C*********X
发帖数: 10518 | 2 谢谢。这个有意思。
Ancient Egyptians were an archaeologist's dream. They left behind intricate
coffins, massive pyramids and gorgeous hieroglyphs, the pictorial writing
code cracked in 1799. Egyptians recorded tales of royalty and gods. They
jotted down life's miscellanies, too, as humdrum as beer recipes and doctor'
s notes.
But there was one persistent hole in ancient Egyptian identity: their
chromosomes. Cool, dry permafrost can preserve prehistoric DNA like a
natural freezer, but Egypt is a gene incinerator. The region is hot. Within
the mummies' tombs, where scientists would hope to find genetic samples,
humidity wrecked their DNA. What's more, soda ash and other chemicals used
by Egyptian embalmers damaged genetic material.
A study led by researchers at the Max Planck Institute for the Science of
Human History and the University of Tubingen in Germany managed to plug some
of those genetic gaps. Researchers wrung genetic material from 151 Egyptian
mummies, radiocarbon dated between Egypt's New Kingdom (the oldest at 1388
B.C.) to the Roman Period (the youngest at 426 A.D.), as reported Tuesday
in the journal Nature Communications.
Johannes Krause, a University of Tubingen paleogeneticist and an author of
the study, said the major finding was that “for 1,300 years, we see
complete genetic continuity.” Despite repeated conquests of Egypt, by
Alexander the Great, Greeks, Romans, Arabs and Assyrians — the list goes on
— ancient Egyptians showed little genetic change. “The other big surprise
,” Krause said, “was we didn't find much sub-Saharan African ancestry.”
The remains came from Abusir el-Meleq, an ancient Nile community in the
middle of Egypt. From the mummies the scientists extracted bone, teeth and
soft tissue samples. (Although Egyptian embalmers removed the brains of the
deceased, the scientists wrote that “in most cases, non-macerated mummy
heads still have much of their soft tissue preserved.”)
The hard samples yielded the most DNA, perhaps because the teeth and bones
were protected by soft tissue or because the embalming processes left
tougher material intact. After preparing the samples in a sterilized room in
Germany, the researchers bathed the samples in UV radiation for an hour to
minimize contamination.
Ancient Egyptians were closely related to people who lived along the eastern
Mediterranean, the analysis showed. They also shared genetic material with
residents of the Turkish peninsula at the time and Europe.
Given Egypt's location at the intersection of Africa, Europe and Asia, and
the influx of foreign rulers, Krause said he was surprised at how stable the
genetics seemed to be over this period. The scientists were particularly
interested in the change in ruling class at the turn of the first millennium
. First came the Hellenistic dynasty, in the aftermath of Alexander the
Great’s conquests, from 332 B.C. to 30 B.C., and then Roman rule from 30 B.
C. to about 400 A.D. And yet the genetics of the Abusir el-Meleq community
appeared to be unperturbed by shifting politics.
The scientists compared these ancient genetics with those of 100 modern
Egyptians and 125 modern Ethiopians that had been previously analyzed. If
you ask Egyptians, they'll say that they have become more European recently,
Krause said. “We see exactly the opposite,” he said.
It was not until relatively recently in Egypt's long history that sub-
Saharan genetic influences became more pronounced. “In the last 1,500 years
, Egypt became more African, if you want,” Krause said.
In their paper, the researchers acknowledged that “all our genetic data
were obtained from a single site in Middle Egypt and may not be
representative for all of ancient Egypt.” In the south of Egypt, the
authors wrote, sub-Saharan influences may have been stronger.
This study left two gaps in the Egyptian timeline that Krause wants to fill,
he said. It is not clear when the African gene flow, present in modern
Egyptians, occurred. Nor could the study determine the origin of the
Egyptians. “The other big question is, 'Where did the ancient Egyptians
come from?' ” Krause said. To answer that, scientists will have to find
genomes “back further in time, in prehistory.”
1.
74519e7dc2ee
【在 w***u 的大作中提到】
: 怎么大家不热烈讨论？这应该是史版诸位都关心的问题。
: https://www.nature.com/news/mummy-dna-unravels-ancient-egyptians-ancestry-1.
: 22069
: https://www.washingtonpost.com/news/speaking-of-science/wp/2017/05/30/dna-
: from-ancient-egyptian-mummies-reveals-their-ancestry/?utm_term=.74519e7dc2ee
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