Extinciones masivas, tipos de virus y evolución animal

Hola, os pego un pedazo de un articulillo de PhysOrg sobre una nueva teoría sobre grandes extinciones, el papel de los virus y el por qué después de las extinciones masivas surge una gran variedad de vida. Me ha resultado muy interesante, por eso lo pego aquí por si quereis dar vuestra opinión. La noticia completa está aquí.

Copio y pego:

“As previous research has shown, the battle between viruses and the cells they try to infect is thought to be a major force in driving evolution. Under pressure from viruses, cells continually develop mutations to avoid infections, but these mutations usually aren’t useful in other ways (except coincidentally). However, as the new model shows, when an extinction event occurs that kills off many of the cells in an environment, the number of viruses also decreases for lack of hosts. The viruses’ main weapon is having a variety of host recognition proteins (HRPs) that know which cells to attack. But fewer viruses means fewer HRPs, so that surviving cells that are immune to the few remaining viruses now have a chance to evolve in an environment free of virus interference. Under virus-free conditions, cells can inherit mutations that are likely to be more useful in the long run, rather than simply defensive strategies. In this way, extinction events speed up the development of new biological functions that might otherwise be unlikely to emerge. Without extinction events, viruses might control all of Earth’s evolution.”

Pringy!