(CNN) - Apparently, there's a bit of Neanderthal in many of us, according to a newly released study.

Research says modern humans of non-African heritage have distant genetic ties to Neanderthals - cousins of modern humans who went extinct 30,000 years ago.

Published in Oxford Journals' "Molecular Biology and Evolution," the study backs up previous theories that humans and Neanderthals mated and had offspring.

The research is based on analysis of more than 6,000 DNA samples gathered from all populated continents.

In most of the samples, part of the human X chromosome called the haplotype shared a DNA sequence with the Neanderthal genome, said University of Montreal Professor Damian Labuta, who lead the study for CHU Sainte-Justine Research Center. But the Neanderthal sequence was not present in haplotype taken from people with sub-Saharan African heritage.

Neanderthals lived in what is now western Eur-Asia including parts of Germany, France, Spain, Russia and Croatia. Their ancestors left Africa at least 400,000 years ago, which likely explains why humans with African heritage don't have Neanderthal-linked chromosomes.

So is sharing DNA with Neanderthals a good thing?

Neanderthals: Less creative than us?

Possibly, said Labuta. The mixing of genetic material between humans and Neanderthals 50,000 years ago may have helped modern day humans ward off dangerous diseases, funguses or viruses.

"Diversity is very important for long-term survival of a species," Labuda said on the phone from his Montreal office. "Whether this diversity in this case was useful, we don't know yet."

More study has to be done to find out if the genetic material gained from Neanderthals is simply "junk DNA" or served a useful purpose, he said.

Study: Neanderthals cooked, ate veggies

Popular culture hasn't been kind to our ancient cousins, leading to the misperception that Neanderthals weren't intelligent. In fact, experts believe they were just as smart as modern humans.