A new study has suggested that Neanderthals, along with our other evolutionary cousins, may have been killed off because of cold, dry weather when climate change occurred 40,000 years ago.

According to Phys.org, the gradual shift to a much colder climate also happens to have coincided with the demise of Neanderthals in different parts of Europe, in a sad twist of fate that eventually spread to other regions. With this came the permanent rise of Homo sapiens.

As Michael Staubwasser of the University of Cologne in Germany explained, “Whether they moved or died out, we can’t tell.”

Neanderthals once flourished in Asia and Europe, yet eventually died just a few thousand years after Homo sapiens appeared on the scene. There has been much speculation over the years as to the cause of the disappearance of Neanderthals, and while mass epidemics and rivalry with Homo sapiens and other species has been suggested, the shift to a much colder and drier climate may have also had a major and lasting effect on Neanderthals.

In their new study, scientists analyzed data that was taken from two periods in which cold and dry weather was prevalent. The first of these spells occurred 44,000 years ago and lasted for a full thousand years. The second episode of climate change happened 40,800 years ago and kept going for 600 years.

Interestingly, researchers also found that it was during these times that tools and ancient artifacts from Neanderthals began to slowly disappear from areas in France and the Danube River valley, only to be replaced by items from Homo sapiens.

One of the major effects of climate change for Neanderthals would have been that they would have noticed their once vast forests slowly giving way to grasslands filled with shrubs. As Homo sapiens may have been more used to these grasslands, it would have given them a major advantage over Neanderthals.

Katerina Harvati, who studies the lives of Neanderthals at the University of Tuebingen in Germany, has stated that while it is indeed very useful to have new data of the climate change that would have occurred in southeast Europe, it is also impossible to conclusively know whether the cold and dry weather would have been the main thing that was responsible for killing off Neanderthals, especially as there is limited data available in the new study, all of which is still up for debate.

The Smithsonian’s Rick Potts has called the new research “a refreshing new look,” at the demise of Neanderthals.

“As has been said before, our species didn’t outsmart the Neanderthals. We simply outsurvived them. The new paper offers much to contemplate about how it occurred.”

The new study which suggests that Neanderthals may have died off because of climate change has been published in PNAS.