Denisovans, Another “Grandparent”

In previous articles we have discussed our connection to Neanderthals and how their public image, little by little, is improving. If you follow the news you will have heard a lot recently about a new member of our human family. Today we are going to introduce you to that new ancestor of ours, the Denisovans.

Denisovan Cave Entrance Siberia
Denisova Cave, Siberia

In a remote part of Siberia, the Denisova Cave, in the Altai mountains, remains of human habitation going back thousands of years was discovered. Since the initial discovery, research has continued right up to present day. The first amazing discovery that the cave yielded was the finger bone of a child, later determined to probably be female, her mtDNA was distinctly different from modern man and Neanderthal, however it also revealed that a common ancient ancestor was shared with Neanderthal.

More recent finds revealed not only interbreeding between Neanderthal and Denisovans, but also included an unknown human ancestor as well. Based on finds, it appears that the cave has provided shelter to hominins for more than 250,000 years, including the 18th century Russian hermit, known as Denis, whose use of the cave rendered his being the namesake. The cave appears to have been used by Neanderthals and Denisovans separately, as well as, co-habitation between them over the course of time as well.

Denisovan Cave Siberia
via Nature (IAET SB RAS)  

Right now it is the belief that Denisovans died out before Neanderthal, however, our knowledge of the species is very minimal at present. Originally, we thought that they were limited in habitation to Asia and the Pacific, even some indigenous peoples have up to 6% Denisovan DNA left in their genes. But, recently, the DNA profile of 400,000YO remains in Spain showed greater connection to Denisovans than Neanderthals, surprising researchers who expected connections to Neanderthal but not Denisovans. These remains are being used to speculate that Denisovans and Neanderthals shared a common ancestor from which both species descend from on their own separate evolutionary paths. Of course, much more evidence and research would have to be conducted before any theory could be considered more than speculation.

Thilo Parg / Wikimedia Commons 

One of the more unique inheritances that modern humans have received from our Denisovan ancestors is found among the peoples of the Himalayas. It is a gene that allows them to live normally at the very high altitudes with the thin, low-oxygen air. This knowledge will hopefully led to more field work looking for more dwelling places and remains in higher elevations. Another feature of our Denisovan ancestors that while might seem unique, is not quite as unique as textbook human evolution would have us believe. We did not start out as little 3ft monkey-less apes and steadily and slowly evolve into our 6ft selves. We are not the tallest we have ever been, all our ancestors were not shorter than us. And Denisovans, along with homo heiledbergensis, were taller than at least their Neanderthal counterparts, with Denisovans being probably as robust as their Neanderthal cousins. While some homo heiledbergensis were at least 6ft tall, there are some opinions that Denisovans may have easily been over 6ft. Again, there needs to be more finds made and researched before true theories can be successfully floated in the evolutionary sea.

These recent finds, should remind us all that we truly do know very little about our story and that it is not a simple tale that can be wrapped up in a nice neat pretty little liner package. All one should need to do to know that the story of humanity is more like a web or bush than a one way flowchart is look around at school, at the office, at the market, at the cafe as see all the diversity before your own eyes. Just think of how many unknown stories are before you eyes everyday and then ask how can we think that we have any real idea about all those stories from our whole history!