How Has Game Hunting Made Animals Go Extinct
Israeli scientists wanted to answer a question: What caused the disappearance of the larger animals from prehistoric human diets over fourth dimension?
(photo: Pixabay)
Photo: Pixabay
Humans have had a impact on animal extinctions far longer than commonly idea and our ancestors were hunting species of megafauna into extinction as far back in time equally ane.v million years ago.
This is according to a team of scientists at Tel Aviv Academy in Israel who examined fossil records and argue in a study that prehistoric human being hunters tended to prefer to target the largest casualty animals available because these animals provided the most meat later beingness killed.
Afterwards a comprehensive analysis of data on animal bones collected from dozens of prehistoric sites in and around Israel, the researchers found a continual decline in the size of game animals hunted past early humans as their primary food source ranging from behemothic elephants one.5 meg years agone all the way to gazelles effectually 10,000 years ago.
There is more: information technology was merely after animals larger than deer had been hunted into extinction by the latter date that people in the so-chosen Fertile Crescent in the Heart East began to plough to farming and domesticating animals, likely in order to try and make upwards for the shortfall in bachelor large game.
Scientists have long known that big animals such as mammoths disappeared over time from the fossil record, but a full general hypthesis attributed this to changes in the climate.
Members of the Israeli squad posit a new reason for these extinctions while at the same time they have also sought to answer another question: what drove cultural changes in prehistoric human populations equally they devised always more sophisticated hunting tools until they somewhen turned from hunting and gathering to settled farming and animal husbandry.
"In light of previous studies, our team proposed an original hypothesis that links the 2 questions: We recall that large animals went extinct due to overhunting by humans, and that the change in diet and the need to hunt progressively smaller animals may have propelled the changes in humankind," says Ran Barkai, a professor of prehistoric archaeology at Tel Aviv University.
The researchers focused on the Southern Levant (which encompasses Israel, the Palestinian territories, Hashemite kingdom of jordan, Lebanon and parts of Syria) because the region is an "archaeological laboratory" on business relationship of the density and continuity of prehistoric findings spanning a long period of fourth dimension over a relatively small expanse.
Every bit a result it is "a unique database unavailable anywhere else in the world," notes Jacob Dembitzer, a scholar at Tel Aviv University. "Excavations, which began 150 years agone, have produced evidence for the presence of humans, beginning with Human being erectus who arrived 1.5 million years ago, through the Neandertals who lived here from an unknown fourth dimension until they disappeared about 45,000 years agone, to modernistic humans (namely, ourselves) who came from Africa in several waves, starting around 180,000 years agone," Dembitzer says.
Excavations conducted at 58 prehistoric sites since 1932 have provided a unique sequence of findings from different types of human being settlements in the region over one.5 one thousand thousand years. At some sites various human being groups lived separated by tens of thousands of years, their onetime presence now apparent from different layers of fossils. In all, thousands of bones belonging to 83 animal species have been unearthed and identified.
"Our report tracked changes at a much higher resolution over a considerably longer period of time compared to previous enquiry. The results were illuminating: we found a continual, and very significant, decline in the size of animals hunted by humans over 1.v meg years," explains Shai Meiri, a professor at the university's School of Zoology.
"For example, a third of the bones left behind by Homo erectus at sites dated to about a million years ago, belonged to elephants that weighed upwardly to 13 tons (more than twice the weight of the modern African elephant) and provided humans with 90% of their nutrient. The mean weight of all animals hunted by humans at that time was 3 tons, and elephant bones were found at nearly all sites up to 500,000 years ago," Meiri elucidates.
"Starting about 400,000 years ago, the humans who lived in our region (early on ancestors of the Neandertals and Man sapiens) appear to have hunted mainly deer, along with some larger animals weighing almost a ton, such as wild cattle and horses. Finally, in sites inhabited by modernistic humans, from about 50,000 to 10,000 years ago, approximately 70% of the bones belong to gazelles — an animal that weighs no more than 20-30kg. Other remains found at these later on sites came generally from fallow deer (about twenty%), likewise as smaller animals such equally hares and turtles," the scientist adds.
The findings posed a puzzle: What acquired the disappearance of the larger animals from the area and human diets over time? Was information technology climatic change, equally a widely held theory has it, that drove them into extinction? Or was information technology something else?
To see if climate alter was indeed to blame, the scientists collected climatic and environmental data for the unabridged flow under study roofing more than a dozen cycles of glacial and interglacial periods.
"This information included temperatures based on levels of the oxygen 18 isotope, and rainfall and vegetation evidenced by values of carbon thirteen from the local Soreq Cave. A range of statistical analyses correlating between animal size and climate, atmospheric precipitation, and surround, revealed that climate, and climatic change, had little, if any, impact on animal extinction," Dembitzer says.
The insight prompted the Israeli scientists to suggest what Miki Ben-Dor, an good at the Jacob M. Alkow Department of Archaeology and Aboriginal Near Eastern Cultures, calls "a fascinating hypothesis on the evolution of humankind."
Namely this: "Humans e'er preferred to hunt the largest animals bachelor in their environment until these became very rare or extinct, forcing the prehistoric hunters to seek the next in size," Ben-Dor says. "Every bit a result, to obtain the aforementioned amount of nutrient, every homo species appearing in the Southern Levant was compelled to chase smaller animals than its predecessor, and consequently had to develop more advanced and constructive technologies. Thus, for example, while spears were sufficient for Homo erectus to impale elephants at close range, modern humans developed the bow and arrow to kill fast-running gazelles from a distance."
Nor is this hypothesis limited to the Levant alone. Rather, the aforementioned trends appear to have played out across much of the planet, the scientists say.
"We believe that our model is relevant to human cultures everywhere. Moreover, for the first time, we debate that the driving forcefulness behind the constant improvement in human technology is the continual decline in the size of game. Ultimately, it may well be that 10,000 years ago in the Southern Levant, animals became too small or likewise rare to provide humans with sufficient food, and this could exist related to the advent of agriculture," Prof. Barkai observes.
"In addition, we confirmed the hypothesis that the extinction of large animals was caused by humans — who time and time again destroyed their own livelihood through overhunting. We may therefore conclude that humans have always ravaged their surroundings but were usually clever enough to find solutions for the problems they had created — from the bow and arrow to the agricultural revolution. The environs, withal, e'er paid a devastating price," the scientist adds.
Source: https://www.sustainability-times.com/in-depth/weve-been-hunting-animals-into-extinction-for-1-5-million-years/
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