Danish teacher sows doubts about earlier discoveries of traces of the world's oldest life

Researchers believe they have found traces in the Isua Strait near Nuuk in southwestern Greenland.

But there are major disagreements about discovery.

"It's important to clarify what's going on before we know it's a matter of life, otherwise we risk finding false traces on Mars," says Minik Rosing, professor at the National Museum of Natural History. from Sweden and one of the researchers behind a study, which just appeared in the journal Nature.

It's no coincidence that he mentions Mars, as the first author of the new study, Abigail Allwood, is employed by NASA's Jet Propulsion Lab.

Traces of algae and bacteria

In 2016, an international research group described a sensational discovery. They had found stromatolites in Greenland stones 3.7 billion years old, the oldest traces of life.

Stromatolites are distinctive structures that algae and bacteria can form in minerals. When the algae are in the mud of the seabed and mineral dust covers them, they grow through the top layer several times to promote photosynthesis.

For a long time, they form a layered structure in sediments, which can be seen as cones that cross the layers. When stromatolite descends into the soil over time, the structure is encapsulated in stone due to pressure and heat.

And in 2016, the research group, led by Professor Allen P. Nutman of Wollongong University in Australia, could present the results of a fossil stromatolite preserved after 3.7 billion years in a stone found in Isua.

Stromatolites or not

This discovery caused the blocking of the eyes of many researchers. One of them was Minik Rosing, who, along with Abigail Allwood of NASA, returned to Isua to check the results.

The analyzes come