Due to the ongoing change in human health and medicine, evolution has been selective to provide the human species with a higher level of fitness. At the cellular level, genes are made of DNA, which is the genetic blueprint for growth and development. When DNA is replicated and undergoes cell division, there may be errors, known as mutations that occur. After multiple generations of offspring are produced, eventually the mutations will change enough to show a new distinguishable trait such as disease or a particular disorder (Ovchinnikov, Rubin & Swergold, 2002). If the same genes are passed on and carry the traits for a particular disorder, then fitness of the host will be lowered, because of the impact of a certain disease.
The only ones that will survive will be the ones carrying that gene. Therefore, those remaining antibiotic resistant specimens will be able to reproduce, passing along the antibiotic ... ... middle of paper ... ...ntibiotics, which is incorrect. It is distinct that Darwin’s theory is more suited to the evolution of MRSA as it involves concepts of Natural Selection. Methicillin resistant strands have a better chance of surviving and breeding whereas other non-resistant strands die off as they have a lower probability of survival. They adapt to mankind’s defences to generate more breeding grounds of MRSA in humans and animals to generate growth.
This similar reaction is caused by their similar genetic makeup. When we genetically modify an organism it can cause lower genetic diversity as the gene is passed on and more organisms possess this gene. Genetic engineering can also be used by geneticists to “speed up the process of natural selection and remove undesirable traits in an organism quicker than waiting on an organism to evolve to the point that the undesirable trait was no longer present” (citation). Therefore, genetic evolution could increase the speed of
Evolution can be defined as the process through which the characteristics of a species undergo changes over a number of generations through the process of natural selection. There are different mechanisms that try to explain the evolution process and these are mutation, migration, genetic drift and natural selection. However for natural selection and genetic drift to take place there must exist a certain type of genetic variation. To begin with natural selection can be defined as the process through which organisms that are better adapted to a certain environment survive and produce fertile off springs. Organisms that do not seem to adapt in that particular environment are left out.
A mutation that may be an advantage to a pressure in a specific environment may end up changing again to increase advantages in the next generations. Adaptations will change with the environment to create new species and morphologies for best fit species and ultimately for survival. However, mutations occur depending on the population size, a small population may not be able to mutate and adapt as fast as a large population can. A large population tends t... ... middle of paper ... ...being able to pass their genes on from generation to generation. The last disadvantage of sex is recombination.
Natural selection is the process by which random modifications (mutations), related to a distinct individual’s chance of survival by adapting to its environment (food, predators, environmental features), are selected by nature in a total logical way (lecture). Basically, natural selection functions like this: the individuals among a community with the most advantageous characteristics regard to the survival and reproduction rate will spread on these inherent genetic traits to their offspring (Futuyma, 2004). Over time, these traits will become more frequent in the genetic basis of future generations and eventually all the living species within a population will gain those features (lecture). There are three preconditions for natural selection to exist (lecture). The first one is variation.
Selection Pressures are factors that influence the survival of an individual, a population or a species. Some factors include, environmental factors, such as predators/prey, and competition among members of a species for similar limited resources. Genes transmitting successful phenotypes from one individual to another and one generation to another. Selection pressures result in certain phenotypes of an organism being favoured over others ( i.e. The genes that control that organism are selected) and therefore variation results.
Reproductive Isolation (Sympatric Speciation) Reproductive Isolation is a type of genetic isolation. Here the formation of a new species can take place in the same geographical area, e.g. mutations may result in reproductive incompatibility. A new gene producing, say, a hormone, may lead an animal to be rejected from the mainstream group, but breeding may be possible within its own groups of variants. When this mechanism results in the production of a new species it is known as sympatric speciation.
It produces new and different species through ancestral populations of organisms and moves them to new population. Both natural selection and genetic drift decrease genetic variation. If they were the only mechanisms of evolution, populations would eventually become homogeneous and further evolution would be impossible. There are, however, mechanisms that replace variation depleted by selection and drift (Colby). Work Cited Colby, Chris.
The first person who proposed natural selection in 1858 was the English scientist Charles Darwin. According to Darwin’s theory, mutated genetic traits, which allow an individual to survive environmental changes, prevail and are passed on to the offspring. The offspring, having inherited the mutated traits, reproduces again and expands the population with the new traits. This new offspring and population have passed through the process of Natural Selection and survived. In comparison, individuals without the mutated genes or with less desirable traits may have a harder time surviving natural obstacles.