...the population of the world used to be bigger than it is now and/or is continuously shrinking?
A) The ratio of the geometric sequence is 1/2, not 2.
B) Geometric sequences cannot be extended backward in time.
C) Many of the ancestors have died.
D) We cannot determine the first term of the geometric sequence.
E) The ancestor tree ignores the existence of brothers and sisters.
"An ancestor family tree shows that the farther you go back in time, the more ancestors you have. You have 16 great-great grandparents in the 5th generation back, and you have about half a million ancestry who lived 500 years ago (the 20th generation back). The strange this is, this makes it seem like the population of the world must be getting smaller, when we know it is actually getting bigger all the time."
A) The ratio of the geometric sequence is 1/2, not 2.
B) Geometric sequences cannot be extended backward in time.
C) Many of the ancestors have died.
D) We cannot determine the first term of the geometric sequence.
E) The ancestor tree ignores the existence of brothers and sisters.
"An ancestor family tree shows that the farther you go back in time, the more ancestors you have. You have 16 great-great grandparents in the 5th generation back, and you have about half a million ancestry who lived 500 years ago (the 20th generation back). The strange this is, this makes it seem like the population of the world must be getting smaller, when we know it is actually getting bigger all the time."