God's Natures wonder: Cell conducts anti-viral warfare (Introduction)

by David Turell , Sunday, November 06, 2016, 15:15 (2937 days ago) @ dhw

DAVID: The point I'm making is at the starting point of this species. The first individuals with this capacity die in the process of defending themselves. How do the dead pass on the ability, if dying in the process of defense? The origin of this species must involve a large number of individuals at the start, all with this ability to explain the start. Some are attacked and die. Others then survive and reproduce. This speciation must be a saltation.

I don’t understand why the species has to begin with this capacity. As I understand it, the process would have begun when some existing Cafeteria were first attacked by the CroVs. It’s not the origin of a species but the origin of a means of countering an enemy:

QUOTE: And Cafeteria has evolved to exploit the concept that the enemy of my enemy is my friend. Rather than waiting for maviruses to arrive by chance when CroVs attack, it actually carries the genes that code for mavirus inside its own genome.

These genes are usually dormant, but they get turned on when Cafeteria is invaded by CroV. “It acts as an inducible antiviral defence system,” write Fischer and his colleague Thomas Hackl in a new preprint paper.

The infected Cafeteria cell still dies – but when it breaks apart it releases maviruses rather than CroVs, preventing the spread of the infection. This, then, is altruistic behaviour, which turns out to be surprisingly common among microbes. For instance, some bacteria kill themselves as soon as they are infected by viruses to prevent the infection spreading.

dhw:Isn’t this just a very original form of immunisation? When CroV strikes, the dormant mavirus gene is turned on, and although the individual dies, this prevents the spread of infection to other individuals. Why would this have required a new species? Surely all mechanisms for immunity help to preserve a species, not create one.

I've explained my concept of new species in my entry today on Wolfe: Sunday, November 06, 2016, 14:57. You are again thinking of the Darwin approach of a tiny number of new individuals starting a new species, I think it is a God saltation of many new individuals.