This is such an exciting time (albeit frustrating) to be a researcher into human evolution.
Scientists have found the oldest DNA evidence yet of humans’ biological history. But instead of neatly clarifying human evolution, the finding is adding new mysteries.
In a paper in the journal Nature, scientists reported Wednesday that they had retrieved ancient human DNA from a fossil dating back about 400,000 years, shattering the previous record of 100,000 years.
The fossil, a thigh bone found in Spain, had previously seemed to many experts to belong to a forerunner of Neanderthals. But its DNA tells a very different story. It most closely resembles DNA from an enigmatic lineage of humans known as Denisovans. Until now, Denisovans were known only from DNA retrieved from 80,000-year-old remains in Siberia, 4,000 miles east of where the new DNA was found.
The discovery is a surprise and forces scientists to rethink the complexity of human evolution of the past hundred thousands of years. The new evidence that has been forthcoming recently strongly suggests human evolution is a very branchy bush with likely more human populations yet to find (all extinct).
This is a straight science story but it’s worthwhile to cover here, I think. Basically, that’s because I’m cynical and I think findings that are so powerful and awesome will get warped and abused by pseudoscientists and anti-science interests, including the religiously inclined. So, let me state this plainly for everyone:
This IN NO WAY means is that evolution is “wrong”. Evolution is a framework for understanding. This new data still fits into that framework, just makes the innards looks far more complicated. We know evolution happens. It’s the way nature works but to figure out the details of how it works is tricky. We are developing ways to tease out the answers or, in this case, to open a new door to lots more questions. The puzzle pieces just multiplied.
This also does not have anything to do with the Bible or aliens or Bigfoot or any other cryptid. I just thought I would make that clear because I suspect people are going to try and wedge it into their favorite outrageous concepts. This is science at work. As our technology has gotten better, we can look even deeper and more carefully into these issues.
Here is a link to the paper (by subscription only) A mitochondrial genome sequence of a hominin from Sima de los Huesos : Nature : Nature Publishing Group.
Excavations of a complex of caves in the Sierra de Atapuerca in northern Spain have unearthed hominin fossils that range in age from the early Pleistocene to the Holocene1. One of these sites, the ‘Sima de los Huesos’ (‘pit of bones’), has yielded the world’s largest assemblage of Middle Pleistocene hominin fossils, consisting of at least 28 individuals dated to over 300,000 years ago. The skeletal remains share a number of morphological features with fossils classified as Homo heidelbergensis and also display distinct Neanderthal-derived traits. Here we determine an almost complete mitochondrial genome sequence of a hominin from Sima de los Huesos and show that it is closely related to the lineage leading to mitochondrial genomes of Denisovans, an eastern Eurasian sister group to Neanderthals. Our results pave the way for DNA research on hominins from the Middle Pleistocene.
I love science.