Discovery of oldest human DNA in Spanish cave tangles human family tree

[muriel_volestrangler]

Meyer's team dated the bone fragments to 400,000 years old, but further analysis left them baffled. The mitochondrial DNA did not match that of Neanderthals, but was closer to a sister group called the Denisovans that lived in Siberia. Details of the study appear in the journal Nature.

Meyer says there are a number of explanations, but admits more work is needed. One possibility is that an older lineage of human ancestors, perhaps Homo erectus, bred with the ancestors of the Sima de la Huesos individuals, and passed on their mitochondria. But several other explanations are being explored by anthropologists.

"Either way, this new finding can help us start to disentangle the relationships of the various human groups known from the last 600,000 years," said Chris Stringer, head of human origins at the Natural History Museum in London. "If more mitochondrial DNA can be recovered from the Sima population of fossils, it may demonstrate how these individuals were related to each other, and how varied their population was."

Meyer said the Leipzig group now hopes to extract so-called nuclear DNA from the Sima fossils, which contains more information but will be much harder to extract because there is far less material.

http://www.theguardian.com/science/2013/dec/04/oldest-human-dna-discovered-spanish-cave

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 Holocene. 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.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12788.html

[Jackpine Radical]

1. The breakthroughs in this paleo-DNA field are coming at an amazing pace.

I just abandoned reading a book on the topic from 2007 because I realized half the information in it had been superseded by more recent findings.

I'm particularly fascinated by the recent finding of Neanderthal DNA suggesting that they had a specific gene form that is associated with the presence of language.

[libodem]

2. I'm with you

On finding this very interesting.

[AlbertCat]

3. Is this before or after....

.... the Great Flood, or Tower of Bable?

[Spitfire of ATJ]

4. Easy. Migration over the top of the world during the ice age.

[muriel_volestrangler]

5. It's not a problem of how they got there; but it's a new time for Denisovans

Until now, they were known from DNA from about 41,000 years ago in the Altai Mountains, Siberia.

https://en.wikipedia.org/wiki/Denisova_hominin

Spain and Siberia can be walked between, in or outside an ice age. This was well before they'd been detected, until now. Also, traces of Denisovan DNA have been found in people from Melanesia and south east Asia, but not Europeans, as far as I can see. This widens their range dramatically.

[Spitfire of ATJ]

6. You don't populate a planet by being homebodies.

[Enthusiast]

7. The human ancestor fossil record is too incomplete and unreliable

to be of much use in answering major questions about human evolution.

Sure we can tinker around the edges but we cannot answer much if we rely on such a scant fossil record.

DNA is entirely different. With DNA we could potentially answer the big questions.

The problem has always been that we assumed too much from such a very few fossils.