Ust-Ishim femur

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The thigh bone of Ust-Ishim is the oldest fossil of an anatomically modern human ( Homo sapiens ), the genome of which has been sequenced and therefore largely reconstructed. The almost completely preserved femur was discovered in western Siberia ( Omsk Oblast , Russia ) and dated to an age of around 45,000 years.

discovery

While searching for the tusks of mammoths , which he used as the raw material for jewelry, the Russian ivory carver Nikolai Peristov discovered a long bone sticking out of the ground north of the village of Ust-Ishim on the left bank of the Siberian Irtysh River . Peristov dug up the find and showed it to a police forensic scientist , who identified the bone as likely human. In fact, the find is a left human thigh bone (femur) whose lower joint attachment has broken off. The find was handed over to the Leipzig- based Max Planck Institute for Evolutionary Anthropology for age determination and examined in Svante Pääbo's group . The Leipzig researchers named the find after the place of its discovery, Ust-Ischim.

Investigation results

Although the exact location could not be reconstructed later, it is certain that the bone was eroded from an alluvial soil , the layers of which are approximately 50,000 to 30,000 years old ( oxygen isotope level 3), but in which much older, Young Pleistocene and Middle Pleistocene fossils are embedded.

Two samples of the bone were taken independently of one another, 890 and 450 milligrams, and an age of 41,400 ± 1,300 years ( BP ) and 41,400 ± 1,400 years (BP) were calculated using the radiocarbon method. Calibrated , this resulted, according to a published study in 2014 an age 46,880 to 43,210 years ago ( cal BP ). In 2020, a new calculation was published for the fossil, which resulted in an age of 45,950 to 42,890 years (cal BP). According to both dates, the Ust-Ishim find is considered to be the oldest remnant of an anatomically modern human outside of Africa and the Middle East that was directly dated using the radiocarbon method . From the ratio of carbon - and nitrogen - isotopes into the bone sample has been derived that the food then mainly of C 3 plants and animals, which C 3 ate plants, was, however, a significant proportion of ingested protein presumably derived from fish.

To determine the DNA , nine samples of 41 to 140 milligrams each were taken. The analysis showed that the bone belonged to a man. A comparison of his genome with DNA samples from more than 50 human populations living today showed, "... that the man from Ust-Ishim is as closely related to people from East Asia as to people who populated Europe during the Stone Age." The investigations also showed that around two percent of the DNA is identical to Neanderthal DNA, which is a comparably large proportion as has been proven for East Asians and Europeans living today. However, the Neanderthal DNA segments of this early anatomically modern human are much longer than those of humans living today, which is explained by the fact that the intermingling with the Neanderthals was not so long ago; due to crossing-over and other causes, the sections shorten in the course of the generation sequence. Based on model calculations, it was estimated that mating with Neanderthals could have taken place around 7,000 to 13,000 years before the man's lifetime, i.e. around 50,000 to 60,000 years ago. Previous model calculations had only limited this period to a relatively broad epoch 37,000 to 86,000 years ago.

The mitochondrial DNA is the in October 2014 in Nature published According to analyzes on the basis of today in Eurasia widespread haplogroup R , the Y chromosome , therefore, is at the base of Haplogroup K (XLT) .

Web links

Individual evidence

  1. ↑ a b Ewen Callaway: Oldest-known human genome sequenced. In: Nature . Volume 514, No. 7523, 2014, p. 413, doi: 10.1038 / 514413a
  2. ↑ Qiaomei Fu et al .: Genome sequence of a 45,000-year-old modern human from western Siberia. In: Nature. Volume 514, No. 7523, 2014, pp. 445–449, doi: 10.1038 / nature13810
  3. ^ Johannes van der Plicht et al .: Recent developments in calibration for archaeological and environmental samples. In: Radiocarbon. Online publication of April 21, 2020, doi: 10.1017 / RDC.2020.22 .
  4. ↑ Genome of the oldest modern human being decoded. Max Planck Society of October 22, 2014