Question

what is environment and new needs on the basis of lamarckism principle

Answer 1

Lamarckism (or Lamarckian inheritance) is the hypothesis that an organism can pass on characteristics that it has acquired through use or disuse during its lifetime to its offspring. It is also known as the inheritance of acquired characteristics or soft inheritance. It is inaccurately[1][2] named after the French biologist Jean-Baptiste Lamarck (1744–1829), who incorporated the action of soft inheritance into his evolutionary theories as a supplement to his concept of orthogenesis, a drive towards complexity. The theory is cited in textbooks to contrast with Darwinism. This paints a false picture of the history of biology, as Lamarck did not originate the idea of soft inheritance, which was known from the classical era onwards. It was not the primary focus of Lamarck's theory of evolution; further, in On the Origin of Species (1859), Charles Darwin supported the idea of "use and disuse inheritance", though rejecting other aspects of Lamarck's theory.

Many researchers from the 1860s onwards attempted to find evidence for the theory, but these have all been explained away either by other mechanisms such as genetic contamination, or as fraud. Later, Mendelian genetics supplanted the notion of inheritance of acquired traits, eventually leading to the development of the modern synthesis, and the general abandonment of the Lamarckism in biology. Despite this, interest in Lamarckism has continued.

Studies in the field of epigenetics and somatic hypermutation[3][4] have highlighted the possible inheritance of behavioral traits acquired by the previous generation.[5][6][7][8][9] These remain controversial, not least because historians of science have asserted that it is inaccurate to describe transgenerational epigenetic inheritance as a form of Lamarckism.[10][11][12][13] The inheritance of the hologenome, consisting of the genomes of all an organism's symbiotic microbes as well as its own genome, is also somewhat Lamarckian in effect, though entirely Darwinian in its mechanisms.