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Blending inheritance is an obsolete theory in biology from the 19th century. The theory is that the progeny inherits any characteristic as the average of the parents' values of that characteristic. As an example of this, a crossing of a red flower variety with a white variety of the same species would yield pink-flowered offspring.
Blending would therefore directly oppose natural selection. In addition, Darwin and others considered Lamarckian inheritance of acquired characteristics entirely possible, and Darwin's 1868 theory of pangenesis, with contributions to the next generation (gemmules) flowing from all parts of the body, actually implied Lamarckism as well as blending.
Blending inheritance leads to the averaging out of every characteristic, which as the engineer Fleeming Jenkin pointed out, makes evolution by natural selection impossible. The fossil record was discontinuous, suggesting gaps in evolution. [8]
Blending Inheritance Between 1856 and 1865, Gregor Mendel conducted breeding experiments using the pea plant Pisum sativum and traced the inheritance patterns of certain traits. Through these experiments, Mendel saw that the genotypes and phenotypes of the progeny were predictable and that some traits were dominant over others. [ 11 ]
The mediaeval great chain of being as a staircase, implying the possibility of progress: [1] Ramon Lull's Ladder of Ascent and Descent of the Mind, 1305. Alternatives to Darwinian evolution have been proposed by scholars investigating biology to explain signs of evolution and the relatedness of different groups of living things.
The effect, then unnamed, was put forward in 1896 in a paper "A New Factor in Evolution" by the American psychologist James Mark Baldwin, with a second paper in 1897. [1] [2] The paper proposed a mechanism for specific selection for general learning ability.
Population genetics began as a reconciliation of Mendelian inheritance and biostatistics models. Natural selection will only cause evolution if there is enough genetic variation in a population. Before the discovery of Mendelian genetics, one common hypothesis was blending inheritance. But with blending inheritance, genetic variance would be ...
Du Bois-Reymond's exposition resembled Darwin's: he endorsed natural selection, rejected the inheritance of acquired characters, remained silent on the origin of variation, and identified "the altruism of bees, the regeneration of tissue, the effects of exercise, and the inheritance of disadvantageous traits" as puzzles presented by the theory.