A team of researchers have said that certain 'Genetic switches' caused the between Neanderthals and modern humans.

The study showed that some genetics switches were to blame for the key differences between Neanderthals and modern humans as these switches controlled the phenotypic expression of certain genes in the body. The study into human evolutionary biology was led by Hebrew University of Jerusalem geneticist Liram Carmel and compared DNA extracted from a Neanderthal and a modern human.

The team also studied DNA from an extinct human species called, Denisovan that lived in the Eurasia during the Stone Age in order to teach its conclusion derive this conclusion. Researchers wanted to determine the key reason for the difference because two 99.8 percent of the DNA of the two species were the same.

"Ancient DNA sequencing has recently provided high-coverage archaic human genomes. However, the evolution of epigenetic regulation along the human lineage remains largely unexplored. We reconstructed the full DNA methylation maps of the Neanderthal and the Denisovan by harnessing the natural degradation processes of methylated and unmethylatedcytosines," said the study.

The also pointed out that differences in brain size and development were controlled by genetic switches.