Genetics and the Origin of SpeciesGene mutation. Mutation as a basis for racial and specific diferences. Chromosomal changes. Variation in natural populations. selection. Polyploidy. Isolating mechanisms. Hybrid sterility. Patterns of evolution. Species as natural units. |
Contents
ORGANIC DIVERSITY | 3 |
GENE MUTATION | 16 |
MUTATION AS A BASIS FOR RACIAL AND SPECIFIC DIFFERENCES | 51 |
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Common terms and phrases
adaptive alleles allopolyploids ancestral animals autosomes backcross bivalents breeding cells characters chromo chromosomal changes chromosome numbers chromosome pairing colonies color cross cytological cytoplasm diploid distribution Dobzhansky Drosophila melanogaster Drosophila pseudoobscura ecotypes effects eggs environment evolution evolutionary F1 hybrid females fertile formation forms gametes gene arrangement gene combinations gene frequencies gene mutations genera genetic genic genotype genus geographical germ plasm give rise Goldschmidt groups haploid hereditary heterozygotes heterozygous homologous homozygotes homozygous individuals interbreeding intersexes interspecific inversions isolating mechanisms known lethals maize males meiosis meiotic division miranda modifiers morphological mutability mutant genes mutation rates natural populations natural selection normal number of chromosomes observed occur offspring organisms origin parental species percent phenotypic plants polyploid produce race Raphanobrassica recessive sexual similar single sterility strains structure studies Sturtevant tetraploid texana theory third chromosome Timofeeff-Ressovsky tion translocation triploid univalents variability variation viability virilis wild type X chromosome X-ray zygotes