An analysis of traces of ancient DNA from plankton in the sediments of the Black Sea has revealed that the same genetic stocks of virus and algae which remains may persist and coexist for centuries.
The results of this research may have implications for the valuations are made on the degree of ecological importance of viruses in the formation of ocean ecosystems, and perhaps that of freshwater.
Moreover, the finding that DNA viruses and the algae from the remaining can be preserved in the geologic record is of great interest to microbial ecologists, such as value Marco Coolen of Oceanographic Institution in Woods Hole, United States. Having that information in the geological record provides unprecedented insight into the long-term population dynamics of algae and viruses, separately and jointly.
Viruses are known to play an important role in population dynamics of phytoplankton in the oceans today. This new research indicates that this was also true for thousands of years ago.
When examining a genetic record of 7,000 continuous years if stored in sediments under the Black Sea, Coolen found that both the DNA of a virus called Coccolithovirus, like the kind of phytoplankton that remains (Emiliania huxleyi), have been preserved for thousands years.
This species of phytoplankton plays an important role in the global carbon cycle.
Biologists now have a perspective of several millennia of the dynamics between virus-carrying organisms in the ocean. The lab work done before such coexistence confirmed but limited to a few successive years, which gave him the record available.
The records of many years on organisms and their viruses, as studied by Coolen and Benjamin van Mooy, could answer such important questions as: What factors are involved in controlling viral infections important marine algae world and how long they can coexist on the same stocks of algae and viruses? Were the ancient populations of algae controlled only by the prevailing environmental conditions, or viruses also played an important role?
This last question is of particular interest because there are little long-term records of the virus. Ecological changes that occurred in the past in the communities of algae are usually explained by changes in climate and environmental conditions.
Now it seems likely that viruses also play a role.
It is not a trivial matter when the species on which it acts such as a virus consumes carbon dioxide, as does E. huxleyi, which carries out photosynthesis the same way as plants. If the virus kills more phytoplankton, this results in a net increase in emissions of greenhouse gases.