. Combination of tliese two ])rocesses has resulted in \]\o sp(»- cies and varieties, strains and breeds, that we nnw .sec in the world. Progress has been made in the [tast chielly by pick- ing up chance variations as they have occurred in nature and accidentally among domesticated j)lants and animals. ()nly within recent years haxc we begun to learn how to sidi'ct the parents in order to cause desired vaiiations. \\\ eight years of most accui-alc :nid ]iainstaking experiments in cn^ss- ing and rearing \arietics of garden ju-as, the Austrian monk. (dd) @)~T~@) ^^ ^® abviuf. Vu,. 104. Diaiirani illustratiiiLr Mt'iidel's law of (lihybrids. white lu-iiii,^ (l(»iniiiiiiit and black recessive. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly
Size: 1648px × 1516px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcontributorncsu, bookpublisherbostonginn, booksubjectbiology
