A fossil skull which was dug up along a river in Harbin, China raised multiple questions related to the human lineage as the skull was once part of a member belonging to a Homo species. This much shocking discovery has made facts and findings that was long considered the most accurate till date to be rethought and reanalyzed as this new species could now potentially replace the Neanderthals, Homo neanderthalensis, which is determined as our most recent ancestor. Nicknamed as the “Dragon Man”, the individual to whom this skull once belonged may very well be a member of a new Homo species.
Dubbed as Homo Longi, paleoanthropologists suggest that this particular individual to whom the skull belonged, would have lived at least 146,000 years ago. Due to the time period that this individual supposedly walked Earth, they consider that his species emerged during the Stone Age. The shape of the skull, probably had a large brain situated on top, a relatively short face with small cheek bones, resembles a trait that is very much like ours. It also showed that the species had a long yet relatively low braincase, thick brow ridges, large molars and almost square eye sockets. These traits however are more similar to older Homo species such as the Neanderthals and the Denisovans. H. longi could actually be an intermediary link in the evolutionary path between Homo sapiens and the much older species.
It is well known that during the Mid-Pleistocene Epoch (770,000 to 126,000 years), many groups of the Homo Genus actively travelled within Africa, Asia and Europe. These travels often resulted in the intermingling of two different Homo species which sometimes ended in the interbreeding of these species but many offspring that were produced during such circumstances hardly survived, some just lived long enough to pass on their genes to consecutive generations. It is quite possible that members of H. longi interbred with early H. sapiens ancestors that were also the descendants of the Neanderthals. Especially given surprising factors such as having similar traits to both a much older species (the Neanderthals) and also a much younger species (us Humans), this interbreeding scenario is quite possibly true. Thus potentially negating the role, closest relative from the Neanderthals.
The researchers estimated the species’ contribution to human evolution by comparing the skull with other Homo fossils from Africa, Asia and Europe. These comparisons indicated that H. longi once shared a common ancestor with H. sapiens roughly around 949,000 years ago. This was the surprising shock that waivered a once proven fact which considered the Neanderthals as our closest relative. The common ancestor of both the Neanderthals and us, the H. sapiens was long dated to have lived just over 1 million years ago and researchers think H. longi would be our closest possible relative due to it having a slightly closer evolutionary link to us than what the Neanderthals did.
However not all researchers agree with these speculations. Despite having many factors that lead to H. longi being our potential closest relative, many still think that the title should still belong to the Neanderthals. The researchers that oppose the idea of H. longi being our closest relative say that the reason this newly found “species” carries similar traits to both the Neanderthals and the humans is due to the interbreeding of different Homo groups. However, they do not believe such unions resulted in an entirely new species.
Other than Neanderthals and Denisovans, there were also other homo species that thrived in our surrounding regions such as H. erectus in Java, Indonesia, H. floresiensis in Flores and H. luzonensis in Luzon Island. This could have led to the formation of many populations due to the greater admixture in the gene pool. One of the major factors of speciation is isolation as a group of interbreeding organisms have the time and space to exchange genetic information with one another without the interference of other closely related groups. Overtime, gradual accumulation of small genetic changes exclusive to the subpopulation results in them becoming a new species. Though Dragon Man and his brethren had similar genetic differences, it is quite possible that they never had any sort of isolation long enough to form a new species. So, the declaration of the Dragon Man’s species being our closest ancestors or them being a new species at all may take much longer and quite possibly never happen.
Note: Arrivin Mutiran is a Biotechnology undergraduate student from International University of Malaya-Wales. With an ardent passion for conservation and sustainability he found his calling for science communication during his internship with The Petri Dish.