Between 1870-1920, Darwin’s theory went through a period of doubt, as scientists could not see how information needed to create new species could be passed on - ### Gregor Mendel Gregor Mendel; > gained posthumous recognition as the founder of the modern science of [genetics](https://en.m.wikipedia.org/wiki/Genetics "Genetics").[[5]](https://en.m.wikipedia.org/wiki/Gregor_Mendel#cite_note-:4-5) Though farmers had known for millennia that crossbreeding of [[Animals]] and plants could favor certain desirable [traits](https://en.m.wikipedia.org/wiki/Trait_(biological) "Trait (biological)"), Mendel's [pea](https://en.m.wikipedia.org/wiki/Pea "Pea") plant experiments conducted between 1856 and 1863 established many of the rules of [heredity](https://en.m.wikipedia.org/wiki/Biological_inheritance "Biological inheritance"), now referred to as the laws of [Mendelian inheritance](https://en.m.wikipedia.org/wiki/Mendelian_inheritance "Mendelian inheritance"). During the 1920’s, 30’s & 40’s however developments in genetics revived Darwinism. ### Hermann Joseph Muller In 1918, proposed an explanation for the dramatic discontinuous alterations in _[Oenothera lamarckiana](https://en.m.wikipedia.org/wiki/Oenothera_lamarckiana "Oenothera lamarckiana")_ that were the basis of [Hugo de Vries](https://en.m.wikipedia.org/wiki/Hugo_de_Vries "Hugo de Vries")'s theory of [mutationism](https://en.m.wikipedia.org/wiki/Mutationism "Mutationism"): "balanced lethals" allowed the accumulation of recessive mutations, and rare [crossing over](https://en.m.wikipedia.org/wiki/Chromosomal_crossover "Chromosomal crossover")events resulted in the sudden expression of these hidden traits. In other words, de Vries's experiments were explainable by the Mendelian-chromosome theory. Through the work of people like George Gaylord Simpson in the 30’s and 40’s Neo-Darwinism was born. ### Claude Shannon [](https://en.wikipedia.org/wiki/Claude_Shannon) known as the ‘Father of information theory.’ There are two main types of information that scientists study. Functional/meaningful information and so called ‘Shannon’ information, which is not necessarily functional or meaningful. The more uncertainty that is conveyed, the more information is needed. [[Evolution]]