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DNA is the genetic code for most of life, including our species of humans, the homo sapiens. Did you know that there were many species of humans before us too, such as our predecessors, the Neandrathals and, who, two hundred thousand years ago, thrived in the Southeast Asian territories of Australia, Indonesia, and Papua New Guinea. Now, meet their closest living descendents, the Ayta Magbukon, a tribe of native Phillipinos, with one-twentieth of their DNA directly from Denisovans!
The most interesting question is why the Ayta Magbukon share the most genetic similarity of any homo sapiens alive, when they are indigeneous to the Philippines, which is nearly two thousand miles away from the location of the most Denisovan fossils. The population living in the hypothesized mainland (namely the Papua New Guinea Highlanders and Australian Aboriginals) are in a distant second place, showing thirty to forty percent less Denisovan ancestry than the Ayta Magubukon. While no strong theory has been formed yet, scientists are wondering if the answer has been hiding in plain sight all along, due to a wide misunderstanding of the physiological form of our ancestors. As it turns out, only a handful of Denisovan fossils have been found, and the vast majority of such fossils were located near Australia. However, numerous remnants of other hominid-like individuals have been found in the Philippines, but, bearing little physical resemblance to Denisovans, have been categorized as members of a new and rare species called homo luzonensis. Putting the pieces together, scientists are now questioning whether the two are actually the same.
The fundamental principle on which this theory stands is geographic isolation; it would have been difficult and impractical for the Denisovans to travel thousands of miles through the rugged ocean to reach another island. If one small group happened to do so, however, they would have to learn to survive on an island with different physical conditions, and any individuals with physiological structures suited for such an environment would be selected for, over time. While interbreeding would maintain mostly the same genetic sequences as the original Denisovans, the appearances of the isolated crew’s descendants would slowly but surely begin to change, in a manner similar to Darwin’s finches. Many scientists are skeptical of the theory, citing the narrow time frame for evolution rendering it impossible to generate numerous necessary adaptations. Finding more fossils, and undergoing a lot of testing, will be necessary before the current hypothesis can be validated, but in the meantime, it remains fascinating to think about how future technology will discover the unknown secrets of the deep past.
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