Lack of provisional acceptance of the overkill hypothesis, ..
The Second-Order Predation Hypothesis says that as humans entered the New World they continued their policy of killing predators, which upset the of the continent causing , environmental exhaustion, and environmental collapse. The hypothesis accounts for changes in animal, plant, and, human populations.
Martin, Prehistoric overkill, in: P.S
With the benefit of hindsight, Field's memoirs claim that, as he laid out the bones in Chicago, "the pelvic girdle was definitely feminine" - yet, as noted above, his article of 1927 still saw the skeleton as a young man!
Lack of provisional acceptance of theoverkill hypothesis, when no viable alternatives exist, may be in partbecause this unconventional hypothesis violates a strong socioculturalbias, the image of prehistoric man as the "noble savage".
Prehistoric overkill hypothesis; ..
The PEM is the only test of multiple hypotheses and is the only model to specifically test combination hypotheses by artificially introducing sufficient climate change to cause extinction. When Overkill and Climate Change are combined they balance each other out. Climate Change reduces the number of plants, Overkill removes animals, therefore fewer plants are eaten. Second-Order Predation combined with Climate Change exacerbates the effect of Climate Change. (results graph at right).
"Evidence supporting the prehistoric overkill hypothesis ..
This has been supported by a computer model, the Pleistocene Extinction Model (PEM), which, using the same assumptions and values for all variables (herbivore population, herbivore recruitment rates, food needed per human, herbivore hunting rates, etc) other than those for hunting of predators. It compares the Overkill hypothesis (predator hunting = 0) with Second-Order Predation (predator hunting varied between 0.01 and 0.05 for different runs) . The findings are that Second Order-Predation is more consistent with extinction than is Overkill (results graph at left).
Quaternary extinction event - Wikipedia
One suggestion is that pathogens were transmitted by the expanding via the domesticated they brought with them. Unfortunately for such a theory it can not account for several major extinction events, notably Australia and North America. Dogs did not arrive in Australia until approximately 35,000 years after the first humans arrived and approximately 30,000 years after the megafaunal extinction was complete and as such can not be implicated. In contrast numerous species including wolves, mammoths, camelids and horses had emigrated continually between Asia and North America over the past 100,000 years. For the disease hypothesis to be applicable in the case of the Americas it would require that the population remain immunologically naive despite this constant transmission of genetic and pathogenic material.
27/12/2017 · Can the Overkill Hypothesis be falsified
Debate around this hypothesis has included, among other things, the lack of an impact crater, relatively small increased level of in the soil, and the highly improbable nature of such an event.