It is a natural tendency of organisms to produce more progeny,...

According to Charles Darwin's observations on the natural tendency of organisms to overproduce, even the slowest breeding animals can produce an enormous number of offspring over time.

Darwin calculated that a single pair of elephants, which are considered among the slowest breeders, would produce approximately $19,000,000$ (1,90,00,000$) descendants in a span of 750$ years if all of them survived and reproduced.

Answer: 1,90,00,000