Self-study
Ancient humans in eastern North America hunted mammoths until the mammoth disappeared from the area around 13,000 years ago. █████████ █ ██████ ████ ████ ██ █████████ ████ ███████ █ ███████ ███ █████ ██ ██ ███████ ██████████ ██ ███████ █████ ████████ ████ █████ ████ ███ ██████████ ███ ████████ ██ █ ████ ████ ████████ █████ ██ ████ █████
Summary
The author concludes that a certain ancient settlement in eastern North America was occupied by humans at a time when mammoths lived in the area of the settlement.
What makes the author think this?
Because a fossil bone with an engraving that depicts a mammoth was found in the ancient settlement.
Notable Assumptions
The author assumes that the fossil bone engraving that depicts a mammoth was made by humans at the settlement when mammoths were still in existence.
The author also assumes that the fossil bone was not brought to the ancient settlement from a different location.
2.
The argument requires the assumption ████
a
the engraving was ████ ██████ ███ ████ ████ ███ ██████████ ███ ████████
Necessary, because if it were not true — if the engraving was NOT made during the time when the settlement was occupied — then we have no reason to think that the engraving is evidence that the settlement was occupied when mammoths lived in the area. If (A) were negated, the engraving could have been made long after the settlement was occupied.
b
the fossil on █████ ███ █████████ ███ ████ ███ ███ █ ███████ ████
Not necessary, because even if the fossil on which the engraving was made WAS a mammoth bone, that doesn’t undermine the author’s theory about the timeline of the engraving and the significance of the fact it depicts a mammoth.
c
when mammoths disappeared ████ ███████ █████ ████████ █████ ████ ██ ████████ ████ ████████ ██ █████ ███████
Not necessary, because even if it were the case that SOME mammoths were still left in North America after mammoths disappeared from eastern North America, the argument concerns only eastern North America. The conclusion is that the settlement was occupied at a time when mammoths “lived in this area.” So the presence of mammoths in other parts of the country are not relevant.
d
the engraving technique ████████ ██ ███ ██████ ███ ██████ ██ ███████ █████ ███████
Not necessary, because even if the engraving technique used on the fossil was NOT unique to eatsern North America, we still know that the engraving depicts a mammoth, and that depiction can still be evidence of the presence of mammoths at the time the engraving was made.
e
there is no ██████████ ███ ██ ██████ ████ ███ █████████ ██ ███ ███████ ███ ████
Not necessary, because even if there IS a scientific way of dating the engraving of the mammoth, that doesn’t undermine the author’s theory about the timeline of the engraving and the significance of the fact it depicts a mammoth.