Although we might blithely refer to the last wintry time period as “ the Ice Age ” , temperature varied a lot . This affected humanity even in the Torrid Zone , but in a bitingly dusty Europe change were much more likely to be a matter of sprightliness and death . A raw direction of analyzing fossil tooth from the epoch yield an meter reading of how the universe of European hunter - gatherer vary until the comer of agribusiness .
member of the human genus have lived in Europefor a very long meter , but as far as we lie with modern humans – gay sapiens – first tried their luck there54,000 years ago . They did n’t appease , but about 45,000 years ago a more lasting line took place .
The world was colder then , but it would get cold still , until bottoming out around 25,000 years ago in what is known as theLast Glacial Maximum(LGM ) . By that time , most of northern and much of central Europe was covered in glaciers . However , Dr Hannes Rathman of the University of Tübingen and Colorado - writer retrieve they ’ve work out out how the approach of those walls of ice affected population further south .
Three ice age skulls from Hohlenstein-Stadel cave. The man (left), a woman (right), and a child (middle) lived around 8,500 years ago when temperatures were not far from today’s and the humans whose ancestors survived the worst of the cold were recolonizing remaining parts of the continent. The shape and lines on their teeth reveal something of their ancestry.Image Credit: Osteological Collection, University of Tübingen
For almost 20,000 years after modern man turn over the continent , the squad find that the populations of westerly and Eastern Europe were intimately related to each other . “ This determination is reproducible with our previous cognition from archaeological studies , which identify far-flung similarity in stone tools , hunt weapon system , and portable artistry from the unlike regions , ” say study co - source Dr Judith Beier in astatement .
The writer attribute this to an open steppe landscape like innovative Ukraine , where herds of mammals formed the principal solid food supply , and locomotion was light and rewarded . condition were colder than when modern humans first moved into the area , but initially , lowly falls in temperature were follow by rise population density .
Then from 28,000 - 14,700 age ago , the populations of East and West diverged . Both regions suffer severe population declines , losing a lot of genetic diverseness in the process , and risking inbreeding .
“ This drastic demographic change was believably make by massive clime change : Temperatures during this catamenia dropped to the lowest values of the entire Upper Paleolithic and culminated in the Last Glacial Maximum , a time when ice sheet get hold of their greatest extent and cover most of northern and key Europe , ” Rathmann said . With the country that was n’t full glaciated turn to tundra , the useable game changed .
Those humans that survived became stray in refugia where conditions were slightly more hospitable , unable to reach their nearest neighbors in distant valleys .
Although most of this was already suspected base on other evidence , the squad found evidence for something new . They remember at some point around the LGM , the population of Western Europe die out entirely . When the region became habitable again , it was descendant of those who had survived in Eastern Europe who were live there .
“ Archaeologists have long debated the influence of climatical changes and the associated new environmental conditions on the human ecology of hunter - gatherers at that meter , ” Rathmann said . “ Due to the limited number of fogy available and their often poor molecular preservation for ancient DNA analysis , it has been very difficult to take out conclusions about the shock of climatic factors on migration , population growth , decline , and extinction . ”
tooth , however , are tougher than anything else in the body . therefore , we have far more fossils of them than anything else . Forensics team sometimes have toidentify victimsof crimes or disasters by their dental records . Rathmann and fellow reached their conclusions by doing something similar for a continent , using ridge and rut patterns on teeth from 450 people who live in Europe between 47,000 and 7,000 years ago to establish their connecter .
“ These traits are inheritable , which entail we can practice them to trace genetical relationships among Ice Age man without requiring well - preserved ancient DNA , ” Rathmann tell .
The squad even used photographs of fogey tooth destroyed in World War II because the sign were visible without requiring microscope .
This data was then bleed through a machine - determine algorithm to identify the most likely relationships between the people the teeth belonged to . The source acknowledge their sample distribution is limited for sure places and periods , leave room for some uncertainty , particularly where it contradicts previous research using other method acting . However , the absolute majority of their conclusions are reproducible with previous determination based on live on desoxyribonucleic acid and ethnical detail , and they hope discoveries of more teeth will improve self-confidence further .
Rathman , Beier , and colleague learn a time when it was cold that repel human populations to the edge or beyond . The fact our young menace is heat does not mean their findings are irrelevant .
“ We should urgently learn from our past if we require to address the complex environmental problems of the future , ” Rathmann said .
The study is release undetermined access in the journalScience Advances .
