|15 April 2014
Prehistoric DNA paints more complex picture of human evolution
According to Dr Mike Bunce, a researcher at Curtin University's Trace and Environmental DNA Laboratory, the ability to look deeper into fossils - past the traditional methods of simply carbon-dating fossils and determining their morphology - represents a whole new level of specificity in collecting quantifiable data that will lead to more conclusive findings about human and animal evolution.
Interestingly, these new findings about the long history of human genetics are not necessarily lining up with previously held notions of human evolution. Science writer Annie Hastwell points out several examples, such as a 400,000 year old femur that was found in the Pit of Bones in the Atapuerca caves in Northern Spain, which was recently analyzed using DNA sequencing techniques: "Rather than the Neanderthal origins scientists expected to find in the DNA, they found evidence that the most recently identified hominid, the mysterious Denisovan, previously thought to be confined to Siberia and Australasia, had at some stage interbred with the European Neanderthals."
A similar finding came from a DNA-based look into Homo Floresiensis, another early humanoid race that are sometimes referred to as "Hobbits" due to their marked small stature. Originally discovered in Indonesia, Homo Floresiensis were inexplicably able to migrate over the Wallace Line near Borneo. Subtle genetic variations in ancient remains are fracturing the more simplified, traditional view.
There are still limitations to the genetic sequencing approach to piecing together human evolution. The sequencing process often reveals results that are disembodied from the fossils themselves. Researcher Wolfgang Haak from the Australian Centre for DNA explains that the actual collection of bones is not as complete as the genetic information: "We have the full Denisovan genome but no skeleton, just a finger bone, and then in Spain we have those fossils that are Neanderthals but genetically they look like the Denisovans but we can't compare because we don't have a Denisovan fossil. Then in Flores we have a perfect Hobbit skeleton but no DNA." Because of this, work still needs to be done to reconcile DNA results with actual fossils.
DNA sequencing of ancient human remains shows how different races interbred, migrated, influenced one another, and were influenced, shaping our understanding of the immensely complex process that led to modern humanity.
Edited BioNews Texas (25 March 2014)
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