Myalla and her joey, Arru, are two of the koalas whose DNA was sequenced for the project. Photo: San Diego Zoo Wildlife Alliance. The San Diego Zoo cares for the largest population of koalas outside ...

Today’s column continues the theme of plant viruses introduced in this column last week. A virus can reduce a plant’s growth, lower its yield and result in inferior fruit, vegetables and flowers.

“It’s the most bizarre thing,” Edward Holmes, a virologist at the University of Sydney, told NPR’s Goats and Soda. “If you compare it to the human body, it’s like a person would have their legs, trunk ...

The original version of this story appeared in Quanta Magazine. Ever since viruses came to light in the late 1800s, scientists have set them apart from the rest of life. Viruses were far smaller than ...