科學家發現非洲之外最古老的現代人化石
成員包括紐約州立大學―賓漢頓大學的Rolf Quam，由以色列臺拉維夫大學的Israel Hershkovitz領導的國際大型團隊發現了在非洲之外找到過的最古老現代人類化石。這項發現顯示現代人離開非洲的時間至少比之前認為的還要早了50000年。
「Misliya是項令人興奮的發現。」共同作者，賓漢頓大學的人類學教授Rolf Quam表示，「它呈現了迄今最清楚的證據，顯示我們祖先從非洲遷移出去的時間比過去認為的還要早上許多。這也意謂現代人可能有更長的時間跟其他古人族相遇並產生互動，使他們有更多機會產生文化以及生物層面上的交流。」
這副擁有數顆牙齒的上顎骨化石發現於以色列的Misliya洞窟，其為迦密山上數個史前考古洞穴場址之一。運用幾種不同技術來定年此處的考古材料和化石本身，顯示這具顎骨的年代大致介於17萬5000年至20萬年，將現代人從非洲遷出的時間至少往前推了5萬年。
研究人員依靠微型電腦斷層掃描和三維虛擬模型來分析這具化石遺骸，並跟其他從非洲、歐洲和亞洲發現的人族化石比對。
「雖然Misliya化石在解剖構造上的細節都完全符合現代人，卻也含有一些在尼安德塔人和其他人族身上同樣能見到的特徵。」賓漢頓大學的人類學副教授Quam說。「這項研究的難處之一便是要在Misliya化石上找出只能在現代人身上發現的特徵，它們是最為明確的訊號可以告訴我們Misliya化石究竟是什麼物種。」
考古證據顯示住在Misliya洞穴的居民具有獵捕大型動物的能力並可以控制用火，同時出土的還有一套舊石器時代早中期的石器組，跟在非洲發現，隨著最古老現代人一起發現的石器十分相似。
研究人員表示雖然在非洲曾發現更早的現代人化石，但如果想要瞭解我們所屬物種的演化歷程，現代人從非洲遷出的時間點和路徑是關鍵議題。中東地區是更新世時人族遷移的重要通道，在不同時期曾被現代人和尼安德塔人入主過。
相較於過往研究，Quam表示這項新發現讓我們有機會得知更早以前該區域的人口更迭或者現代人與當地族群的基因交流。最近從古代DNA得出的訊息指出現代人更早之前就已經離開非洲，大概是早於22萬年前，而從Misliya找到的證據確實也與之相符。最近幾個在亞洲發現的考古和化石證據也將現代人首次出現在這些區域的時間更往前推，間接暗示了現代人離開非洲的時間。
這篇文章「The earliest modern humans outside Africa」發表於期刊《科學》(Science)。
Scientists discover oldest known modern
human fossil outside of Africa
A large international research team, led by Israel Hershkovitz
from Tel Aviv University and including Rolf Quam from Binghamton University,
State University of New York, has discovered the earliest modern human
fossil ever found outside of Africa. The finding suggests that modern humans
left the continent at least 50,000 years earlier than previously thought.
“Misliya is an exciting
discovery,” says Rolf Quam, Binghamton University anthropology professor and a
coauthor of the study. “It provides the clearest evidence yet that our
ancestors first migrated out of Africa much earlier than we previously
believed. It also means that modern humans were potentially meeting and interacting
during a longer period of time with other archaic human groups, providing more
opportunity for cultural and biological exchanges.”
The fossil, an upper
jawbone with several teeth, was found at a site called Misliya Cave in Israel,
one of several prehistoric cave sites located on Mount Carmel. Several dating
techniques applied to archaeological materials and the fossil itself suggest
the jawbone is between 175,000-200,000 years old, pushing back the modern human
migration out of Africa by at least 50,000 years.
Researchers analyzed the
fossil remains relying on microCT scans and 3D virtual models and compared it
with other hominin fossils from Africa, Europe and Asia.
“While all of the
anatomical details in the Misliya fossil are fully consistent with modern
humans, some features are also found in Neandertals and other human groups,”
said Quam, associate professor of anthropology at Binghamton. “One of the
challenges in this study was identifying features in Misliya that are found
only in modern humans. These are the features that provide the clearest signal
of what species the Misliya fossil represents.”
The archaeological evidence
reveals that the inhabitants of Misliya Cave were capable hunters of large game
species, controlled the production of fire and were associated with an Early
Middle Paleolithic stone tool kit, similar to that found with the earliest
modern humans in Africa.
While older fossils of
modern humans have been found in Africa, the timing and routes of modern human
migration out of Africa are key issues for understanding the evolution of our
own species, said the researchers. The region of the Middle East represents a
major corridor for hominin migrations during the Pleistocene and has been
occupied at different times by both modern humans and Neandertals.
This new discovery opens
the door to demographic replacement or genetic admixture with local populations
earlier than previously thought, said Quam. Indeed, the evidence from Misliya
is consistent with recent suggestions based on ancient DNA for an earlier
migration, prior to 220,000 years ago, of modern humans out of Africa. Several
recent archaeological and fossil discoveries in Asia are also pushing back the
first appearance of modern humans in the region and, by implication, the
migration out of Africa.
The article, “The earliest
modern humans outside Africa,” was published in Science Magazine.
原始論文：Israel
Hershkovitz, Gerhard W. Weber, Rolf Quam, Mathieu Duval, Rainer Grün, Leslie
Kinsley, Avner Ayalon, Miryam Bar-Matthews, Helene Valladas, Norbert Mercier,
Juan Luis Arsuaga, María Martinón-Torres, José María Bermúdez de Castro, Cinzia
Fornai, Laura Martín-Francés, Rachel Sarig, Hila May, Viktoria A. Krenn,
Viviane Slon, Laura Rodríguez, Rebeca García, Carlos Lorenzo, Jose Miguel
Carretero, Amos Frumkin, Ruth Shahack-Gross, Daniella E. Bar-Yosef Mayer,
Yaming Cui, Xinzhi Wu, Natan Peled, Iris Groman-Yaroslavski, Lior Weissbrod,
Reuven Yeshurun, Alexander Tsatskin, Yossi Zaidner, Mina Weinstein-Evron. The
earliest modern humans outside Africa. Science, 26 Jan 2018
456-459 DOI: 10.1126/science.aap8369
引用自：Binghamton University. "Scientists
discover oldest known modern human fossil outside of Africa."
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