How many words does it have to be
This person would have to be in 1990 B.C., because when in B.C., as the years go by, the number of the year gets lower. So the person was 10 in 1995 B.C., and 15 in 1900 B.C.
The main difference is that there is not a significant reservoir of phosphorous in the atmosphere, while both nitrogen and carbon are found in large amounts in the atmosphere.
The answer is adaptive capacities
