Bush of life: role of giant viruses in food web (Introduction)

by David Turell , Friday, April 17, 2020, 15:30 (1680 days ago) @ David Turell

They live on ocean forms at the bottom of the web:

https://www.sciencemag.org/news/2020/04/giant-viruses-aren-t-alive-so-why-have-they-sto...

Viruses might not be alive, but they may be altering life on a global scale. Researchers have found that a bizarre group of microbes known as “giant viruses” contain genes associated with metabolism, which they likely use to convert their zombified hosts into supercharged energy factories. Because many of their victims are important players in dampening climate change and in controlling ocean ecosystems, the megaviruses may be exerting an unexpected power over life on Earth.

There are more than 200,000 kinds of viruses in the world’s oceans. Some are giant viruses, so named because they tend to be about 10 times bigger than the average virus. They’re still tiny—the largest is only one-fifth the size of a red blood cell—which may explain why they went undiscovered until 2003. Since then, researchers have learned some basic facts—the viruses mostly infect amoebas and phytoplankton, for example—but scientists are still trying to figure out what makes them tick.

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Their results, published this month in Nature Communications, show that giant viruses are extremely diverse, splitting into 54 distinct groups. Several genomes were new to science and likely represent new species.

In addition to the usual genes that allow a virus to infect its host and multiply, many also contained genes for metabolism, the process that converts food into energy in all living cells. This was a surprise because viruses don’t eat. And strangely, these genes weren’t a recent addition, says first author Mohammad “Monir” Moniruzzaman: Many had been evolving in the viruses for millions of years. “If your goal is simply to find a new host and multiply,” he asks, why do you need these genes?

All of this could have a dramatic impact on sea life. Phytoplankton suck the greenhouse gas carbon dioxide from the atmosphere as they photosynthesize. They also form the base of the entire food web, the interconnected “who-eats-whom” relationships between predator and prey. Still, researchers are just beginning to study what the larger impacts could be. (my bold)

Frederik Schulz, a microbiologist at the Joint Genome Institute, says the new work comes to “similar conclusions” as those found by his own team. But he cautions against speculating too broadly. Just because a gene helps living organisms metabolize, doesn’t mean it does the same thing for viruses.

Comment: Since these viruses are part of the lowest sections of the sea food web, and affect phytoplankton photosynthesis, using CO2 and producing free O2., it can be proposed they are a significant part of God's design plan.