I was just reading Guns Germs and Steel, and Jared Diamond made a convincing argument that humans are most likely responsible. Wherever humans go, the large megafauna seem to die shortly afterwards. Humans are pretty effective hunters, and hunt in different ways than other animals. Animals evolved to defend themselves from wolves, not spears or being chased off cliffs.
The reason megafauna didn't die off in Africa is because humans evolved alongside them. As humans gradually became better hunters, the animals had time to adapt. But now that humans have guns, and that's starting to change too.
The alternative hypothesis of climate change doesn't really make sense, because there have been many periods of climate change in the past that didn't wipe out all the megafauna.
Megafauna in Africa has two different characteristics not found in the Arctic:
1. Scavenger species which would've nullified the prize of the prey [you can't easily drag an elephant away for butchering]
2. Things in the tropics rot fast. Your megafauna will either rot or more likely eaten by scavengers before you have a chance to hack something useful off. And, you're likely not keen on attracting predators who might see you as competition for the foodsource you just produced.
I see this university press release and the paper to which in points[1] both came out in October 2015. I wonder if there has been some follow-up on this by other scientists yet.
Hancock's position is the archaeological model from this article is full of holes; created by multiple assumptions based on assumptions re: radiocarbon dating & general lack of critical thinking.
Instead he points to evidence of two comets hitting the ice caps in the last ice age (younger Dryas period), which melted the ice, causing "fire to rain" & worldwide flooding.
> "unconventional" (1) and less charitably as "crank" (2) and "woo" (3)
those are socially defined terms (i.e. they don't say much about the validity or invalidity of a theory). only the facts & the system that ties the facts together.
the thing is, many of our "facts" poorly constructed assumptions. one has to be discerning & not afraid of ambiguity, nuance, & unknowns. i recommend to not lock yourself into a predefined box.
from your perspective, you don't see this as a "rebuttal". from my perspective, i see it as a rebuttal. ad hominem techniques are not evidence for a position.
i'm also open to neither of these models as being correct.
indeed, we choose what we are skeptical toward, based on our existing bias...
I wouldn't have down voted you. You stated Hancock's position and your post should have been treated as a point of debate. But I agree that Hancock's arguments are pretty much refuted. Occams's Razor -- the archaeological evidence, which seems to be mounting in many different sudies, trumps any vague theories about comets.
But hell, this is science. Come up with enough evidence to the contrary and it will be backed. But the archaeological evidence is looking pretty good at present.
precisely why i find hancock's model more compelling. it better fits occam's razor. if you look at the models in more detail, the bugs become obvious
> trumps any vague theories about comets
the evidence is mounting & more attention is being paid. like software, social,geological,archaeological,etc models are a developed system. studies are being conducted that show things like a layer of nanodiamonds across "50 million square kilometers across the Northern Hemisphere at the Younger Dryas boundary".
here are some models that were once "vague", "woo", "controversial"
the earth being 4.5 billion years old, plate tetonics, the earth orbiting the sun.
> But the archaeological evidence is looking pretty good at present
funny how all sides declare victory with their "evidence" ;-)
note the "absence of a crater" is explained by the comet impacting the ice cap (a thick layer of ice) during the younger dryas period. seems worthy of consideration...
i encourage you to look into the methodology of radio carbon dating & other technologies; also look into the advantages/disadvantages of each technology...
The reason megafauna didn't die off in Africa is because humans evolved alongside them. As humans gradually became better hunters, the animals had time to adapt. But now that humans have guns, and that's starting to change too.
The alternative hypothesis of climate change doesn't really make sense, because there have been many periods of climate change in the past that didn't wipe out all the megafauna.