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Hugo de Vries, a Dutch botanist proposed mutation theory to explain the mechanism of evolution. His theory was published in 1901 in his book "Die Mutation Theorie". He performed experiments on the evening primrose (Oenothera lamarckiana). According to him, mutations are sudden and heritable changes that are subjected to natural selection.
According to Hugo de Vries, mutations are random and directionless. De Vries believed mutations caused speciation and hence called saltation (single step large mutation). So, the correct answer is ' Random and directionless'
Hugo de Vries believed that mutation causes species formation and this is known as saltation. Saltation is the single step large mutation which results in the formation of new and advanced species. He believed that the minor heritable variations which were mentioned by Darwin was not responsible for evolution.
De Vries gave his mutation theory on organic evolution while working on Oenothera lamarckiana. Oenothera lamarckiana is an annual plant commonly called as evening primose. De Vries in his experiment observed that original plant showed some offsprings with different phenotypes. These mutations were passed from offsprings to their progeny.
Hugo de Vries proposed “mutation theory of evolution” while working on. View Solution ...
The theory of mutation given by Hugo de Vries suggested that evolution is fueled by the occurrence of the discontinuous process called mutation, that arises in the genetic material suddenly and are transmitted to the next generation. These mutations serve as raw material for evolution as they may provide a selective advantage to an individual.
There are several theories that try to explain the mechanism of organic evolution which includes, lamarckism, darwinism, mutation theory by Hugo de Vries. Huxley is also associated with organic evolution. The pioneers in the field of 'organic evolution' are Darwin, Hugo de Vries, Lamarck and Huxley. Thus, option A is correct.
Hugo de Vries gave a theory of evolution, called 'Mutation theory' which states that evolution is a jerky process where new varieties and species are formed by mutation. So. the correct answer is 'Theory of Mutation'
According to de Vries, saltation means single-step large mutations arising suddenly in a population causing evolution. In biology, saltation is a sudden change from one generation to the next, that is large, or very large, in comparison with the usual variation of an organism. Was this answer helpful?
Evolution is a change in the gene frequencies in a population in responseto changes in the environment in a time scale of years and not centuries. Justify this statement with reference to DDT. How does the theory of Hugo de Vries support this?
