Eukaryotes—the building blocks of complex life—appeared on Earth 1.7 billion years ago, and now scientists have solved a ...

Our single-celled ancestor lived in a world without plants, animals or oxygen-rich oceans. Yet, this seemingly simple microorganism took the first steps toward complex life. From this ancestor emerged ...

Complex cells are thought to be the result of a union between two ancient microorganisms, but scientists have long been stumped over how this unlikely pair came together.

A team led by researchers at the University of Texas at Austin has produced what may be the strongest evidence yet that the ...

Ancient microbes tied to our earliest ancestors could use oxygen, reshaping ideas about how complex life began on Earth.

A microscopic creature from a boiling hot spring in Northern California has just reset the upper limit for how hot complex life can run. The newly described “fire amoeba” thrives at temperatures that ...

A recent study by the University of Bonn and University Hospital Bonn and the University of Freiburg shows that the ...

A giant virus discovered in Japan is adding fuel to the provocative idea that viruses helped create complex life. Named ushikuvirus, it infects amoebae and shows unique traits that connect different ...

In the oceans and on land, scientists are discovering rare, transitional organisms that bridge the gap between Earth’s simplest cells and today’s complex ones. By Carl Zimmer A flurry of new studies ...