Humans, not climate change, caused herbivores mega-extinction – Israeli study
Research by Tel Aviv University scholars analyzed data and remains from dozens of sites in the southern Levant.
For hundreds of thousands of years, prehistoric humans living in the area of present-day Israel and its surroundings hunted and fed on the largest available animals until the beasts became extinct and then the people moved on to the next biggest species, new research from Tel Aviv University scholars has shown.
Over the course of around 1.5 million years, the ancient populations of the region consumed progressively smaller species – starting from mighty, one-ton elephants and eventually getting down to 30-kilogram gazelles. By doing so, they brought terrible disruption to the ecosystem, but they were also forced to evolve and develop new skills and technologies to capture their new sources of food.
The study – whose results were published in Quaternary Science Reviews – intended to address both issues: What caused the mass extinction of mega-herbivores, often attributed to ‘climate change’, and what fueled the extraordinary development of humans into what they are today?
The team analyzed data from 58 prehistoric sites in the area, considering 133 layers from different time periods and thousands of bones belonging to 83 animal species.
“We considered the southern Levant (Israel, the Palestinian Authority, Southwest Syria, Jordan and Lebanon) to be an ‘archaeological laboratory’ due to the density and continuity of prehistoric findings covering such a long period of time over a relatively small area – a unique database unavailable anywhere else in the world,” said Jacob Dembitzer.
“Excavations, which began 150 years ago, have produced evidence for the presence of humans, beginning with Homo erectus who arrived 1.5 million years ago, through the Neanderthals who lived here from an unknown time until they disappeared about 45,000 years ago, to modern humans (namely, ourselves) who came from Africa in several waves starting around 180,000 years ago,” he said.
Image: Tel Aviv University
The researchers determined that around a million years ago, elephants twice as large as contemporary African ones, comprised 90 percent of the food of early humans (Homo erectus). Elephant bones represented approximately a third of the remains found at the sites from the period and bones were present in almost all sites up to approximately 500,000 years ago.
“Starting about 400,000 years ago, the humans who lived in our region – early ancestors of the Neanderthals and Homo sapiens – appear to have hunted mainly deer, along with some larger animals weighing almost a ton, such as wild cattle and horses,” noted Prof. Shai Meiri.
“Finally, in sites inhabited by modern humans, from about 50,000 to 10,000 years ago, approximately 70 percent of the bones belong to gazelles – an animal that weighs no more than 20-30 kg. Other remains found at these later sites came mostly from fallow deer (about 20 percent), as well as smaller animals such as hares and turtles.”
Image: Tel Aviv University
Procuring the same amount of food from smaller animals, however, required more effort and the development of new techniques and tools.
The researchers also examined the possible correlation between the disappearance of different species and the evolution of climate in the region but found no tangible connection between the two phenomena.
“A widely accepted theory attributes the extinction of large species to climate changes through the ages,” Dembitzer noted. “To test this, we collected climatic and environmental data for the entire period, covering more than a dozen cycles of glacial and interglacial periods.”
The data included temperatures, rainfall and vegetation.
“A range of statistical analyses correlating between animal size and climate, precipitation and environment revealed that climate – and climate change – had little if any impact on animal extinction,” Dembitzer said.The results of the study have far-reaching implications that go well beyond the scope of prehistoric southern Levant, the researchers pointed out.
“We believe that our model is relevant to human cultures everywhere,” said Barkai. “For the first time, we argue that the driving force 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 too rare to provide humans with sufficient food, and this could be related to the advent of agriculture.
“A range of statistical analyses correlating between animal size and climate, precipitation and environment revealed that climate – and climate change – had little if any impact on animal extinction,” Dembitzer said.
The results of the study have far-reaching implications that go well beyond the scope of prehistoric southern Levant, the researchers pointed out.
“We believe that our model is relevant to human cultures everywhere,” said Barkai. “For the first time, we argue that the driving force 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 too rare to provide humans with sufficient food, and this could be related to the advent of agriculture.
“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 over-hunting,” he remarked. “We may therefore conclude that humans have always ravaged their environment but were usually clever enough to find solutions for the problems they had created – from the bow and arrow to the agricultural revolution. The environment, however, always paid a devastating price.”
See more here: jpost.com
Header image: Tel Aviv University
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Herb Rose
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Another example of modern “scientist” beginning with the assumption our ancestors were complete idiots and were responsible for everything bad that happened. In order to get food they needed to hunt the largest most dangerous animals to extinction before they could hunt less dangerous and more plentiful game. Just because most of the present population (including scientists) are stupid doesn’t mean that this was always true. The only way the human species could survive was by intelligence, not because of their formidable physical traits.
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Joseph Olson
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Human ancestors, the LEMURS hunted the giant dinosaurs to extinction, not climate change by a giant asteroid that “supposedly” ended the Jurassic Period. Stone age cavemen exterminated the 900 pound Sabre toothed tigers and packs of 400 pound dire wolves, not the asteroid that hit the Canadian ice pack that started the Holocene Interglacial warming period 12,000 years ago. University studies are over priced science fiction.
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Jerry Krause
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Hi Herb, Joseph and other PSI Readers,
For your information the following is from THE MARTYRS OF SCIENCE by David Brewster (1840).
“It is not easy to ascertain the exact time when Galileo became a convert to the doctrines of Copernicus, or the particular circumstances under which he was led to adopt them. … This assertion, however, is by no means probable; and it has been ably shown, by the latest biographer of Galileo, [5] that, in his dialogues on the Copernican sysem, our author give the true account of his own conversion. This passage is so interesting, that we shall give it entire.”
[5]. Life of Galileo, in Library of Useful Knowledge, p. 9.
“I cannot omit this opportunity of relating to you what happened to myself at the time when this opinion (the Copernican system) began to be discussed. I was then a very young man, and had scarcely finished my course of philosophy, which other occupations obliged me to leave off, when there arrived in this country from Rostoch, a foreigner, whose name, I believe, was Christian Vurstisius (Wurteisen), a follower of Coperincus. This person delivered, on this subject, two or three lectures in a certain academy, and to a crowded audience. Believing that several were attracted more by the novelty of the subject than by any other cause, and being firmly persuaded that this opinion was a piece of solemn folly, I was unwilling to be present. Upon interrogating, however, some of those who were there, I found that they all made it a subject of merriment, with the exception of one, who assured me that it was not a thing wholly ridiculous. As I considered this individual to be both prudent and circumspect, I repented that I had not attended the lectures; and, whenever I met any of the followers of Copernicus, I began to inquire if they had always been of the same opinion. I found that there was not one of them who did not declare that he had long maintained the very opposite opinions, and had not gone over to the new doctrines till he was driven by the force of argument. I next examined them one by one, to see if they were masters of the arguments on the opposite side; and such was the readiness of their answers, that I was satisfied they had not taken up this opinion from ignorance or vanity. On the other hand, whenever I interrogated the Peripateiics and the Ptolemeans—and, out of curiosity, I have interrogated not a few—respecting their perusal of Copernicus’s work, I perceived that there were few who had seen the book, and not one who understood it. Nor have I omitted to inquire among the followers of the Peipatetic doctrines, if any of them had ever stood on the opposite side; and the result was, that there was not one. Considering then, that nobody followed the Copernican doctrine, who had not previously held the country opinion, and who was not well acquainted with the arguments of Aristotle and Ptolemy; while, on the other hand, nobody followed Ptolemy and Aristotle, who had before adhered to Copernicus, and had gone over from him into the camp of Aristotle;—weighing, I day, these things, I began to believe that, if any one who rejects an opinion which he has imbibed with his opinion held only by a few, condemned by all the schools, and really regarded as a great paradox, it cannot be doubted that he must have been induced, not to say driven, to embrace it by the most cogent arguments. On this account I have become very curious to penetrate to the very bottom of the subject,” [6]
[6] Systems Cosnicum, Dial. ii. P. 121”. My copy of Brewster’s biography does not have page numbers.
Have a good day, Jerry
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James McGinn
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Jerry:
whenever I interrogated the Peripateiics and the Ptolemeans—and, out of curiosity, I have interrogated not a few—respecting their perusal of Copernicus’s work, I perceived that there were few who had seen the book, and not one who understood it.
Meteorology is Inundated with Superstition
https://youtu.be/lMQAhTc0hYk
James McGinn / Genius
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Jerry Krause
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Hi James,
Before you get to the “superstition point” you must demonstrate that you know and understand that which has already been written before you appear on the scene. Which seems the point of Galileo’s personal statements.
Have a good day, Jerry
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James McGinn
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You are confused. Clearly G is saying that the people that reject C have never actually considered his argument(s).
My model explains what your model dismisses:
16:28
NOW PLAYING
WATCH LATER
ADD TO QUEUE
How The Jetstream Maintains Its Momentum
James McGinn / Genius
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Jerry Krause
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Hi James,
Galileo concluded: “On this account I have become very curious to penetrate to the very bottom of the subject.”
We (I) know about the experiments Galileo conducted and the telescope he made after being challenged into action by a person first used single lenses to help people to better read and understood how the different lens ‘bent’ light. So he used a combination of lens (I have no knowledge of how many or what combination he used, but Galileo immediately understood and invented his telescope with which he could see natural satellites circling Jupiter and could see the phases of Venus just as he, and we, could see the phases of the moon. And Galileo used words and didn’t need a fast, stop-action, VIDEO to define that which he simply observed relative to the idea that things twice as heavy fell twice as fast. For it was very easy to design an experiment which illustrated that this idea was wrong. I have yet to read one specific observed thing that you consider that Pauling got absolutely wrong.
I will point out one thing that Galileo got wrong. He believed that “argument” had a role to play in this activity we describe as being SCIENCE. SCIENCE totally based upon reproducible observations (sometimes measurements). Which some attempt to explain. as if their explanations will lend validity to what is clearly observed and needs no explanation.
Have a good day, Jerry.
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James McGinn
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You are just a totally convoluted thinker Jerry.
Jerry Krause
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Hi James,
Had to read the definition of “convoluted” to even begin to understand your comment. But as I have pondered your comment, I am complemented by it. I am not a straight line ponderer. I ask: What was Feynman’s understanding of what the IR-Thermometer (device).measured? I can no longer ask him but I can ask you: Of what does the IR-thermometer measure the temperature???
Have a good day, Jerry
James McGinn
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Why don’t you tell us what you think Galileo intended in the passage above.
Jerry Krause
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Hi James,
I can remember that the cause of high pressure regions and/or low pressure regions have been discussed. Right now the movement of a cold air mass into the coastal regions of Oregon and Washington is expected to continually decrease air temperatures for the next several with the result we might expect below 32 F temperatures and snow in the Willamette Valley. And the atmospheric pressure is dropping toward the extreme low pressures we have experienced during any season of the year.
It would to seem that low temperature atmosphere should be more dense and therefore the pressure should be higher, not lower. Can you help straighten out my convoluted THINKING!!!
Have a good day, Jerry
Jerry Krause
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Hi James,
“Why don’t you tell us what you think Galileo intended in the passage above.” I have no idea what anyone else thinks and I am clueless as to what passage you believe he might have had any though upon!!!
Have a good day, Jerry
James McGinn
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It would to seem that low temperature atmosphere should be more dense
If the pressure stays the same then, yes, that would be true. But what normally happens is that with a decrease in temperature we get a corresponding decrease in pressure.
and therefore the pressure should be higher, not lower.
I think what you mean is that the pressure would have to increase to achieve the same density. Yes, this is true too.
Do a search on the following:
See Ideal Gas Law: PV=nRT
Can you help straighten out my convoluted THINKING!!!
Hope this helps.
James McGinn / Genius
James McGinn
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Play your stupid games, Jerry. I’m just telling you that to understand what Galileo intended here you have to consider that he was being watched by the thought police of their day, the Catholic church. Now you can go back to your silly meanderings.
Jerry Krause
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Hi Herb and Joseph,
Because I seem to remember that you two have doubted the validity of an IR Thermometer’s measurements, I quote a bit from Richard Feynman’s book “WHAT DO YOU CARE WHAT OTHER PEOPLE THINK?” Bantam edition/ November 1989. For I am not sure if he actually understood what a SURFACE TEMPERATURE actually is (was).
“We also heard about the low temperatures before the launch from a man named Charlie Stevenson, who was in charge of the crew. He said the temperature had gone down to 22 degrees during the night, but his crew go readings as low as 8 degrees at some places on the launch pad, and they couldn’t understand why.” pp 161
“I ran down to Charlie Stevenson’s place to see more pictures of the launch. I also found out more about the unusually low temperature readings. The guys were very cooperative, and wanted me to work with them. … On Saturday I talked to the guy who had actually taken the temperature readings the morning of the launch—a nice fella named B. K. Davis. Next to each temperature he had written the exact time he had measured it, and then took a picture of it. You could see large gaps between the times as he climbed up and down the big launch tower. He measured the temperature of the air, the rocket, the ground, the ise, and even a puddle with antifreeze in it. He did a very complete job.
“NASA had a theoretical calculation of how the temperatures should vary around the launch pad: they should have been more uniform, and higher. Somebody thought that heat radiating to the clear sky had something to do with it. But then someone else noticed that BK’s reading for the slush was much lower than the photograph indicated: at 8 degrees, the slush—even with antifreeze in it—should have been frozen solid.” [I will come back to this as I continue]
“Then we looked at the device the ice crew used for measuring the temperatures. I got the instruction manual out, and found that you’re suppose to put the instrument out in the environment for at least 20 minutes before using it. Mr. Davis said he had taken it out of the box—at 70 degrees—and began making measurements right away. Therefore we had to find out whether the errors were reproducible. In other words, could the circumstances be duplicated.?
“On Monday I called up the company that made the device, and talked to one of their technical guys: “Hi, my name is Dick Feynman,” I said. “I’m on the commission investigating the ‘Challenger’ accident, and I have some questions about your infrared scanning gun …”. “May I call you right back?” he says. “Sure.”
“After a little while he calls me back: “I’m sorry, but it’s proprietary information. I can’t discuss it with you.”
“By this time I realized that the real difficulty6 was: the company was scared green that we were going to blame the accident on their instrument. I said, “Sir, your scanning gun had nothing to do with the accident. It was used by people here in a way that’s contrary to the procedures in your instruction manual, and I’m trying to figure out if we can reproduce the errors and determine what the temperatures really were that morning. To do this, I need to know more about your instrument.”
“The guy finally came around, and become quite cooperative. With his help, I advised the ice-crew on an experiment. They cooled a room down to about 40 degrees, and put a big block of ice in it—ice, you can be sure the surface temperature is 32 degrees. The they brought in the scanning gun from a room which was 70 degrees inside, and made measurements of the ice block every 30 seconds. They were able to measure how far off the instrument was as a function of time.
“Mr. Davis had written his measurements so carefully that it was very easy to fix all the numbers. And then, remarkably, the recalculated temperatures were close to what was expected according to the theoretical model. It looked very sensible.” Pages 164-166
“But then someone else noticed that BK’s reading for the slush was much lower than the photograph indicated: at 8 degrees, the slush—even with antifreeze in it—should have been frozen solid.”
Just before this statement, was the statement: “Somebody thought that heat radiating to the clear sky had something to do with it.”
Relative to this ‘overlooked’ statement, do either of you consider that heat radiating to a clear sky might have something to do with temperatures measured the next morning???
Have a good day, Jerry
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