With respect to the lymphatic system, what are the effects of positive selection, negative selection and anergy?
A term that is related to your question is “Natural Selection”. Charles Darwin coined this in his book “The Origin of the Species”, published in 1859. As applied to modern biology, Natural Selection implies that species possessing a genetic phenotype that promotes reproduction will evolve to predominate over those with less advantageous genetic makeup.
The theory of Natural Selection is that groups inheriting favorable genes enjoy Positive Selection, those without, Negative Selection.
With respect to the lymphatic system (a part of the human immune system) Positive Selection would, in theory, occur for persons inheriting a vigorous and properly functioning immune/lymphatic system.
Conversely, a group of people who were genetically immunodeficient would undergo Negative Selection and, over generations of evolution, disappear.
“Anergy” is a term that is unrelated to natural selection. It is defined as a state of immune unresponsiveness. Patients with anergy have T-cells or B-cells that are unable to participate in the immune process. One example of anergy would be found in a patient with overwhelming infection. Their immune system is exhausted, and no longer able to properly react to immune challenge. This lack of reactivity could spread to conditions other that the specific infection that began the process.