The Immune System: The Three Causes Of Selection

Selection is the idea that individuals in a given population with certain traits will survive and produce more offspring because they have certain desired traits. In turn, this will create a change in the population. There are three main ingredients that are necessary for selection to occur within a population. These three ingredients are variation, differential success, and heredity. Variation is the differences among individuals in the composition of their genes. Genes are what determine our traits, therefore variation is the differences in traits in the individuals in a population. The three causes of variation are mutations, sexual reproduction, and gene duplication. Differential success is the contribution of an individual in the …show more content…
The immune system is made up of immune cells in body fluids and in tissues that interact and destroy pathogens in the body. One of the biggest parts of the immune system are antibodies. Antibodies are proteins that are produced by plasma cells with the purpose of killing pathogens. Antibodies work by recognizing antigens on the surface of pathogens. When looking at variation in the immune system, we must look at all the different types of antibodies in the immune system. In a given immune system, there are many different types of antibodies. A antibody is shaped like the letter Y and at the tip of this Y there is what are called paratopes. Paratopes are specific to certain antigens. Therefore, the variation in the immune system is the different antibodies that each are specific to different types of antigens. When looking at which antibodies are best fit to fight a pathogen in the immune system, we look at differential success. The antibody that best recognizes the antigen on the pathogen is going to be the antibody that defeats the pathogen. This would make that antibody the fittest. Since the antibodies that were able to detect the antigens defeated the pathogen this makes them the fittest, and will be the ones that get passed down to the offspring. Mothers are able to pass down antibodies to their offspring. When the mother produces antibodies to fight certain viruses and bacterias, those antibodies now stay in her body. When the mother produces offspring, these already produced antibodies will be paced down to her offspring. This process shows the heritability within the immune system. The immune system is one of the many things that utilizes the three ingredients of