Mysterious "ghosts" have been discovered in the modern human genome.
Scientists at the University of California, Berkeley, have found DNA fragments from two unknown ancestors in the genomes of modern humans. This discovery is described in a paper published in Science, according to RBC-Ukraine.
How were traces of unknown human ancestors discovered?
It was previously believed that the ancestors of Homo sapiens interacted only with Neanderthals and Denisovans. However, scientists have developed a new method called TRACE (TRacking Archaic Contributions via ARG Estimation), which allows them to analyze genealogical links in the DNA of hundreds of modern humans and reconstruct ancestral lineages without using fossil remains. It is this method that has refuted the established theory.
The study showed that about 2 percent of the modern human genome is derived from ancient hominids. To identify these regions, scientists constructed a phylogenetic recombination graph that maps DNA relationships over time.
Phylogenetic Analysis and Its Results
The timeline illustrates four specific instances (marked by colored arrows) of interbreeding between archaic hominids and early members of the species Homo sapiens. The dates were determined based on a phylogenetic analysis of modern human genomes using the TRACE method (diagram: Yulin Zhang and Priya Murjani/University of California, Berkeley).
“We were actually able to identify and map genomic loci in modern humans that originate from this ‘ghost lineage’ and show that this genetic heritage is present in everyone,” the scientists note.
