Early Homo sapiens groups in Europe faced subarctic climates
New insights into the climatic backdrop for an early wave of dispersal of
our species into Europe during the last glacial period

Date:
September 22, 2021
Source:
Max Planck Institute for Evolutionary Anthropology
Summary:
Using oxygen stable isotope analysis of tooth enamel from animals
butchered by humans at the site of Bacho Kiro Cave, Bulgaria,
researchers show that human groups belonging to an early wave of
dispersal of our species into Europe were faced with very cold
climatic conditions while they occupied the cave between about
46,000 and 43,000 years ago.

Archaeological remains at Bacho Kiro Cave currently represent
the oldest known remnants of Upper Palaeolithic Homo sapiens
in Europe, and thus open a unique window into the time when our
species started to move out of the Levant and establish itself
across the mid latitudes of Eurasia as part of an archaeological
phenomenon called the Initial Upper Palaeolithic.



FULL STORY ==========================================================================
The process how our species dispersed into new environments at that
time represents an important evolutionary turning point that ultimately
led to Homo sapiens populating all continents and a large diversity of
climate zones and environments. The mechanisms that facilitated initial
waves of expansion remain debated, but a majority of models based on
the correlation of archaeological sites with spatially distant climatic archives has so far indicated that human groups relied on warmer climatic conditions to spread into new, more northern, environments.


========================================================================== Using evidence directly from the archaeological layers of Bacho Kiro
Cave the Max Planck team was now able to show that humans have been
enduring very cold climatic conditions, similar to the ones typical
for present-day northern Scandinavia, for several thousand years. "Our
evidence shows that these human groups were more flexible with regard
to the environments they used and more adaptable to different climatic conditions than previously thought," says lead author Sarah Pederzani,
a researcher at the Max Planck Institute for Evolutionary Anthropology
and the University of Aberdeen. Jean-Jacques Hublin, director of the
Department of Human Evolution at the Max Planck Institute, adds: "Using
these new insights, new models of the spread of our species across Eurasia
will now need to be constructed, taking into account their higher degree
of climatic flexibility." Archaeological materials from Bacho Kiro Cave
in Bulgaria By directly using archaeological materials, such as the
remains of herbivores butchered by humans, to generate climatic data
the palaeoclimate research team -- led by Pederzani and Kate Britton,
also a researcher at Max Planck Institute for Evolutionary Anthropology
and the University of Aberdeen -- was able to establish a very robust
record of local climatic conditions that specifically relates to the
times when humans were inhabiting Bacho Kiro Cave.

"This technique enables a more confident assignment of local climatic
context compared to the more commonly used chronological correlation
between archaeological data and climatic archives from different
localities that formed the basis of much of the existing research on
human climatic adaptability -- it really gives us insight into what life
was like 'on the ground'," says Britton.

"However, due to the time consuming nature of the analysis and the
reliance on the availability of particular animal remains, oxygen
isotope studies or other ways of generating climatic data directly from archaeological sites remain scarce for the time period when Homo sapiens
first spread across Eurasia," adds Pederzani. Indeed, this Max Planck
study is the first study conducted in the context of the Initial Upper Palaeolithic and could therefore yield such surprising results.

Highly resolved record of past temperatures spanning more than 7,000 years Pederzani spent one year conducting lab work from drilling series of small samples from the animal teeth through wet chemistry preparation and stable isotope ratio mass spectrometry to obtain all the necessary data. "Through
this time intensive analysis that included a total of 179 samples, it was possible to obtain a very highly resolved record of past temperatures, including summer, winter and mean annual temperature estimates for human occupations spanning more than 7,000 years," says Pederzani.

Renewed excavations at Bacho Kiro Cave conducted by an international
team led by Max Planck researchers Jean-Jacques Hublin, Tsenka Tsanova
and Shannon McPherron, and Nikolay Sirakov of the National Institute of Archaeology with Museum at the Bulgarian Academy of Sciences in Sofia, Bulgaria, started in 2015 and have yielded a rich archaeological record
of human activity at the cave including the remnants of occupations
that represent the earliest known occurrence of Upper Palaeolithic Homo
sapiens in Europe. Deposits in the lower portion of the site contained
a large number of animal bones, stone tools, pendants and even human
fossils and formed the basis of the climatic study to investigate the environmental conditions that humans experienced when they first spread
into Southeast Europe from the Levant.

========================================================================== Story Source: Materials provided by Max_Planck_Institute_for_Evolutionary_Anthropology. Note: Content may
be edited for style and length.


========================================================================== Journal Reference:
1. Sarah Pederzani, Kate Britton, Vera Aldeias, Nicolas Bourgon, Helen
Fewlass, Tobias Lauer, Shannon P. McPherron, Zeljko Rezek,
Nikolay Sirakov, Geoff M. Smith, Rosen Spasov, N.-Han Tran,
Tsenka Tsanova, Jean- Jacques Hublin. Subarctic climate for the
earliest Homo sapiens in Europe. Science Advances, 2021; 7 (39)
DOI: 10.1126/sciadv.abi4642 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/09/210922143250.htm

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