Evolution and Adaptation

acquired characters adaptation adult advantage amongst ancestors animals and plants aphids appear arisen artificial selection assume become believe birds breed caterpillars causes cells color connection crustaceans Darwin Darwinian degeneration degrees descendants direction Draba verna eggs elementary species embryo environment evidence evolution exist experiments explain fact females fertilized flowers fluctuating variations gemmules geotropic germ-cells give heliotropic hybrid hypothesis important individuals inheritance of acquired insects instance instinct kind Lamarck Lamarckian large number larvæ later less light living long-styled males mammals ment moths mutation theory Nägeli natural selection occur offspring organs origin ornaments outcome pangenesis parent form parthenogenetic pistil polar body pollen present probable produced question race regard relation reproduction resemblance response result rotifers secondary sexual characters seeds sexual selection short-styled shown side sort spermatozoon stages stamens structure supposed takes place tion tropisms variability varieties Vries Weismann wings young