The History of Our Tribe Hominini Textbook Part IV Pleistocene Epoch Chapter 34 The Denisovans

34 . The THE A New Species of SITE and Caves in the Mountains of Russia PEOPLE Michael and Anatoly Figure Cave ( approximate location indicated by arrow ) Russia relief location map by is licensed under . INTRODUCTION In 2008 , Russian scientists Michael ( paleontologist ) and Anatoly ( archaeologist ) covered a terminal finger phalanx from a young girl , dubbed , in the Cave in the Mountains of Russia ( see Figures and ) The , as they have come to be called , inhabited the cave by 50 kya . 204

PHYLOGENY The phalanx was sequenced by lab at the Max Planck Institute , where it was determined to be from a new form of extinct . Its ancestor is thought to have split from our own lineage by 800 kya , subsequently splitting into the and lineages ( 2013 ) The two resulting lineages remained as alike as two geographically distant modern human . 2014 ) uses the example of and the San people of South Africa . It is estimated that gene flow from to was fairly low ( 205 ) and seemingly occurred only locally in the region ( et al . 2013 ) What is even more interesting from our perspective is that seem to have with the first wave of as they passed through southern Asia after leaving Africa . These humans already carried genes from having with them . Thus modern human that have descended from those early humans ( indigenous , Polynesians , Australians , and some Filipinos ) carry genes , along with the mean of genes that all possess , meaning that a total of of their genes are derived from extinct ! Genes for dark skin , hair , and eyes were present in the genome and are present in modern ( Marshall 2013 ) This is fascinating from two perspectives . First , it is interesting that those ancestral survived in a modern population . Second , we now know something about what the likely looked like . Wow ! The genes that the rest of possess may have been inherited from , due to their close genetic relationship with the . It is of great interest that the genetic variability in one of our important immunological systems , the human leucocyte antigen ( system , is probably due to interbreeding with . Half of the variant genes , termed alleles , seen in Eurasian populations are derived from those two extinct species ( et al . 2011 ) What is fascinating is that those alleles likely conferred a selective advantage on some of our ancestors , and they thus survived in their . It is likely that and inherited the allele ( from , lending support for the latter species having diverged from our lineage prior to the mutation ( that led to the forms present in the former two species . Finally , a variant of the gene in Tibetans has also been traced to the . The allele is an to the hypoxic ( ie . low oxygen ) conditions of high altitude . The allele affords those individuals with better oxygen metabolism capabilities ( et al . 2014 ) Mitochondrial DNA ( from a 400 kya femur from the Sima de los site in Spain has been found to most closely resemble ( 2013 ) The site contains Homo material , and if the leg bone is from an individual of that species , it will further muddy the phylogenetic waters . However , it must be remembered that gives only maternal lineage information , and it is thus possible that the individual was not more closely related to but that the alleles were conserved in his or her lineage . DISCOVERY AND GEOGRAPHIC RANGE In addition to Cave , and also found bone fragments in the nearby Cave . They have since recovered two teeth and a toe bone . The caves were also occupied by and humans at various times over the millennia . Prior to the discovery of in the area , it was thought that they ranged no farther east than . This new discovery extends their geographic range by . The also must have had a large graphic range , since they are thought to have bred with as they passed through southern Asia ( see Figure ) It is amazing that for over 100 years , the only extinct that we knew of in the northern hemisphere were the and and now , in just the last couple of years , we have two more , the and the Red Deer Cave . 2014 , unless otherwise indicated . 34 . The 205

' Figure Cave . by at is licensed under . Cave Key Maximum Sea Level during the Ice Age modern Homo sapiens years ago erectus years ago Europe Figure Possible routes taken by Late . Spread and evolution of by John Croft at English is licensed under . PHYSICAL CHARACTERISTICS While there is not much to go on , the finger bone was broad and robust relative to modern humans and the molars were large with widely diverging roots , unlike the little or no space between molar roots . The robusticity of the phalanges suggests that the may have been morphologically similar to ( Reich et al . 2010 ) 206 The History of Our Tribe

ENVIRONMENT AND WAY OF LIFE The environment of the area must have been at least seasonally cold . Mountains surrounding the area were covered with glacial ice during the Late ( et al . 2011 ) However , it is possible that game may have been available in the lower elevations . If large game migrated seasonally , then the would have followed and thus would have only resided in the area when animals were on their northern grazing and birthing grounds . Since was cognitively and culturally advanced , the were descended from them , and with in the region at some point ( in time , it is likely that they all had similar behavior and culture . While complex tools and an ivory bracelet were found , it is not known whether they are attributable to the . They are more likely artifacts , as they are usually only found at sites . 34 . The 207