All cells of an organism contribute gemmules to the reproductive cells. The inherited gemmules blend together in the offspring.
Lived in 1800. Developed the theory of inheritance of acquired characteristics over a lifetime of an individual organism. He is also known for coining the terms "biology" and "invertebrates".
Lamarck's view on how organisms rose from inorganic material. Organisms arose separately, and the time since they became monads is attributed to the complexity of the organism.
Major evidence for modern evolutionary biologists as transition forms. Fossils for Larmarck are not extinct, just in between forms still living.
Spencer, Cope, Agaziz, Bergson, Teihard de Chardin. Believed in orthogenesis, developed in the 1950s. Mostly made of philosophers and geologists. Inherited changes are caused by many factors, including the environment.
All species evolve toward perfection by an internal (religious) force. Also known as the Omega point.
Darwin's major theory, otherwise known as (unfortunately) "survival of the fittest. Has four postulates.
Four Postulates of Natural Selection
More offspring are produced than can be supported in the environment (struggle for existence), there is variation between individuals, some variation is inherited by individuals, individuals that possess better variation have a greater chance of reproducing than those carrying maladaptive variations.
English naturalist who formulated a concept of evolution that resembled Charles Darwin's (1823-1913). He was discredited by many scientists for his partaking in "woo-woo". He is however credited with his theory of biogeography.
Darwin's cousin that rejected pangenesis. Believed characters can be conserved over long lineages and do not blend or dilute out.
A german microscopist who proposed nuclear division as the basis for heredity in cells. Also developed the germ plasm theory. Also disproved theory of inheritance of acquired characteristics by cutting the tails of mice off.
Central Dogma of Molecular Biology
Coded info in DNA is transcribed into an RNA copy of the code, & the code is used to assemble amino acids into a protein (polypeptide) via translation. Similar to the Germ Plasm Theory
(Mendelian) Observed that pangenes are inherited according to predictable patterns. He also discovered Mendel's paper and popularized it. He coined the term mutation.(1900)
The father of genetics. Studies on pea plants showed plant hybrids. Is not a Mendelian, because he did not understand the significance of his work.
Darwinian evolution stripped of all theories surrounding pangenesis or Lamarckian ideas.
(Mendelian) Tried to discredit Darwin. Supported Mendel's paper and advocated that discontinuous variation is most important in species formation. He also coined the terms "segregation", "genetics", "allelomorph" (allele), "homozygote", "heterozygote", "F1", "F2". He published a book called Mendel's Principles of Heredity.
Bateson, DeVries, Morgan. Were geneticists that claimed that evolutionary change is due to mutations (spontaneous gene alternations), and that discontinuous variation is the most significant.
(Mendelian) United States biologist who formulated the chromosome theory of heredity (1866-1945)
Weismann, Jordan and Kellogg. Naturalists that postulated that Natural Selection the major factor that's responsible for evolution. Evolution is gradual and occurs exclusively at the level of continuous variation.
Started to resolve the Mendelian-Darwinian controversy with using bean length which showed continuous character with a genetic component.
Weldon, Pearson. Mostly statisticians. Believed that ancestry and individual differences are the materials of evolution. Looked at continuous traits.
Demonstrated genetic evidence for continuous traits with polygenic inheritance. Demonstrated wheat pigmentation has three alleles involved with incomplete dominance.
Incomplete dominance without complete additivity
Three phenotypes for two alleles, where the heterozygote phenotype is somewhere between the two homozygote phenotypes.
Incomplete dominance with complete additivity
Three phenotypes for two alleles, where the heterozygote phenotype is an average of the two homozygote phenotypes. E.g.) Red and white makes a pink heterozygote.
Both the homozygote phenotypes are expressed in the heterozygote. E.g.) A + B blood types make AB blood with both A&B receptors.
Published the Evolution of Living Organisms (1912). It supported Mendel and Darwin, because it explained how random mutations are the cause of variation, and that organisms are subject to environmental modification, but this is not inherited. He proposed that natural selection allows for a filter for these mutation. He publicized the peppered moth (discontinuous) and Bumpus' sparrows (continuous) experiments.
Shows that in the absence of external forces, allele frequencies remain constant through generations of random mating. It is only useful in diploid organisms.
(1930s) Statistician that stated that there is no contradiction between Mendelian genetics and evolution by natural selection. This is because Mendelian inheritance does not alter allele frequencies, selection is the most effective source of change, and that mutation and chance play minor roles. He moved the talk away from variation and toward individual alleles. Showed that discrete alleles did not blend.
(1930s) Showed how Mendelian genetics can predict complex traits. Also showed the power of selection. Also showed the significance of population size and coined "genetic drift".
Moved to the US and became a professor and influenced geneticists on the importance of natural selection of continuous characteristics. He postulated that speciation requires isolation. He used Drosophila as evidence. Co-founded the biological species definition. (1900s)
Ornithologists supported Dobzhansky, showed own research for speciation. Co-founded the biological species definition.
Evolve separately because of geographic separation and then genetic divergence occurs.
Selection and Variation
Was used to attack, but with electrophoretic studies of wild populations, it is possible to see that there is tremendous variation between individuals.
Neutral Theory of Molecular evolution
Proposed because there is so much variation, that most polymorphic traits are selectively neutral and evolve through drift. Used to invalidate Natural Selection, but cannot in many cases. Invented by Kimura. (1960s)
Evolutionary model suggesting species often diverge in spurts of relatively rapid change, followed by long periods of little change. Proposed by Elderedge and Gould.
Darwinian Theory Of Evolution
Proposed by Mayr. 1. Evolution (genetic change), 2. Common descent of species, 3. Diversification by speciation. 4. Gradualism. 5. Natural Selection.
Applying Darwin's theories as a justification for evil political or economic persuits and vehicles for the dissemination of pseudoscientific bigotry.