Describe the inheritance of traits acquired according to Lamarck's doctrine and how the survival of the fittest creates new species?
Answers
Answer:
Lamarckism, or Lamarckian inheritance, also known as "Neo-Lamarckism",[1] is the notion that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime. This idea is also called 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, and 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. Darwin's own concept of pangenesis implied soft inheritance.
Answer:
Scientists are not always remembered for the ideas they cherished most. In the case of the French biologist Jean-Baptiste Lamarck, his name since the end of the nineteenth century has been tightly linked to the idea of the inheritance of acquired characters. This was indeed an idea that he endorsed, but he did not claim it as his own nor did he give it much thought. He took pride instead in advancing the ideas that (1) nature produced successively all the different forms of life on earth, and (2) environmentally induced behavioral changes lead the way in species change. This article surveys Lamarck’s ideas about organic change, identifies several ironies with respect to how his name is commonly remembered, and suggests that some historical justice might be done by using the adjective “Lamarckian” to denote something more (or other) than a belief in the inheritance of acquired characters.
Explanation:
In addition to those moments when a historical “turning point” is reached without it being recognized as such, there are the more common cases when the converse is true, i.e., when an event that seems important at the time subsequently drops altogether from historical recollection. When the May 1802 scare regarding the elephant’s illness passed, the event seems not to have concerned the professors again, although the animal keepers were surely on the alert never again to allow the elephant to eat an overabundance of fresh grasses. Today, as it happens, Lamarck’s name is routinely associated with giraffes (more on this follows), but virtually never with elephants.
With these two variants on the theme of what seems memorable and what does not, over the course of a scientist’s career, there is a third that applies with special force in Lamarck’s case. This is when someone is remembered for something other than what he or she would have considered to be his or her most significant achievement. Since the end of the nineteenth century, Lamarck’s name has been firmly linked with the idea of the inheritance of acquired characters. More recently, “epigenetic inheritance” has been represented as a form of the transmission of acquired characters and thus as a confirmation, at least of a sort, of Lamarck’s most famous idea (Gissis and Jablonka 2011). As we show in this article, while it is true that Lamarck endorsed the idea of the inheritance of acquired characters and made use of it in his evolutionary theorizing, neither Lamarck nor his contemporaries treated this as Lamarck’s “signature” idea. Certainly he did not claim the idea as his own. Instead, he treated it as commonplace, which it was. He believed it was so transparently obvious that it needed no assemblage of facts or trial by experiment to confirm it.