File Name: viruses and the evolution of life .zip
The constant battle between pathogens and their hosts has long been recognized as a key driver of evolution, but until now scientists have not had the tools to look at these patterns globally across species and genomes. In a new study, researchers apply big-data analysis to reveal the full extent of viruses' impact on the evolution of humans and other mammals. Their findings suggest an astonishing 30 percent of all protein adaptations since humans' divergence with chimpanzees have been driven by viruses.
Evolution of viruses
This page has been archived and is no longer updated. The evolutionary history of viruses represents a fascinating, albeit murky, topic for virologists and cell biologists. Because of the great diversity among viruses, biologists have struggled with how to classify these entities and how to relate them to the conventional tree of life. They may represent genetic elements that gained the ability to move between cells. They may represent previously free-living organisms that became parasites. They may be the precursors of life as we know it.
The genetic diversity of viruses is commensurately enormous and might substantially exceed the diversity of cellular organisms. Unlike cellular organisms with their uniform replication-expression scheme, viruses possess either RNA or DNA genomes and exploit all conceivable replication-expression strategies. Although viruses extensively exchange genes with their hosts, there exists a set of viral hallmark genes that are shared by extremely diverse groups of viruses to the exclusion of cellular life forms. Coevolution of viruses and host defense systems is a key aspect in the evolution of both viruses and cells, and viral genes are often recruited for cellular functions. Together with the fundamental inevitability of the emergence of genomic parasites in any evolving replicator system, these multiple lines of evidence reveal the central role of viruses in the entire evolution of life.
Viral evolution is a subfield of evolutionary biology and virology that is specifically concerned with the evolution of viruses. This elevated mutation rate, when combined with natural selection , allows viruses to quickly adapt to changes in their host environment. In addition, most viruses provide many offspring, so any mutated genes can be passed on to many offspring quickly. Viral evolution is an important aspect of the epidemiology of viral diseases such as influenza influenza virus , AIDS HIV , and hepatitis e. The rapidity of viral mutation also causes problems in the development of successful vaccines and antiviral drugs , as resistant mutations often appear within weeks or months after the beginning of a treatment. One of the main theoretical models applied to viral evolution is the quasispecies model , which defines a viral quasispecies as a group of closely related viral strains competing within an environment. Viruses are ancient.
The field of virus evolution has grown sharply in the past five years, partly due to the explosive growth in availability of genomic sequence data, which will continue to grow at an exponential rate over the coming years. Virus evolution is an inter-disciplinary field worked on by scholars from virology, evolutionary biology, epidemiology, ecology, computational biology and genomics and Virus Evolution provides a venue for in-depth discussion on the field of virus evolution. Virus Evolution is a new Open Access journal focusing on the long-term evolution of viruses, viruses as a model system for studying evolutionary processes, viral molecular epidemiology and environmental virology. The aim of the journal is to provide a forum for original research papers, reviews, commentaries and a venue for in-depth discussion on the topics relevant to virus evolution. Oxford University Press is a department of the University of Oxford.
Viruses and cells intertwined since the dawn of evolution
Viral Diseases and Human Evolution. I: , The interaction of man with viral agents was possibly a key factor shaping human evolution, culture and civilization from its outset. Evidence of the effect of disease, since the early stages of human speciation, through pre-historical times to the present suggest that the types of viruses associated with man changed in time. As human populations progressed technologically, they grew in numbers and density.