An article published in the journal “Molecular Biology and Evolution” describes a research that from a protein in human saliva showed that there were interbreedings between Homo sapiens and another unknown hominin species. A team of scientists conducted a study on the gene called MUC7, which encodes a mucin, a protein that determines some of the characteristics of human saliva and tracing its history found traces of these ancient interbreedings between hominins in Sub-Saharan Africa.