State Lamark and Darwins Theory - 1727 Words

2a) State Lamark and Darwin’s theory and explain the difference using an example Lamark proposed the theory that offspring were able to inherit the traits that were acquired during their parent’s lifetime. He held the belief that organisms altered their behaviour according to their environment, in turn modifying their organs and body structure to best suit their surroundings. The improved structures useful to the organism were then to be inherited by their offspring. Unused organs would deteriorate and eventually be removed from the body overtime. For example, giraffes obtained the useful characteristic of elongated necks and front limbs to reach food in high trees through the straining of their necks. It was believed that that the neck and front limbs would progressively elongate each generation as giraffes stretched further. On the other hand, Darwin believed that genetic variation already existed with a population of organisms. Physical and chemical environmental changes or competition for resources acted as selecting agents for favourable genetic characteristics. The organisms with the genes best adapted to the environment would survive and produce offspring with those favourable traits. Conversely, those with unsuitable traits died off quicker and therefore were less likely to reproduce. Over generations, the organisms with the desirable characteristics would eventually dominate the population. For example, giraffes with the already existing favourable trait ofShow MoreRelatedEvolution Of Evolution And Genetics921 Words   |  4 PagesBiologists have been studying evolution and genetics to further advance human knowledge, discover the human origins, and to eliminate human illnesses. Biologists like Lamark and Darwin have contributed much knowledge to the biology community and have helped many grasp the idea of evolution. But there are still many questions left unanswered; regressive evolution is one of these puzzling questions left unanswered. Cavefishes may help solve the mystery of why regressive evolution occurs and biologists