The Material Basis of Evolution

accumulation action actually adaptational analysis animals antennae basis characters chitin chromosomes cline color completely conception conclusions controlled crosses definite determination developmental diapause differentiation Diptera discs discussion Dobzhansky Drosophila ecotypes effect embryology embryonic evolution evolutionary example exist experimental extreme female ferences formation forms frequently gene mutations genera genetic genetic change geneticists geographic races Goldschmidt growth hereditary Hokkaido hormones hybrids incipient species individual insects intersexuality involved isolation Japan known Lake Biwa Lamarckian larval Lepidoptera Lymantria dispar macroevolution macroevolutionary male material melanic Mendelian mentioned micromutations morphological moth mutations neo-Darwinian norm of reaction normal occur organs orthogenetic parallel phenocopies phenotypic physiological plants polyploidy preadaptation present problem processes produced pupa pupation racial rassenkreis reaction system region relation Rensch result segmentation selection sexual single steps subspecies systemic mutation taxonomic taxonomists temperature theory tion traits typical variation whole wing rudimentation