Evolution
...laimed that parts of the body that is used more often become larger and stronger while those that are not used reduce in size. He believed that organisms choose to evolve to fit the environment. 2. He stated that characteristics and modification an organism acquires during its lifetime can be passed on to its offspring. Lamarck’s theories were largely erroneous, but they non-the less played an important role in setting the scene for scientists such as Charles Darwin. Alfred Russel Wallace was a British naturalist, geographer, anthropologist and biologist. Wallace’s independent proposal of a theory of evolution by “Natural Selection” prompted Charles Darwin to reveal his own more developed and researched theory sooner than intended, but unfortunately was unpublished. At one point Wallace had met Charles Darwin and was once one of Darwin’s correspondents from around the world, whose observations Darwin used to support his theories. Wallace and Darwin corresponded manuscripts on the theories of evolution and later Wallace described the novel theory of “Natural Selection”, and proposed that it explains the diversity of life, it was essentially the same as the theory that Darwin had worked on for 20 years. This resulted in joint paper read before the Linnean Society and was published a year later. Wallace had later given credit throughout his life to Darwin and in doing Darwin reciprocated by arranging government pension and assorted honors for Wallace. The British Naturalist Charles Darwin (1809-1882), had formed a theory which is still used today, his theory had four basic guidelines, 1. Evolution did occur 2. Evolutionary change was gradual, requiring thousands to millions of years 3. The primary mechanism for evolution was a process of “Natural Selection” 4. The millions of species alive today arose from a single original life form through a branching process called “Specialization” Darwin’s theory of evolution selection holds that variation within species occurs randomly and that survival or extinction of each organism is determined by that organism’s ability to adapt to its environment. Charles Darwin had published his theories on evolution in 1859. Darwin’s theory of “Natural Selection” stated that the differential success in reproduction in a population of varied individuals where certain members have traits or adaptations that are better suited to the environment than others. The members with more favorable traits have better chance of survival and therefore end up leaving more offspring than others. These favorable traits are passed on to their offspring and through continuous succession, perpetuate throughout the population, giving rise to adaptation of population of organisms to their environment. Part 2 Evolution requires genetic variation and changes in the gene pools of populations. To allow this to happen, there are several mechanisms that have to take action, such as 1. Random Mating: Involves the mating of individuals regardless of any physical, genetic, or social preferences. It is the mating between two organisms not influenced by the environment or heredity or social interaction. 2. Mutation: are permanent, sometimes transmissible changes to the genetic material of a cell such as DNA and RNA. Mutations can be caused by copying errors in the genetic material during cell division and by exposure to radiation, chemicals, or viruses, or can occur deliberately under cellular control during the processes such as meiosis or hypermutation. In multicellular organisms, mutations can be subdivided into germline mutations, which can be passed on to progeny and somatic mutations which often lead to the malfunction or death of a cell and can cause cancer. Mutations are considered the driving force of evolution, where less favorable mutations are removed from the gene pool by natural selection, while more favorable ones tend to accumulate. Neutral mutations do not affect the organism's chances of survival in its natural environment and can accumulate over time, which might result in what is known as punctuated equilibrium, a disputed interpretation of the fossil record. Contrary to tales of science fiction, the overwh...