This has also been referred to as genetic 'dark matter' with the notion that many rare mutations have not yet been discovered. Links between autism and schizophrenia have been studied (as above). The implications are both conditions are part of the same spectrum. From clinical observation, both conditions cause a disruption in normative social functioning which may be mild or severe depending on the individual's position within the spectrum. Simon Fraser University researcher Crespi has examined how social cognition is under developed in autism and highly developed in Psychoses and outlines how the relationship between autism and schizophrenic spectrum is not one that has been explored in detail in the latter part of the 20th century. His research hypothesises that the genetic marker for both conditions may lie in the same location. His team have identified four loci that are diametrically opposed in terms of diagnoses of autism and schizophrenia with corresponding deletions for one condition or duplications for the other: Professor Timothy Crow, from the University Department of Psychiatry at Oxford University, has long argued that schizophrenia as a condition came about as a result of natural selection. He has argued that schizophrenia is a by-product of the development of language, resulting from an evolutionary change approximately 150,000 years ago, that persisted due to sexual selection. However, conversely to study in polygenes or multiple allele combinations, he maintains that the answer lies in:   A strand of research into schizophrenia is to investigate the links between viruses that attack the immune system such as herpes and the onset of schizophrenia. Researchers in this field are hopeful that this connection may provide a cure for schizophrenia within the next 20 years. Muller proposes that the vulnerability-stress model of analysis of schizophrenia should become the vulnerability-stress-inflammation model:   Research shows that viral infections of the immune system can dramatically increase the frequency of the onset of schizophrenia.  “ a large scale Danish nationwide study on 39,076 persons with a diagnosis of schizophrenia spectrum disorders showed that the history of hospitalisation with infection increased the risk of schizophrenia by 60%”  In the Netherlands alternative proposals for the name "schizophrenia" include "dysfunctional perception syndrome" and Salience Syndrome :  "The concept of 'salience' has the potential to make the public recognize psychosis as relating to an aspect of human mentation and experience that is universal. It is proposed to introduce, analogous to the functional-descriptive term 'Metabolic syndrome', the diagnosis of 'Salience syndrome' to replace all current diagnostic categories of psychotic disorders. Within Salience syndrome, three subcategories may be identified, based on scientific evidence of relatively valid and specific contrasts, named Salience syndrome with affective expression, Salience syndrome with developmental expression and Salience syndrome not otherwise specified."